Electronic circuits and computing devices

Abstract

To provide an electronic circuit and a calculation device capable of improving characteristics.SOLUTION: An electronic circuit includes a first quantum bit, a second quantum bit, a first coupler, a first reading conductive member, and a first filter. The first coupler includes a first resonator and a second resonator. The first resonator can be coupled with the first quantum bit. The second resonator can be coupled with the second quantum bit. The first filter includes a first filter portion, a first other filter portion, and a first reading portion. The first filter portion can be coupled with the first resonator. The first other filter portion can be coupled with the second resonator. The first reading portion can be coupled with the first reading conductive member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Embodiments of the present invention relate to electronic circuits and computing devices. [Background technology]

[0002] For example, electronic circuits including a plurality of nonlinear elements are used in computing devices, and improved performance is desired in electronic circuits and computing devices. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] MD Reed et al., Appl. Phys. Lett. 96, 203110 (2010). Summary of the Invention [Problem to be solved by the invention]

[0004] Embodiments of the present invention provide electronic circuits and computing devices that can have improved performance. [Means for solving the problem]

[0005] According to an embodiment of the present invention, an electronic circuit includes a first quantum bit, a second quantum bit, a first coupler, a first readout conductive member, and a first filter. The first coupler includes a first resonator and a second resonator. The first resonator is couplable with the first quantum bit. The second resonator is couplable with the second quantum bit. The first filter includes a first filter portion, a first other filter portion, and a first readout portion. The first filter portion is couplable with the first resonator. The first other filter portion is couplable with the second resonator. The first readout portion is couplable with the first readout conductive member. [Brief explanation of the drawings]

[0006] [Figure 1]FIG. 1 is a schematic plan view illustrating an electronic circuit according to the first embodiment. [Figure 2] FIG. 2 is a circuit diagram illustrating an electronic circuit according to the first embodiment. [Figure 3] FIG. 3 is a schematic view illustrating the characteristics of the electronic circuit according to the first embodiment. [Figure 4] FIG. 4 is a schematic plan view illustrating the electronic circuit according to the first embodiment. [Figure 5] FIG. 5 is a schematic plan view illustrating the electronic circuit according to the first embodiment. [Figure 6] FIG. 6 is a schematic plan view illustrating the electronic circuit according to the first embodiment. [Figure 7] 7(a) to 7(e) are schematic cross-sectional views illustrating a part of the electronic circuit according to the first embodiment. [Figure 8] 8(a) to 8(c) are schematic cross-sectional views illustrating a part of the electronic circuit according to the first embodiment. [Figure 9] 9A and 9B are schematic cross-sectional views illustrating a part of the electronic circuit according to the first embodiment. [Figure 10] 10A and 10B are schematic cross-sectional views illustrating a part of the electronic circuit according to the first embodiment. [Figure 11] FIG. 11 is a schematic plan view illustrating the electronic circuit according to the first embodiment. [Figure 12] FIG. 12 is a schematic plan view illustrating the electronic circuit according to the first embodiment. [Figure 13] FIG. 13 is a schematic cross-sectional view illustrating the electronic circuit according to the first embodiment. [Figure 14] FIG. 14 is a graph illustrating the characteristics of the electronic circuit according to the first embodiment. [Figure 15] FIG. 15 is a graph illustrating the characteristics of the electronic circuit according to the first embodiment. [Figure 16] FIG. 16 is a schematic view illustrating the electronic circuit according to the first embodiment. [Figure 17]FIG. 17 is a schematic view illustrating the electronic circuit according to the first embodiment. [Figure 18] FIG. 18 is a schematic diagram illustrating an electronic circuit and a computing device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios may be different depending on the drawing. In this specification and in each drawing, elements similar to those previously described with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions thereof will be omitted where appropriate.

[0008] (First embodiment) FIG. 1 is a schematic plan view illustrating an electronic circuit according to the first embodiment. As shown in FIG. 1, an electronic circuit 110 according to the embodiment includes a first quantum bit 51B, a second quantum bit 52B, a first coupler 10A, a first conductive readout member 21, and a first filter 31F.

[0009] The first coupler 10A includes a first resonator 11R and a second resonator 12R. The first resonator 11R is capable of coupling to the first quantum bit 51B. The second resonator 12R is capable of coupling to the second quantum bit 52B. For example, the first resonator 11R is capable of electromagnetically coupling to the first quantum bit 51B. For example, the second resonator 12R is capable of electromagnetically coupling to the second quantum bit 52B. The electromagnetic coupling includes, for example, capacitive coupling. The electromagnetic coupling includes, for example, inductive coupling. The first coupler 10A is, for example, a tunable coupler.

[0010] The first filter 31F includes a first filter portion 31P, a first other filter portion 31Q, and a first readout portion 31R. The first filter portion 31P is capable of being coupled to the first resonator 11R. The first other filter portion 31Q is capable of being coupled to the second resonator 12R. The first readout portion 31R is capable of being coupled to the first readout conductive member 21. The first filter 31F may be, for example, a Purcell filter.

[0011] In this embodiment, the state of the quantum bit is read out via the first filter 31F by the first readout conductive member 21. This makes it possible to provide quantum bits and couplers with high density, for example.

[0012] For example, in the first reference example, the state of the quantum bit is read out via a readout resonator. In the first reference example, the readout resonator has a large area and requires space. This makes it difficult to provide multiple quantum bits at high density.

[0013] In contrast, in the embodiment, the resonator included in the first coupler 10A is coupled to the first filter 31F. The state of the quantum bit is read out via the coupler and the first filter 31F. In the embodiment, the readout resonator can be omitted. Space can be saved. High density quantum bits can be obtained. According to the embodiment, an electronic circuit capable of improving characteristics can be provided.

[0014] As shown in FIG. 1 , in this example, the first filter 31F includes a first conductive member 41 and a second conductive member 42. The first conductive member 41 includes a first conductive portion 41p and a first other conductive portion 41q. The second conductive member 42 includes a second conductive portion 42p and a second other conductive portion 42q. The first conductive portion 41p is capable of being coupled to the first resonator 11R. The second conductive portion 42p is capable of being coupled to the second resonator 12R. The first other conductive portion 41q is capable of being coupled to the first readout conductive member 21. The second other conductive portion 42q is capable of being coupled to the first readout conductive member 21.

[0015] The first conductive portion 41p corresponds to the first filter portion 31P. The second conductive portion 42p corresponds to the first other filter portion 31Q. At least one of the first other conductive portion 41q and the second other conductive portion 42q corresponds to the first read portion 31R.

[0016] First quantum bit 51B, second quantum bit 52B, first coupler 10A, first readout conductive member 21, and first filter 31F may be formed, for example, by a conductive layer 85 provided on first surface 81F of first substrate 81. As will be described later, at least a portion of conductive layer 85 may be provided, for example, on a plurality of different substrates.

[0017] 1, the first coupler 10A includes a first coupler Josephson junction 11K. One end of the first coupler Josephson junction 11K is connected to the first resonator 11R. The other end of the first coupler Josephson junction 11K is connected to the second resonator 12R.

[0018] The first resonator 11R includes a first inductor 11L. The second resonator 12R includes a second inductor 12L. In this example, a first resonator Josephson junction 11J is used as the first inductor 11L. In this example, a second resonator Josephson junction 12J is used as the second inductor 12L.

[0019] The first resonator 11R is, for example, a first transmon resonator, the second resonator 12R is, for example, a second transmon resonator, and the first coupler 10A is, for example, a double transmon coupler.

[0020] A first resonator conductive portion 11a is provided connected to the first inductor 11L (first resonator Josephson junction 11J). A second resonator conductive portion 12a is provided connected to the second inductor 12L (second resonator Josephson junction 12J).

[0021] The first filter portion 31P of the first filter 31F can be coupled to the first resonator conductive portion 11a. The first other filter portion 31Q of the first filter 31F can be coupled to the second resonator conductive portion 12a. The first resonator conductive portion 11a and the first inductor 11L (first resonator Josephson junction 11J) are included in the first resonator 11R. The second resonator conductive portion 12a and the second inductor 12L (second resonator Josephson junction 12J) are included in the second resonator 12R.

[0022] 1, the first quantum bit 51B includes a first bit Josephson junction 51J and a first bit conductive portion 51a. The first bit conductive portion 51a is connected to the first bit Josephson junction 51J. The second quantum bit 52B includes a second bit Josephson junction 52J and a second bit conductive portion 52a. The second bit conductive portion 52a is connected to the second bit Josephson junction 52J.

[0023] The first bit conductive portion 51a is capable of being coupled to the first resonator conductive portion 11a, and the second bit conductive portion 52a is capable of being coupled to the second resonator conductive portion 12a.

[0024] A ground conductive layer 85G may be provided by the conductive layer 85. The ground conductive layer 85G is set to a ground potential GND (e.g., a reference potential). For example, the ground conductive layer 85G may be provided around the conductive layer 85 that becomes the first quantum bit 51B, the second quantum bit 52B, the first coupler 10A, the first readout conductive member 21, and the first filter 31F.

[0025] As shown in FIG. 1 , a readout circuit 70R may be provided. For example, the readout circuit 70R may be included in the electronic circuit 110. The readout circuit 70R may be provided separately from the electronic circuit 110. The readout circuit 70R is electrically connected to the first readout conductive member 21. The readout circuit 70R can detect the state of the first quantum bit 51B and the state of the second quantum bit 52B based on a signal obtained from the first readout conductive member 21. For example, the readout circuit 70R detects an output signal based on an input signal input to the first readout conductive member 21. This makes it possible to detect the state of the first quantum bit 51B and the state of the second quantum bit 52B. The readout circuit 70R outputs an output signal Sig1 including the detection result.

[0026] FIG. 2 is a circuit diagram illustrating an electronic circuit according to the first embodiment. 2, the first resonator 11R includes a first inductor 11L and a first capacitor 11C. The first capacitor 11C is connected in parallel to the first inductor 11L. As already described, in this example, a first resonator Josephson junction 11J is provided as the first inductor 11L. The first capacitor 11C is connected in parallel to the first resonator Josephson junction 11J.

[0027] The second resonator 12R includes a second inductor 12L and a second capacitor 12C. The second capacitor 12C is connected in parallel to the second inductor 12L. As already described, in this example, a second resonator Josephson junction 12J is provided as the second inductor 12L. The second capacitor 12C is connected in parallel to the second resonator Josephson junction 12J.

[0028] The first coupler 10A further includes a first coupler Josephson junction 11K. One end of the first coupler Josephson junction 11K is connected to one end of the first inductor 11L and one end of the first capacitor 11C. The other end of the first coupler Josephson junction 11K is connected to one end of the second inductor 12L and one end of the second capacitor 12C.

[0029] The other end of the first inductor 11L and the other end of the first capacitor 11C are set to the ground potential GND. The other end of the second inductor 12L and the other end of the second capacitor 12C are set to the ground potential GND.

[0030] The first inductor 11L includes at least one first-resonator Josephson junction 11J. The first inductor 11L may include multiple first-resonator Josephson junctions 11J. The second inductor 12L includes at least one second-resonator Josephson junction 12J. The second inductor 12L may include multiple second-resonator Josephson junctions 12J.

[0031] The first quantum bit 51B includes a first-bit Josephson junction 51J and a first-bit capacitor 51C. The first-bit capacitor 51C is connected in parallel to the first-bit Josephson junction 51J. One end of the first-bit Josephson junction 51J and one end of the first-bit capacitor 51C are connected to the first-bit conductive portion 51a. The first-bit conductive portion 51a is connectable to the first resonator conductive portion 11a. The other end of the first-bit Josephson junction 51J and the other end of the first-bit capacitor 51C are set to the ground potential GND.

[0032] The second quantum bit 52B includes a second bit Josephson junction 52J and a second bit capacitor 52C. The second bit capacitor 52C is connected in parallel with the second bit Josephson junction 52J. One end of the second bit Josephson junction 52J and one end of the second bit capacitor 52C are connected to the second bit conductive portion 52a. The second bit conductive portion 52a is connectable to the second resonator conductive portion 12a. The other end of the second bit Josephson junction 52J and the other end of the second bit capacitor 52C are set to the ground potential GND.

[0033] The first bit conductive portion 51a and the first resonator conductive portion 11a may form a capacitance C1, and the second bit conductive portion 52a and the second resonator conductive portion 12a may form a capacitance C2.

[0034] The first conductive member 41 can be regarded as, for example, an LC circuit connected in parallel. The first conductive member 41 corresponds to, for example, a first filter resonator 41f. The second conductive member 42 can be regarded as, for example, an LC circuit connected in parallel. The second conductive member 42 corresponds to, for example, a second filter resonator 42f. These LC circuits are waveguide resonators.

[0035] In one example, the resonant frequency of the first quantum bit 51B is approximately 8.3 GHz. The resonant frequency of the second quantum bit 52B is approximately 9.0 GHz. The resonant frequency of the first resonator 11R is approximately 11.0 GHz. The resonant frequency of the second resonator 12R is approximately 11.7 GHz. The frequency of the first resonator 11R is different from the resonant frequency of the second resonator 12R. The resonant frequencies of the first resonator 11R and the second resonator 12R are read out via the first filter 31F. The resonant frequencies of the first quantum bit 51B and the second quantum bit 52B are substantially blocked by the first filter 31F.

[0036] In the embodiment, for example, the resonant frequency of first resonator 11R is higher than the resonant frequency of first quantum bit 51B, and the resonant frequency of second resonator 12R is higher than the resonant frequency of second quantum bit 52B.

[0037] 2, a loop 10LP is provided in the first coupler 10A. The loop 10LP includes a conductive path including a first coupler Josephson junction 11K, a conductive path including a first resonator Josephson junction 11J, and a conductive path including a second resonator Josephson junction 12J. For example, by controlling the magnetic flux Φ in the loop 10LP, the coupling strength between the first quantum bit 51B and the second quantum bit 52B can be controlled. The magnetic flux Φ in the loop 10LP may be controlled by a magnetic flux control unit 60, which will be described later.

[0038] For example, the coupling between the first quantum bit 51B and the second quantum bit 52B can be substantially turned off. This state is, for example, an idle state. In the idle state, the first resonator 11R can be considered as a resonator that is strongly coupled to the first quantum bit 51B. The first resonator 11R can function as a readout resonator. In this embodiment, a separately formed readout resonator is not required. A space-saving electronic circuit can be obtained.

[0039] For example, transmons are used instead of linear resonators as the first filter resonator 41f and the second filter resonator 42f. In this case, the transmon input is sufficiently weak. Strong coupling between the first resonator 11R and the first quantum bit 51B results in a large state-dependent frequency shift. For example, with strong coupling, the state-dependent frequency shift is approximately 30 MHz, making it possible to read out the quantum bit state.

[0040] For example, if there is a loss of about 50% in the output signal, a read error probability of less than 1% can be obtained for a read period of 200 ns.

[0041] FIG. 3 is a schematic view illustrating the characteristics of the electronic circuit according to the first embodiment. FIG. 3 illustrates the pass characteristics of the first filter 31F. The horizontal axis of FIG. 3 represents frequency fr1. The vertical axis represents pass ratio Tr. As already described, the first filter 31F may include a first filter resonator 41f and a second filter resonator 42f. FIG. 3 illustrates the pass characteristics of each of the first filter resonator 41f and the second filter resonator 42f. As shown in FIG. 3, the first filter 31F includes a pass band 50p, a first non-pass band 50r, and a second non-pass band 50s. The frequency fr1 of the pass band 50p is higher than the frequency fr1 of the first non-pass band 50r. The frequency fr1 of the pass band 50p is lower than the frequency fr1 of the second non-pass band 50s. The non-pass band (e.g., the first non-pass band 50r) corresponds to the reflection band of the first filter 31F. The passbands of the first filter resonator 41f and the second filter resonator 42f are included in the passband 50p.

[0042] 3 illustrates the resonant frequency f10A of the first coupler 10A. The resonant frequency f10A of the first coupler 10A includes the resonant frequency of the first resonator 11R and the resonant frequency of the second resonator 12R. The passband 50p of the first filter 31F includes the resonant frequency of the first resonator 11R and the resonant frequency of the second resonator 12R.

[0043] 3 illustrates an example of a quantum bit frequency f50. The quantum bit frequency f50 includes the resonant frequency of first quantum bit 51B and the resonant frequency of second quantum bit 52B. The reflection band of first filter 31F includes the quantum bit frequency f50 (the resonant frequency of first quantum bit 51B and the resonant frequency of second quantum bit 52B).

[0044] In the embodiment, the first filter 31F passes the resonant frequency of the first resonator 11R in an idle state. The first filter 31F does not substantially pass the resonant frequency of the first quantum bit 51B. Such a first filter 31F is coupled to the first readout conductive member 21. The first readout conductive member 21 functions as a readout line. In the embodiment, high-speed readout is possible. In the embodiment, a good quantum bit coherence time (high gate fidelity) is obtained.

[0045] In the embodiment, for example, the passband of the first filter 31F includes the resonant frequency of the first resonator 11R when the first coupling strength is substantially zero.

[0046] In one example, the absolute value of the difference between the resonant frequency of first resonator 11R and the resonant frequency of first quantum bit 51B may be greater than the absolute value of the difference between the resonant frequency of first resonator 11R and the resonant frequency of second resonator 12R. The absolute value of the difference between the resonant frequency of second resonator 12R and the resonant frequency of second quantum bit 52B may be greater than the absolute value of the difference between the resonant frequency of first resonator 11R and the resonant frequency of second resonator 12R.

[0047] In one example, the absolute value of the difference between the resonant frequency of the first quantum bit 51B and the resonant frequency of the second quantum bit 52B may be smaller than the absolute value of the difference between the resonant frequency of the first resonator 11R and the resonant frequency of the first quantum bit 51B. The absolute value of the difference between the resonant frequency of the first quantum bit 51B and the resonant frequency of the second quantum bit 52B may be smaller than the absolute value of the difference between the resonant frequency of the second resonator 12R and the resonant frequency of the second quantum bit 52B.

[0048] FIG. 4 is a schematic plan view illustrating the electronic circuit according to the first embodiment. 4, an electronic circuit 111 according to the embodiment includes a first quantum bit 51B, a second quantum bit 52B, a first coupler 10A, a first readout conductive member 21, and a first filter 31F. The configuration of the first filter 31F in the electronic circuit 111 is different from the configuration of the first filter 31F in the electronic circuit 110. Other configurations of the electronic circuit 111 may be similar to the configuration of the electronic circuit 110.

[0049] In the electronic circuit 111, the first filter 31F includes a first conductive member 41, a second conductive member 42, and at least one third conductive member 43. The third conductive member 43 is provided between the first conductive member 41 and the second conductive member 42. A plurality of third conductive members 43 may be provided. In this example, three third conductive members 43 are provided between the first conductive member 41 and the second conductive member 42. The third conductive member 43 can be coupled to the first conductive member 41 and the second conductive member 42.

[0050] The first conductive member 41 includes a first conductive portion 41p and a first other conductive portion 41q. The first conductive portion 41p is capable of being coupled to the first resonator 11R. The second conductive member 42 is capable of being coupled to the second resonator 12R. The first other conductive portion 41q is capable of being coupled to the first readout conductive member 21. The second conductive member 42 includes a second conductive portion 42p and a second other conductive portion 42q. The second conductive portion 42p is capable of being coupled to the second resonator 12R.

[0051] The first conductive portion 41p corresponds to the first filter portion 31P. The second conductive member 42 (second conductive portion 42p) corresponds to the first other filter portion 31Q. The first other conductive portion 41q corresponds to the first read portion 31R.

[0052] In the first filter 31F in the electronic circuit 111, the steepness of the change in the pass rate Tr between the pass band 50p and the non-pass band can be improved. For example, the read speed is improved. For example, performance is improved with respect to the coherence time of the quantum bit (high gate fidelity).

[0053] For example, the first filter 31F passes the resonant frequency of the first resonator 11R in an idle state and the resonant frequency of the second resonator 12R in an idle state. The first filter 31F does not substantially pass the quantum bit frequency over a wide band. A sharp bandpass filter is obtained.

[0054] FIG. 5 is a schematic plan view illustrating the electronic circuit according to the first embodiment. 5, an electronic circuit 112 according to the embodiment includes a first quantum bit 51B, a second quantum bit 52B, a first coupler 10A, a first conductive readout member 21, and a first filter 31F. The configuration of the first filter 31F in the electronic circuit 112 is different from the configuration of the first filter 31F in the electronic circuit 110. Other configurations of the electronic circuit 112 may be similar to the configuration of the electronic circuit 110.

[0055] In the electronic circuit 112, the first filter 31F includes a first conductive member 41, a second conductive member 42, and a third conductive member 43. The first conductive member 41 is capable of being coupled to the first resonator 11R. The second conductive member 42 is capable of being coupled to the second resonator 12R. The third conductive member 43 is capable of being coupled to the first readout conductive member 21. At least a portion of the third conductive member 43 is provided between the first conductive member 41 and the second conductive member 42.

[0056] For example, the first filter 31F includes a first conductive member Josephson junction 41J, a second conductive member Josephson junction 42J, and a third conductive member Josephson junction 43J. The first conductive member Josephson junction 41J is coupleable with the first conductive member 41. The second conductive member Josephson junction 42J is coupleable with the second conductive member 42. The third conductive member Josephson junction 43J is coupleable with the third conductive member 43.

[0057] The first filter 31F is based on, for example, a transmon resonator. In this embodiment, the first coupler 10A is a double transmon coupler. The transmon of the first coupler 10A functions as a readout resonator. By using the first filter 31F based on a transmon resonator, further space saving is possible.

[0058] FIG. 6 is a schematic plan view illustrating the electronic circuit according to the first embodiment. 6, in the electronic circuit 113 according to the embodiment, the configurations of the first conductive member 41 and the second conductive member 42 included in the first filter 31F are different from those in the electronic circuit 110. Other configurations of the electronic circuit 113 may be the same as those of the electronic circuit 110.

[0059] In the electronic circuit 113, the first conductive member 41 includes a plurality of first filter conductive portions (conductive portions 41a to 41c, etc.). The second conductive member 42 includes a plurality of second filter conductive portions (conductive portions 42a to 42c, etc.). The plurality of first filter conductive portions (conductive portions 41a to 41c) can be coupled to one another. The plurality of second filter conductive portions (conductive portions 42a to 42c, etc.) can be coupled to one another.

[0060] For example, a first conductive portion 41p is provided in one of the plurality of first filter conductive portions. For example, a first other conductive portion 41q is provided in another one of the plurality of first filter conductive portions. A second conductive portion 42p is provided in one of the plurality of second filter conductive portions. A second other conductive portion 42q is provided in another one of the plurality of second filter conductive portions.

[0061] 7(a) to 7(e) and 8(a) to 8(c) are schematic cross-sectional views illustrating a part of the electronic circuit according to the first embodiment. 7(a), in the first bit Josephson junction 51J, the conductive film 85a and the conductive film 85b face toward the first surface 81F of the first base 81. An insulating film 86a is provided between a part of the conductive film 85a and a part of the conductive film 85b.

[0062] 7(b), in the second bit Josephson junction 52J, the conductive film 85c and the conductive film 85d are directed onto the first surface 81F of the first base 81. An insulating film 86b is provided between a part of the conductive film 85c and a part of the conductive film 85d.

[0063] 7(c), in the first resonator Josephson junction 11J, the conductive films 85e and 85f face toward the first surface 81F of the first base 81. An insulating film 86c is provided between a part of the conductive film 85e and a part of the conductive film 85f.

[0064] 7(d), in the second resonator Josephson junction 12J, the conductive film 85g and the conductive film 85h are directed onto the first surface 81F of the first base 81. An insulating film 86d is provided between a part of the conductive film 85g and a part of the conductive film 85h.

[0065] 7(e), in the first coupler Josephson junction 11K, the conductive film 85i and the conductive film 85j are directed onto the first surface 81F of the first base 81. An insulating film 86e is provided between a part of the conductive film 85i and a part of the conductive film 85j.

[0066] 8(a), in the first conductive member Josephson junction 41J, the conductive film 85k and the conductive film 85l are directed onto the first surface 81F of the first base 81. An insulating film 86f is provided between a portion of the conductive film 85k and a portion of the conductive film 85l.

[0067] 8(b), in the second conductive member Josephson junction 42J, the conductive film 85m and the conductive film 85n are directed onto the first surface 81F of the first base 81. An insulating film 86g is provided between a portion of the conductive film 85m and a portion of the conductive film 85n.

[0068] 8(c), in the third conductive member Josephson junction 43J, the conductive film 85o and the conductive film 85p are directed onto the first surface 81F of the first base 81. An insulating film 86h is provided between a part of the conductive film 85o and a part of the conductive film 85p.

[0069] 9A and 9B are schematic cross-sectional views illustrating a part of the electronic circuit according to the first embodiment. 9(a), the first resonator conductive portion 11a may be provided on a first surface 81F of one substrate (e.g., the first substrate 81). The first conductive member 41 may be provided on a second surface 82F of another substrate (e.g., the second substrate 82). The second surface 82F faces the first surface 81F.

[0070] 9(b), the second resonator conductive portion 12a may be provided on a first surface 81F of one substrate (e.g., the first substrate 81), and the second conductive member 42 may be provided on a second surface 82F of another substrate (e.g., the second substrate 82).

[0071] 10A and 10B are schematic cross-sectional views illustrating a part of the electronic circuit according to the first embodiment. 10(a), the first conductive member 41 may be provided on one substrate. The first readout conductive member 21 may be provided on another substrate. The one substrate may be, for example, one of the first substrate 81 and the second substrate 82. The other substrate may be, for example, the other of the first substrate 81 and the second substrate 82.

[0072] 10(b), the second conductive member 42 may be provided on one substrate. The first readout conductive member 21 may be provided on another substrate. The one substrate may be, for example, one of the first substrate 81 and the second substrate 82. The other substrate may be, for example, the other of the first substrate 81 and the second substrate 82.

[0073] The first resonator conductive portion 11a may be provided on a first surface 81F of one base (e.g., the first base 81), and the first conductive member 41 may be provided on another surface (e.g., the back surface) of the base (e.g., the first base 81). The second resonator conductive portion 12a may be provided on the first surface 81F of one base (e.g., the first base 81), and the second conductive member 42 may be provided on another surface (e.g., the back surface) of the base (e.g., the first base 81).

[0074] The first conductive member 41 may be provided on one surface of a substrate, and the first readout conductive member 21 may be provided on another surface (e.g., the back surface) of the substrate. The second conductive member 42 may be provided on one surface of a substrate, and the first readout conductive member 21 may be provided on another surface (e.g., the back surface) of the substrate.

[0075] FIG. 11 is a schematic plan view illustrating the electronic circuit according to the first embodiment. As shown in FIG. 11, in an electronic circuit 114 according to the embodiment, a first coupler 10A can be coupled to a plurality of first readout conductive members 21 via a first filter 31F.

[0076] In the electronic circuit 114, the first filter 31F includes a plurality of first conductive members 41 and a plurality of second conductive members 42. The plurality of first conductive members 41 are connectable to each other. The plurality of second conductive members 42 are connectable to each other. A portion of one of the plurality of first conductive members 41 corresponds to the first conductive portion 41p. A portion of another one of the plurality of first conductive members 41 corresponds to the first other conductive portion 41q. A portion of one of the plurality of second conductive members 42 corresponds to the second conductive portion 42p. A portion of another one of the plurality of second conductive members 42 corresponds to the second other conductive portion 42q.

[0077] A portion (e.g., an end) of each of the plurality of first conductive members 41 and a portion (e.g., an end) of each of the plurality of second conductive members 42 are connected to the ground conductive layer 85G. In this example, a portion of each of the plurality of first conductive members 41 and a portion of each of the plurality of second conductive members 42 are connected to a conductive layer 85 (ground conductive layer 85G) provided around these conductive members. A portion of each of the plurality of first conductive members 41 and a portion of the plurality of second conductive members 42 may be electrically connected to a conductive layer 88 (see FIG. 13 ) provided on the back surface of the first base 81 by a through-connection portion provided in the first base 81. The conductive layer 88 functions as the ground conductive layer 85G.

[0078] Thus, the first filter 31F may include a plurality of conductive members. When the plurality of conductive members includes one first conductive member 41 and one second conductive member 42, the number of conductive members n is 2. When the plurality of conductive members includes one first conductive member 41, one second conductive member 42, and one third conductive member 43, the number of conductive members n is 3. In the electronic circuit 114, the number of conductive members n is 4.

[0079] FIG. 12 is a schematic plan view illustrating the electronic circuit according to the first embodiment. 12, in an electronic circuit 115 according to the embodiment, a first coupler 10A is capable of being coupled to a plurality of first readout conductive members 21 via a first filter 31F. The first filter 31F includes a first conductive member 41, a second conductive member 42, and a third conductive member 43. The first conductive member 41 faces a portion of the third conductive member 43. The first conductive member 41 is capable of being coupled to a portion of the third conductive member 43. The second conductive member 42 corresponds to another portion of the third conductive member 43. The second conductive member 42 is capable of being coupled to another portion of the third conductive member 43. The electronic circuits 114 and 115 can also be provided with improved characteristics.

[0080] In the electronic circuit 115, a portion (e.g., an end portion) of each of the first conductive member 41, the second conductive member 42, and the third conductive member 43 is connected to the ground conductive layer 85G. In this example, a portion of each of the first conductive member 41, the second conductive member 42, and the third conductive member 43 is connected to a conductive layer 85 (ground conductive layer 85G) provided around these conductive members. A portion of each of the first conductive member 41, the second conductive member 42, and the third conductive member 43 may be electrically connected to a conductive layer 88 (see FIG. 13) provided on the back surface of the first base 81 by a through-connection portion. The conductive layer 88 functions as the ground conductive layer 85G.

[0081] An example of the simulation results of the characteristics of the electronic circuit 114 and the electronic circuit 115 will be described below. FIG. 13 is a schematic cross-sectional view illustrating the electronic circuit according to the first embodiment. FIG. 13 illustrates a simulation model. As shown in FIG. 13, a conductive layer 85 and a conductive layer 87 are provided on a first surface 81F of a first substrate 81. The conductive layer 87 corresponds to the first conductive member 41, the second conductive member 42, or the third conductive member 43. A conductive layer 88 is provided on the rear surface of the first substrate 81. In the simulation, the first substrate 81 has a dielectric constant of silicon. The thickness of the first substrate 81 is 300 μm. The width w1 (length in a direction intersecting the extending direction) of the conductive layer 87 is 20 μm. The distances w2 and w3 between the conductive layer 85 and the conductive layer 87 are 10 μm. In the simulation, for simplicity, the thicknesses of the conductive layers 85, 87, and 88 are set to 0.

[0082] FIG. 14 is a graph illustrating the characteristics of the electronic circuit according to the first embodiment. Fig. 14 illustrates the pass characteristics of the first filter 31 in the pattern of the electronic circuit 114. The horizontal axis of Fig. 14 represents frequency, and the vertical axis represents insertion loss S21. Fig. 14 shows examples where the number n of multiple conductive members included in the first filter 31F is 2, 3, and 4.

[0083] 14, good transmission characteristics are obtained in the electronic circuit 114. As the number n of the plurality of conductive members increases, a low insertion loss S21 is obtained.

[0084] FIG. 15 is a graph illustrating the characteristics of the electronic circuit according to the first embodiment. FIG. 15 illustrates the pass characteristics of the first filter 31 in the pattern of the electronic circuit 115. FIG. 15 shows the characteristics when the number n of multiple conductive members in the electronic circuit 114 illustrated in FIG. 14 is 3. The horizontal axis of FIG. 15 represents frequency. The vertical axis represents insertion loss S21. As shown in FIG. 15, the electronic circuit 115 provides a frequency band in which the insertion loss S2 is significantly low. This frequency band corresponds to the resonant frequency of the quantum bit. The electronic circuit 115 provides better cutoff and pass characteristics. Stable readout operations can be performed.

[0085] FIG. 16 is a schematic view illustrating the electronic circuit according to the first embodiment. 16 , an electronic circuit 120 according to an embodiment includes a first quantum bit 51B, a second quantum bit 52B, a first coupler 10A, a first conductive readout member 21, and a first filter 31F. The electronic circuit 120 further includes a third quantum bit 53B, a second coupler 10B, a second filter 32F, and a second conductive readout member 22. Except for these, the configuration of the electronic circuit 120 may be similar to the configuration of the electronic circuit 110.

[0086] The second coupler 10B includes a third resonator 13R that can be coupled to the second quantum bit 52B and a fourth resonator 14R that can be coupled to the third quantum bit 53B. The second filter 32F includes a second filter portion 32P, a second other filter portion 32Q, and a second readout portion 32R. The second filter portion 32P can be coupled to the third resonator 13R. The second other filter portion 32Q can be coupled to the fourth resonator 14R. The second readout portion 32R can be coupled to the second readout conductive member 22. For example, the readout circuit 70R can be electrically connected to the second readout conductive member 22.

[0087] In electronic circuit 120, the state of second qubit 52B may be read out via second coupler 10B and second filter 32F. The state of third qubit 53B may be read out via second coupler 10B and second filter 32F. Space savings are possible.

[0088] The configuration of the first filter 31F described in relation to the electronic circuit 111 and the electronic circuit 112 may be applied to the second filter 32F.

[0089] FIG. 17 is a schematic view illustrating the electronic circuit according to the first embodiment. 17, the electronic circuit 121 according to the embodiment further includes a fourth quantum bit 54B, a third coupler 10C, a third filter 33F, and a third readout conductive member 23. Except for these, the configuration of the electronic circuit 121 may be similar to the configuration of the electronic circuit 120.

[0090] The third coupler 10C includes a fifth resonator 15R that can be coupled to the second quantum bit 52B and a sixth resonator 16R that can be coupled to the fourth quantum bit 54B. The third filter 33F includes a third filter portion 33P, a third other filter portion 33Q, and a third readout portion 33R. The third filter portion 33P can be coupled to the fifth resonator 15R. The third other filter portion 33Q can be coupled to the sixth resonator 16R. The third readout portion 33R can be coupled to the third readout conductive member 23. For example, the readout circuit 70R can be electrically connected to the third readout conductive member 23.

[0091] In electronic circuit 121, the state of second qubit 52B may be read out via third coupler 10C and third filter 33F. The state of fourth qubit 54B may be read out via third coupler 10C and third filter 33F. Space savings are possible.

[0092] In the electronic circuits 120 and 121, "Q" corresponds to a quantum bit. "T" corresponds to a transmon. "T" corresponds to a filter (such as a Purcell filter).

[0093] In electronic circuit 121, the state of second qubit 52B can be read out by a first set of circuits, a second set of circuits, and a third set of circuits. The first set of circuits includes a first coupler 10A and a first filter 31F. The second set of circuits includes a second coupler 10B and a second filter 32F. The third set of circuits includes a third coupler 10C and a third filter 33F. The readout operation via the three sets of circuits allows the state of the qubit to be determined based on a "majority vote."

[0094] 17, for example, a signal processing unit 70P may be provided. The signal processing unit 70P may be included in the electronic circuit 121. The signal processing unit 70P may be provided separately from the electronic circuit 121.

[0095] The signal processing unit 70P can obtain a first readout signal Sr1, a second readout signal Sr2, and a third readout signal Sr3. The first readout signal Sr1 is obtained from the first readout conductive member 21. The second readout signal Sr2 is obtained from the second readout conductive member 22. The third readout signal Sr3 is obtained from the third readout conductive member 23.

[0096] The signal processor 70P can compare the first read value V1 related to the first read signal Sr1, the second read value V2 related to the second read signal Sr2, and the third read value V3 related to the third read signal Sr3. The signal processor 70P can output a value Sig2 from among the first read value V1, the second read value V2, and the third read value V3 that has the smallest difference from the others. For example, a more accurate determination can be made by determining by majority vote.

[0097] (Second embodiment) FIG. 18 is a schematic diagram illustrating an electronic circuit and a computing device according to the second embodiment. 18, the electronic circuit 130 according to the embodiment includes a magnetic flux control unit 60. The configuration of the electronic circuit 130 other than this may have any of the configurations of the electronic circuit described in relation to the first embodiment.

[0098] The magnetic flux control unit 60 can control the magnetic flux Φ in the space within the loop 10LP. As already described, the loop 10LP includes a conductive path including the first coupler Josephson junction 11K, a conductive path including the first resonator Josephson junction 11J, and a conductive path including the second resonator Josephson junction 12J.

[0099] In this example, the magnetic flux control unit 60 includes a first control conductive unit 61. For example, a control unit 70 may be provided. The control unit 70 controls the magnetic flux Φ in the loop 10LP, for example, by controlling the magnetic flux control unit 60. The control unit 70 supplies a magnetic flux control signal Sc to the first control conductive unit 61, for example. As a result, the control unit 70 controls the magnetic flux Φ in the loop 10LP. A computing device 210 according to the embodiment includes an electronic circuit 130 and the control unit 70.

[0100] The control unit 70 is capable of performing at least a first operation and a second operation. In the first operation, the control unit 70 is capable of varying the magnetic flux Φ in the space within the loop 10LP between a first value and a second value. The second value is different from the first value. The control unit 70 performs two-qubit operation on the first quantum bit 51B and the second quantum bit 52B by varying the magnetic flux Φ. In the second operation, the control unit 70 performs two-qubit operation on the first quantum bit 51B and the second quantum bit 52B by modulating the magnetic flux Φ with an AC current.

[0101] Electronic circuit 130 may include a first quantum bit control unit 65A and a second quantum bit control unit 65B. Control unit 70 can supply a first quantum bit control signal Sb1 to first quantum bit control unit 65A. Control unit 70 can supply a second quantum bit control signal Sb2 to second quantum bit control unit 65B. By controlling these signals, the state of the quantum bit can be controlled.

[0102] The embodiment may include the following configurations (e.g., technical solutions). (Configuration 1) a first qubit; and a second qubit; and a first coupler including a first resonator and a second resonator, the first resonator being couplable with the first quantum bit and the second resonator being couplable with the second quantum bit; a first readout conductive member; a first filter including a first filter portion, a first other filter portion, and a first readout portion, wherein the first filter portion is couplable with the first resonator, the first other filter portion is couplable with the second resonator, and the first readout portion is couplable with the first readout conductive member; An electronic circuit comprising:

[0103] (Configuration 2) The first filter is a first conductive member including a first conductive portion and a first other conductive portion; a second conductive member including a second conductive portion and a second other conductive portion; Including, the first conductive portion is couplable with the first resonator; the second conductive portion is coupleable to the second resonator; the first other conductive portion is connectable to the first readout conductive member; 2. The electronic circuit of claim 1, wherein the second other conductive portion is coupleable with the first readout conductive member.

[0104] (Configuration 3) The first filter is a first conductive member including a first conductive portion and a first other conductive portion; A second conductive member; at least one third conductive member provided between the first conductive member and the second conductive member; Including, the third conductive member is connectable to the first conductive member and the second conductive member; the first conductive portion is couplable with the first resonator; the second conductive member is capable of being coupled to the second resonator; 2. The electronic circuit of claim 1, wherein the first other conductive portion is connectable to the first readout conductive member.

[0105] (Configuration 4) The first filter is a first conductive member that is coupleable with the first resonator; a second conductive member that is coupleable with the second resonator; a third conductive member coupleable with the first readout conductive member, at least a portion of the third conductive member being disposed between the first conductive member and the second conductive member; 2. The electronic circuit of claim 1,

[0106] (Configuration 5) The first filter is a first conductive member Josephson junction coupleable with the first conductive member; a second conductive member Josephson junction coupleable with the second conductive member; a third conductive member Josephson junction coupleable with the third conductive member; 5. The electronic circuit of claim 4, further comprising:

[0107] (Configuration 6) the resonant frequency of the first resonator is higher than the resonant frequency of the first quantum bit; the resonant frequency of the second resonator is higher than the resonant frequency of the second quantum bit; an absolute value of a difference between the resonant frequency of the first resonator and the resonant frequency of the first quantum bit is greater than an absolute value of a difference between the resonant frequency of the first resonator and the resonant frequency of the second resonator; The electronic circuit of any one of configurations 1 to 5, wherein the absolute value of the difference between the resonant frequency of the second resonator and the resonant frequency of the second quantum bit is greater than the absolute value of the difference between the resonant frequency of the first resonator and the resonant frequency of the second resonator.

[0108] (Configuration 7) 7. The electronic circuit of claim 6, wherein an absolute value of a difference between the resonant frequency of the first quantum bit and the resonant frequency of the second quantum bit is smaller than the absolute value of the difference between the resonant frequency of the first resonator and the resonant frequency of the first quantum bit, and is smaller than the absolute value of the difference between the resonant frequency of the second resonator and the resonant frequency of the second quantum bit.

[0109] (Configuration 8) the first resonator includes a first inductor and a first capacitor connected in parallel with the first inductor; the second resonator includes a second inductor and a second capacitor connected in parallel with the second inductor; the first coupler further includes a first coupler Josephson junction; one end of the first coupler Josephson junction is connected to one end of the first inductor and one end of the first capacitor; 6. The electronic circuit according to any one of configurations 1 to 5, wherein the other end of the first coupler Josephson junction is connected to one end of the second inductor and one end of the second capacitor.

[0110] (Configuration 9) the first inductor includes at least one first resonator Josephson junction; 9. The electronic circuit of configuration 8, wherein the second inductor includes at least one second resonator Josephson junction.

[0111] (Configuration 10) 10. The electronic circuit of claim 9, wherein the coupling strength between the first quantum bit and the second quantum bit is controllable by controlling a magnetic flux in a loop including a conductive path including the first coupler Josephson junction, a conductive path including the first resonator Josephson junction, and a conductive path including the second resonator Josephson junction.

[0112] (Configuration 11) 11. The electronic circuit of claim 10, wherein the passband of the first filter includes a resonant frequency of a first resonator when the first coupling strength is substantially zero and a resonant frequency of a second resonator when the second coupling strength is substantially zero.

[0113] (Configuration 12) 12. The electronic circuit of claim 11, wherein the reflection band of the first filter includes a resonant frequency of the first quantum bit and a resonant frequency of the second quantum bit.

[0114] (Configuration 13) a readout circuit electrically connected to the first readout conductive member; 13. The electronic circuit of claim 12, wherein the readout circuit detects an output signal based on an input signal input to the first readout conductive member, and is capable of detecting the state of the first quantum bit and the state of the second quantum bit.

[0115] (Configuration 14) The third qubit, A second coupler; A second filter; a second readout conductive member; Furthermore, The second coupler is a third resonator coupleable to the second quantum bit; a fourth resonator coupleable with the third quantum bit; Including, the second filter includes a second filter portion, a second other filter portion, and a second readout portion; the second filter section is coupleable to the third resonator; the second other filter portion is capable of being coupled to the fourth resonator; 13. The electronic circuit of any one of configurations 1 to 12, wherein the second readout portion is connectable to the second readout conductive member.

[0116] (Configuration 15) The fourth qubit, A third coupler; A third filter; a third readout conductive member; Furthermore, The third coupler is a fifth resonator coupleable to the second quantum bit; a sixth resonator coupleable with the fourth quantum bit; Including, the third filter includes a third filter portion, a third other filter portion, and a third readout portion; the third filter section is coupleable to the fifth resonator; the third other filter portion is capable of being coupled to the sixth resonator; 15. The electronic circuit of claim 14, wherein the third readout portion is coupleable to the third readout conductive member.

[0117] (Configuration 16) further comprising a signal processing unit; the signal processing unit is capable of acquiring a first readout signal obtained from the first readout conductive member, a second readout signal obtained from the second readout conductive member, and a third readout signal obtained from the third readout conductive member; The electronic circuit of configuration 15, wherein the signal processing unit is capable of comparing a first readout value related to a first readout signal, a second readout value related to a second readout signal, and a third readout value related to a third readout signal, and outputting a value among the first readout value, the second readout value, and the third readout value that is smaller in difference from the others.

[0118] (Configuration 17) 12. The electronic circuit according to any one of configurations 10 to 11, further comprising a magnetic flux control unit capable of controlling the magnetic flux in the space within the loop.

[0119] (Configuration 18) 18. The electronic circuit according to claim 17; A control unit; Equipped with the magnetic flux control unit includes a first control conductive unit, The control unit is capable of providing a flux control signal to the first control conductive unit.

[0120] (Configuration 19) The control unit is capable of performing at least a first operation and a second operation, In the first operation, the control unit performs two-qubit operation on the first quantum bit and the second quantum bit by changing the magnetic flux between a first value and a second value different from the first value; 19. The computing device of claim 18, wherein in the second operation, the control unit performs the two-qubit operation on the first qubit and the second qubit by modulating the magnetic flux with an alternating current.

[0121] According to the embodiment, it is possible to provide an electronic circuit and a computing device that can improve the performance.

[0122] The embodiments of the present invention have been described above with reference to examples. However, the present invention is not limited to these examples. For example, the specific configurations of elements such as nonlinear elements, Josephson junctions, capacitors, and conductive members included in electronic circuits or computing devices are within the scope of the present invention as long as a person skilled in the art can implement the present invention in a similar manner and obtain similar effects by appropriately selecting them from known ranges.

[0123] Any combination of two or more elements of each example within the scope of technical feasibility is also included within the scope of the present invention as long as it encompasses the gist of the present invention.

[0124] All electronic circuits and computing devices that can be implemented by a person skilled in the art by appropriately modifying the design based on the electronic circuits and computing devices described above as embodiments of the present invention also fall within the scope of the present invention, as long as they include the gist of the present invention.

[0125] Within the scope of the concept of the present invention, a person skilled in the art may conceive of various modifications and alterations, and it is understood that these modifications and alterations also fall within the scope of the present invention.

[0126] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0127] 10A~10B...1st to 3rd couplers, 10LP...Loop, 11C, 12C...1st and 2nd capacitors, 11J, 12J...1st and 2nd resonator Josephson junction, 11K...first coupler Josephson junction, 11L, 12L...First and second inductors, 11R~16R...1st~6th resonator, 11a, 12a...first and second resonator conductive parts, 21 to 23: first to third read conductive members, 31F~33F...1st to 3rd filters, 31P~33P...1st to 3rd filter parts, 31Q~33Q...1st to 3rd other filter parts, 31R to 33R: 1st to 3rd readout parts, 41 to 43...first to third conductive members, 41f, 42f...first and second filter resonators, 41J to 43J...first to third conductive member Josephson junctions, 41p, 42p...first and second conductive parts, 41q, 42q...first and second other conductive parts, 50p...passband, 50r, 50s... 1st and 2nd non-pass bands, 51B~54...1st to 4th quantum bits, 51C, 52C... 1st and 2nd bit capacitors, 51J, 52J... 1st and 2nd bit Josephson junctions, 51a, 52a...first and second bit conductive portions, 60...magnetic flux control unit, 61...control conductive portion, 65A, 65B...first and second quantum bit control units, 70...control unit, 70P: Signal processing section, 70R...readout circuit, 81, 82...first and second bases, 81F, 82F...1st and 2nd floors, 85...conductive layer, 85G: Ground conductive layer, 85a~85p...conductive film, 86a to 86h...insulating film, 87...conductive layer, 88...conductive layer, Φ...Magnetic flux, 110~112, 120, 121, 130...electronic circuit, 210...computing device, C1~C6...capacitance, GND: Ground potential, Sb1, Sb2...first and second quantum bit control signals, Sig1: Output signal, SIg2...value, Sr1 to Sr3: first to third read signals, Tr...passage rate, V1 to V3: 1st to 3rd readout values, f10A…resonance frequency, f50...frequency, fr1...frequency

Claims

1. a first qubit; and a second qubit; and a first coupler including a first resonator and a second resonator, the first resonator being electromagnetically couplable with the first quantum bit and the second resonator being electromagnetically couplable with the second quantum bit; a first readout conductive member; a first filter including a first filter portion, a first other filter portion, and a first readout portion, wherein the first filter portion is capacitively coupled to the first resonator, the first other filter portion is capacitively coupled to the second resonator, and the first readout portion is capacitively coupled to the first readout conductive member; Equipped with the electromagnetic coupling includes capacitive coupling or inductive coupling; the first coupler further includes a first coupler Josephson junction; one end of the first coupler Josephson junction is connected to the first resonator; The other end of the first coupler Josephson junction is connected to the second resonator.

2. The first filter is a first conductive member including a first conductive portion and a first other conductive portion; a second conductive member including a second conductive portion and a second other conductive portion; Including, the first conductive portion is capable of capacitively coupling to the first resonator; the second conductive portion is capable of capacitively coupling to the second resonator; the first other conductive portion is capable of capacitive coupling with the first readout conductive member; The electronic circuit according to claim 1 , wherein the second other conductive portion is capable of being capacitively coupled to the first readout conductive member.

3. The first filter is a first conductive member including a first conductive portion and a first other conductive portion; A second conductive member; at least one third conductive member provided between the first conductive member and the second conductive member; Including, the third conductive member is capable of capacitively coupling with the first conductive member and the second conductive member; the first conductive portion is capable of capacitively coupling to the first resonator; the second conductive member is capable of capacitively coupling with the second resonator, The electronic circuit according to claim 1 , wherein the first other conductive portion is capable of being capacitively coupled to the first readout conductive member.

4. The first filter is a first conductive member capable of being capacitively coupled to the first resonator; a second conductive member capable of capacitively coupling with the second resonator; a third conductive member capable of capacitively coupling with the first readout conductive member, at least a portion of the third conductive member being provided between the first conductive member and the second conductive member; 10. The electronic circuit of claim 1, comprising:

5. The first filter is a first conductive member Josephson junction capable of capacitively coupling with the first conductive member; a second conductive member Josephson junction capable of capacitively coupling with the second conductive member; a third conductive member Josephson junction capable of capacitively coupling with the third conductive member; The electronic circuit of claim 4 further comprising:

6. the first resonator includes a first inductor and a first capacitor connected in parallel with the first inductor; the second resonator includes a second inductor and a second capacitor connected in parallel with the second inductor; the one end of the first coupler Josephson junction is connected to one end of the first inductor and one end of the first capacitor; the other end of the first coupler Josephson junction is connected to one end of the second inductor and one end of the second capacitor; the first inductor includes at least one first resonator Josephson junction; The electronic circuit of claim 1 , wherein the second inductor includes at least one second resonator Josephson junction.

7. 7. The electronic circuit of claim 6, wherein a coupling strength between the first quantum bit and the second quantum bit is controllable by controlling a magnetic flux in a loop including a conductive path including the first coupler Josephson junction, a conductive path including the first resonator Josephson junction, and a conductive path including the second resonator Josephson junction.

8. a third qubit; and A second coupler; A second filter; a second readout conductive member; Furthermore, The second coupler is a third resonator capable of capacitively coupling to the second quantum bit; a fourth resonator capable of capacitively coupling to the third quantum bit; Including, the second filter includes a second filter portion, a second other filter portion, and a second readout portion; the second filter section is capable of being capacitively coupled to the third resonator; the second other filter portion is capable of being capacitively coupled to the fourth resonator, the second readout portion is capable of capacitively coupling with the second readout conductive member; a fourth qubit; and A third coupler; A third filter; and a third readout conductive member; Furthermore, The third coupler is a fifth resonator capable of capacitively coupling to the second quantum bit; a sixth resonator capable of capacitively coupling to the fourth quantum bit; Including, the third filter includes a third filter portion, a third other filter portion, and a third readout portion; the third filter section is capable of being capacitively coupled to the fifth resonator; the third other filter portion is capable of being capacitively coupled to the sixth resonator, The electronic circuit according to claim 1 , wherein the third readout portion is capable of being capacitively coupled to the third readout conductive member.

9. The electronic circuit according to claim 7 , further comprising a magnetic flux control unit capable of controlling the magnetic flux in the space within the loop.

10. an electronic circuit according to claim 9; A control unit; Equipped with the magnetic flux control unit includes a first control conductive unit, The controller is capable of providing a flux control signal to the first control conductive section.

Images