Multiplexing of cavity-induced phase gate drive signals

Abstract

Techniques related to quantum gate coupling are provided. For example, one or more embodiments described herein may include a method for driving multiple resonator-induced phase gates from the same signal control line. The method may include controlling the quantum gate coupling through a quantum circuit by filtering a resonator-induced phase gate signal from a signal control line multiplexed with the multiple resonator-induced phase gate signals.

Description

Technical Field

[0001] The present disclosure relates to multiplexing signals for driving resonator-induced phase (RIP) gates, and more particularly to frequency multiplexing a plurality of RIP gate signals onto control lines of a quantum circuit.

Summary of the Invention

[0002] The following presents a summary in order to provide a basic understanding of one or more embodiments of the invention. This summary is not intended to identify key or critical elements, nor to delineate any scope of particular embodiments or any scope of the claims. Its sole purpose is to present concepts in a simplified form as a prelude to the more detailed description that is presented later. In one or more embodiments described herein, systems, methods, or apparatus or combinations thereof related to multiplexing RIP gate signals are described.

[0003] According to one embodiment, a method is provided. The method may include controlling quantum gate coupling via a quantum circuit by filtering resonator-induced phase gate signals from a plurality of resonator-induced phase gate signals and a multiplexed signal control line.

[0004] According to another embodiment, a method is provided. The method may include routing a signal control line to a filter resonator via a quantum circuit. A plurality of resonator-induced phase gate signals may be multiplexed onto the signal control line. The method may also include coupling an output of the filter resonator to a resonator-induced phase gate via the quantum circuit.

[0005] According to one embodiment, a system is provided. The system may include a resonator bus coupled to a filter resonator. The filter resonator may output a control tone for driving the resonator bus from a plurality of control tones multiplexed onto a quantum gate control line.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0016] The following detailed description is merely exemplary in nature and is not intended to limit embodiments, or the application or use of embodiments, or both. Further, it is not intended to be constrained by any of the expressions or suggested information presented in the background section, or the summary section, or the detailed description section of the invention above.

[0017] Here, one or more embodiments are described with reference to the drawings, and throughout, like reference numerals are used to refer to like elements. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a more thorough understanding of one or more embodiments. However, in various instances, it will be apparent that one or more embodiments may be practiced without these specific details.

[0018] The RIP gate is one way to generate quantum logic gates between qubits in a quantum circuit. Conventionally, to control an RIP gate, at least one drive line is required for each qubit pair. As a result, controlling quantum coupling using RIP gates can be limited by the number of drive lines required. For example, as the number of qubits included in a quantum circuit increases, the number of required drive lines can also increase. Thereby, the increase in drive lines can require an increase in the size of the quantum circuit since it can have an undesirable effect of arranging drive lines at least in proximity to each other in the quantum circuit.

[0019] Various embodiments described herein can include a method, system, or apparatus, or a combination thereof, for controlling quantum gate coupling using a plurality of RIP gates driven from the same control line. One or more embodiments described herein can relate to a quantum circuit that couples various qubits via one or more RIP gates. Further, one or more RIP gates can be driven by RIP gate signals multiplexed onto a common control line. In various embodiments, each RIP gate can be coupled to the control line via a filter resonator and a capacitor. The filter resonator can filter the drive signal for the RIP gate from the multiplexed control signal of the control line. Further, the bandwidth of the filter resonator can be tuned by adjusting the coupling capacitance established by the capacitor. Thereby, the drive line layout can be condensed and crosstalk between RIP gates can be reduced to an acceptable level compatible with 99.99% fidelity gates. In addition, the relaxation time of the Purcell effect can be extended by the filter resonator. Further, the thermal photon number of the RIP gate can be reduced by a cold on-chip filter resonator.

[0020] The RIP gate is a form of quantum logic gate that can couple superconducting qubits. The RIP gate can be a full microwave multi-qubit entanglement gate that can enable a high degree of flexibility at qubit frequencies. The RIP gate can operate by coupling two or more fixed-frequency qubits to a resonator bus. By adiabatically applying and removing an off-resonance pulse to the resonator bus, the system can experience a closed loop in phase space, after which the resonator bus can remain unchanged while the qubits acquire a state-dependent phase. In various embodiments, the RIP gate can be utilized to control qubit coupling in circuit quantum electrodynamics ("circuit QED").

[0021] As described herein, the term "superconducting" can characterize materials such as aluminum (e.g., superconducting critical temperature of 1.2 Kelvin) or niobium (e.g., superconducting critical temperature of 9.3 Kelvin) that exhibit superconducting properties at or below the superconducting critical temperature. Additionally, one of ordinary skill in the art will recognize that other superconductor materials (e.g., hydride superconductors such as lithium / magnesium hydride alloys) can be used in the various embodiments described herein.

[0022] FIG. 1 shows an exemplary and non-limiting quantum circuit layout 100 that may illustrate the coupling of a plurality of RIP gates 102 to a common signal control line 104 according to one or more embodiments described herein. Repeated descriptions of similar elements utilized in other embodiments described herein are omitted for brevity. As shown in FIG. 1, a plurality of “N” RIP gates 102 may be coupled to the same signal control line 104, where “N” is a positive integer. For example, the plurality of RIP gates 102 coupled to the signal control line 104 may include, but are not limited to, a first RIP gate 102a, a second RIP gate 102b, and one or more additional RIP gates 102 up to a “Nth” RIP gate 102n (e.g., “N” is an integer greater than 2). In various embodiments, the number of RIP gates 102 coupled to the same signal control line 104 may be, for example, 1 or more and 100 or less. In various embodiments, each RIP gate 102 may couple two or more superconducting qubits (e.g., as further described herein).

[0023] The RIP gate 102 can be coupled to a common signal control line 104 via a plurality of filter resonators 106 and capacitors 108. As shown in FIG. 1, each of the RIP gates 102 can be coupled to a respective filter resonator 106 via a drive line 110. In various embodiments, the drive line 110 can be a superconducting resonator line. For example, the first RIP gate 102a can be coupled to the first filter resonator 106a, and the second RIP gate 102b can be coupled to the second filter resonator 106b. When the quantum circuit layout 100 includes "N" RIP gates 102, the "N"th RIP gate 102n can be coupled to the "N"th filter resonator 106n. In various embodiments, the filter resonator 106 can be a band-pass filter resonator, a band-stop filter resonator, or a combination thereof. Exemplary types of filtering that can be utilized as the filter resonator 106 include, but are not limited to, coplanar waveguides, cavity band-pass or cavity band-stop filters, or lumped elements, or a combination thereof, etc. In one or more embodiments, one or more of the filter resonators 106 can be a band-pass filter (e.g., a passive or active band-pass filter) derived from a cascaded high-pass and low-pass filter (e.g., a passive or active high-pass and low-pass filter). In one or more embodiments, one or more of the filter resonators 106 can be a band-stop filter (e.g., a passive or active band-stop filter) derived from a cascaded high-pass and low-pass filter (e.g., a passive or active high-pass and low-pass filter) coupled to a summing circuit.

[0024] The filter resonator 106 can be further coupled to the signal control line 104 via a capacitor 108. As shown in FIG. 1, each of the filter resonators 106 can be coupled to a respective capacitor 108. For example, the first filter resonator 106a can be coupled to the first capacitor 108a, and the second filter resonator 106b can be coupled to the second capacitor 108b. When the quantum circuit layout 100 includes "N" RIP gates 102, the "N"th filter resonator 106n can be coupled to the "N"th capacitor 108n. In various embodiments, the capacitor 108 can control the coupling capacitance between the signal control line 104 and the filter resonator 106. Further, the coupling capacitance established by the capacitor 108 can affect the bandwidth of the filter resonator 106. For example, the bandwidth of the first filter resonator 106a can be adjusted by setting the capacitance of the first capacitor 108a. Similarly, the bandwidth of the second filter resonator 106b can be adjusted by setting the capacitance of the second capacitor 108b. When the quantum circuit layout 100 includes "N" RIP gates 102, the bandwidth of the "N"th filter resonator 106n can be adjusted by setting the capacitance of the "N"th capacitor 108n.

[0025] As shown in FIG. 1, the signal control line 104 can be further coupled to one or more quantum controllers 112. The one or more quantum controllers 112 can control the stimulation of various qubits coupled to the RIP gate 102. For example, the quantum controller 112 can control one or more signals carried by the signal control line 104. In various embodiments, the one or more quantum controllers 112 can include one or more multiplexers 114 that can frequency-division multiplex a plurality of RIP gate signals onto the signal control line 104 to control the plurality of RIP gates 102 coupled to the signal control line 104.

[0026] As further described herein, a plurality of RIP gate signals may be frequency multiplexed onto the signal control line 104 by a quantum controller 112 (e.g., multiplexer 114). Each RIP gate 102 may be driven by a respective RIP gate signal from the plurality of multiplexed signals. Further, the filter resonator 106 may filter out each RIP gate signal from the multiplexed signals based on frequency. For example, the coupling capacitance established by the capacitor 108 may set the filtering frequency utilized by the filter resonator 106. Additionally, the output of the filter resonator 106 may drive the RIP gate 102. In various embodiments, each filter resonator 106 may be tuned by a respective coupling capacitance to filter the multiplexed signals in respective frequency bands. Thereby, each RIP gate 102 may be driven by different RIP gate signals even though the various RIP gate signals are supplied from the same signal control line 104.

[0027] FIG. 2 shows an exemplary and non-limiting frequency multiplexing scheme 200 that may characterize a multiplexed control signal 202 carried on the signal control line 104, according to one or more embodiments described herein. Repeated descriptions of similar elements utilized in other embodiments described herein are omitted for brevity. In various embodiments, the frequency multiplexing scheme 200 may be utilized by the quantum controller 112 via a multiplexer. In one or more embodiments, the quantum controller 112 may utilize orthogonal frequency division multiplexing to multiplex a plurality of RIP signals onto the signal control line 104.

[0028] As shown in FIG. 2, the bandwidth of the multiplexed control signal can be divided into a series of non-overlapping frequency sub-bands that can each be used to carry a separate RIP gate signal. For example, the first RIP gate signal 204a can be carried on a frequency sub-band centered at 6.2 gigahertz (GHz). The second RIP gate signal 204b can be carried in a second frequency sub-band, such as a frequency sub-band centered at 6.3 GHz. Similarly, additional RIP gate signals can be carried in additional frequency bands, such as the “N” RIP gate signals 204n centered at 6.5 GHz. The multiplexed control signal 202 can be carried on the signal control line 104 to each of the filter resonators 106. The filter resonators 106 can then filter the RIP gate signal from the multiplexed control signal based on a frequency band division according to tuning established by the coupling capacitance of the resonator filters 106.

[0029] The frequency sub-bands centered at 6.2 GHz, 6.3 GHz, and 6.5 GHz are illustrated in FIG. 2, but the architecture of the frequency multiplexing is not so limited. Those skilled in the art will recognize that multiplexed control signals 202 with additional or alternative frequency-based divisions are also envisioned. For example, the RIP gate signal can be carried on a frequency sub-band centered at 6.1 or 6.4 GHz.

[0030] FIG. 3 shows a diagram of an exemplary and non-limiting quantum circuit 300 (e.g., circuit QED) that can include at least three qubits 302 coupled by at least two resonator buses 304 functioning as RIP gates 102 according to one or more embodiments described herein. Repeated descriptions of similar elements utilized in other embodiments described herein are omitted for brevity. As shown in FIG. 3, the exemplary quantum circuit 300 can utilize various features of the quantum circuit layout 100 described herein.

[0031] The exemplary quantum circuit 300 illustrated in FIG. 3 can include at least three qubits 302 (e.g., a first qubit 302a, a second qubit 302b, or a third qubit 302c, or a combination thereof). One of ordinary skill in the art will recognize that various qubit technologies can provide the basis for one or more qubits 302. For example, the qubit 302 can be a lithographically defined electronic circuit that can be cooled to millikelvin temperatures to exhibit quantized energy levels (e.g., due to quantized states of charge or magnetic flux), and can be a superconducting qubit (e.g., a superconducting quantum interference device “SQUID”, etc.). The superconducting qubit can be based on Josephson junctions, such as a transmon qubit or the like, or a combination thereof. Also, the superconducting qubit can be compatible with microwave control electronics and can be utilized with gate-based technology or integrated cryogenic control. In various embodiments, the qubit 302 can be a fixed-frequency superconducting qubit.

[0032] Furthermore, the coupling between qubits 302 can be controlled via at least two resonator buses 304 that can function as RIP gates 102. For example, a first resonator bus 304a can couple a first qubit 302a and a second qubit 302b. Also, a second resonator bus 304a can couple the second qubit 302b and a third qubit 302c. According to various embodiments described herein, the resonator bus 304 can be driven by the output of the filter resonator 106. For example, the first resonator bus 302a can be driven by the output of the first filter resonator 106a. Also, the second resonator bus 302b can be driven by the output of the second filter resonator 106b. Additionally, the coupling capacitance, and thereby the bandwidth of the filter resonator 106, can be defined by the capacitor 108. For example, a first capacitor 108a can set the coupling capacitance of the first filter resonator 106a. Also, a second capacitor 108b can set the coupling capacitance of the second filter resonator 106b. In one or more embodiments, the filter resonator 106 can be a band-pass filter such as a waveguide on the same plane. Further, in various embodiments, the signal control line 104 or the drive line 110 or a combination thereof can be a superconducting resonator line. Exemplary materials that can be included within one or more signal control lines 104 or drive lines 110 or a combination thereof include, but are not limited to, niobium, aluminum, lead, or indium, or a combination thereof, etc.

[0033] Figure 4 shows a diagram of an exemplary and non-limiting quantum circuit 300 in operation in which a frequency multiplexed control signal 202 can be carried by a signal control line 104 to control a resonator bus 304, according to one or more embodiments described herein. A repeated description of similar elements utilized in other embodiments described herein is omitted for brevity. Figure 4 illustrates how the quantum circuit 300 can route a RIP gate signal from a single signal control line 104 to multiple resonator buses 304.

[0034] As shown in FIG. 4, the frequency multiplexed control signal 202 can be represented by a thick black line and can be carried by the signal control line 104. For example, the frequency multiplexed control signal 202 can be multiplexed with the first RIP gate signal 204a or the second RIP gate signal 204b or both. In FIG. 4, the first RIP gate signal 204a can be represented by a thick dashed line and can be carried on the drive line 110 coupled to the first filter resonator 106a. Additionally, the second RIP gate signal 204b can be represented by a plurality of white circles and can be carried on the drive line 110 coupled to the second filter resonator 106b.

[0035] The signal control line 104 can carry the multiplexed control signal 202 (represented, for example, by a thick black line) to the first filter resonator 106a, which can thereby filter the multiplexed control signal 202 based on frequency and output the first RIP gate signal 204a (represented, for example, by a thick dashed line). The first filter resonator 106a can output the first RIP gate signal 204a as a control tone that can be carried to the first resonator bus 304a via the drive line 110. The first filter resonator 106a can also prevent other RIP gate signals, such as the second RIP gate signal 204b, from being carried to the first resonator bus 304a. Thus, the first resonator bus 304a can be driven only by the first RIP gate signal 204a output by the first filter resonator 106a, and crosstalk from other RIP gate signals can be reduced by the first filter resonator 106a. According to various embodiments described herein, the first filter resonator 106a can be tuned to the frequency band of the first RIP gate signal 204a by adjusting the coupling capacitance established by the first capacitor 108a.

[0036] In addition, the signal control line 104 may carry the multiplexed control signal 202 (represented, for example, by a thick black line) to the second filter resonator 106b, which may thereby filter the multiplexed control signal 202 based on frequency and output a second RIP gate signal 204b (represented, for example, by a white circle). The second filter resonator 106b may output the second RIP gate signal 204b as a control tone that may be carried to the second resonator bus 304b via another drive line 110. Also, the second filter resonator 106b may prevent other RIP gate signals, such as the first RIP gate signal 204a, from being carried to the second resonator bus 304b. Thus, the second resonator bus 304b may be driven only by the second RIP gate signal 204b output by the second filter resonator 106b, and crosstalk from other RIP gate signals may be reduced by the second filter resonator 106b. According to various embodiments described herein, the second filter resonator 106b may be tuned to the frequency band of the second RIP gate signal 204b by adjusting the coupling capacitance established by the second capacitor 108b.

[0037] By setting the first capacitor 108a to a capacitance different from that of the second capacitor 108b, the first filter resonator 106a may filter the multiplexed control signal 202 in a frequency band different from that of the second filter resonator 106b. Thereby, the first filter resonator 106a may output a target RIP gate signal (e.g., the first RIP gate signal 204a) while suppressing the propagation of other RIP gate signals (e.g., the second RIP gate signal 204b) to the first resonator bus 304a. Similarly, the second filter resonator 106b may output another target RIP gate signal (e.g., the second RIP gate signal 204b) while suppressing the propagation of other RIP gate signals (e.g., the first RIP gate signal 204a) to the second resonator bus 304b.

[0038] FIG. 5 shows another exemplary and non-limiting quantum circuit 500 (e.g., circuit QED) that may include at least four qubits 302 coupled by at least four resonator buses 304 functioning as RIP gates 102 according to one or more embodiments described herein. Repetitive descriptions of similar elements utilized in other embodiments described herein are omitted for brevity. As shown in FIG. 5, the exemplary quantum circuit 300 may utilize various features of the quantum circuit layout 100 described herein. Quantum circuit 500 illustrates that the architectures of the various embodiments described herein are not limited to two resonator buses 304 (e.g., the architecture is not limited to controlling two RIP gates 102). For example, quantum circuit 500 may utilize a single signal control line 104 to control more than two resonator buses 304, such as four resonator buses 304. Additionally, those skilled in the art will recognize that quantum circuits that control more than four resonator buses 304 using a single signal control line 104 are also envisioned.

[0039] Compared to quantum circuit 300, the exemplary quantum circuit 500 may include an additional fourth qubit 302d. Further, quantum circuit 500 may further include a third resonator bus 304c and a fourth resonator bus 304d to facilitate additional qubit couplings. Quantum circuit 500 illustrates that the features of the quantum circuit layout 100 may scale based on the number of qubit couplings controlled by the quantum circuit. For example, as the quantum circuit utilizes more qubits 302, the circuit may control more RIP gates 102, and more RIP gate signals may be multiplexed onto the signal control line 104.

[0040] For example, the third resonator bus 304c can couple the third qubit 302c and the fourth qubit 302d. Also, the fourth resonator bus 304d can couple the fourth qubit 302d and the first qubit 302a. According to various embodiments described herein, the resonator buses 304 can be driven by the output of the filter resonator 106. For example, the third resonator bus 304c can be driven by the output of the third filter resonator 106c. Also, the fourth resonator bus 304d can be driven by the output of the fourth filter resonator 106d. Additionally, the coupling capacitance, and thereby the bandwidth of the filter resonator 106, can be defined by the capacitor 108. For example, the third capacitor 108c can set the coupling capacitance of the third filter resonator 106c. Also, the fourth capacitor 108d can set the coupling capacitance of the fourth filter resonator 106d. In one or more embodiments, the filter resonator 106 can be a bandpass filter such as a waveguide on the same plane. Further, in various embodiments, the signal control line 104 or the drive line 110 or a combination thereof can be a superconducting resonator line.

[0041] FIG. 6 shows an exemplary and non-limiting quantum circuit 500 in operation in which a frequency multiplexed control signal 202 can be carried by a signal control line 104 to control a resonator bus 304, according to one or more embodiments described herein. A repeated description of similar elements utilized in other embodiments described herein is omitted for brevity. FIG. 6 illustrates how the quantum circuit 500 can route a RIP gate signal from a single signal control line 104 to multiple resonator buses 304.

[0042] As shown in FIG. 6, the frequency multiplexed control signal 202 can be represented by a thick black line and can be carried by the signal control line 104. For example, the frequency multiplexed control signal 202 can be multiplexed with the first RIP gate signal 204a, the second RIP gate signal 204b, the third RIP gate signal 204c, or the fourth RIP gate signal 204d or a combination thereof. In FIG. 6, the first RIP gate signal 204a is represented by a thick dashed line and can be carried on the drive line 110 coupled to the first filter resonator 106a. The second RIP gate signal 204b is represented by a plurality of white circles and can be carried on the drive line 110 coupled to the second filter resonator 106b. The third RIP gate signal 204c is represented by a plurality of white triangles and can be carried on the drive line 110 coupled to the third filter resonator 106c. The fourth RIP gate signal 204d is represented by a plurality of white diamonds and can be carried on the drive line 110 coupled to the fourth filter resonator 106d. According to various embodiments described herein, each of the RIP gate signals can be multiplexed into non-overlapping frequency bands. For example, the first RIP gate signal 204a (e.g., represented by a dashed line in FIG. 6) can be on a frequency sub-band concentrated at 6.2 GHz, the second RIP gate signal 204b (e.g., represented by white circles in FIG. 6) can be on a frequency sub-band concentrated at 6.3 GHz, the third RIP gate signal 204c (e.g., represented by white triangles in FIG. 6) can be on a frequency sub-band concentrated at 6.4 GHz, or the fourth RIP gate signal 204d (e.g., represented by white diamonds in FIG. 6) can be on a frequency sub-band concentrated at 6.5 GHz, or a combination thereof can exist.

[0043] The signal control line 104 may carry the multiplexed control signal 202 (represented, for example, by a thick black line) to the first filter resonator 106a, which may thereby filter the multiplexed control signal 202 based on frequency and output a first RIP gate signal 204a (represented, for example, by a thick dashed line). The first filter resonator 106a may output the first RIP gate signal 204a as a control tone that may be carried to the first resonator bus 304a via the drive line 110. The first filter resonator 106a may also prevent other RIP gate signals (such as a second RIP gate signal 204b, a third RIP gate signal 204c, and a fourth RIP gate signal 204d) from being carried to the first resonator bus 304a. Thus, the first resonator bus 304a may be driven only by the first RIP gate signal 204a output by the first filter resonator 106a, and crosstalk from other RIP gate signals may be reduced by the first filter resonator 106a. According to various embodiments described herein, the first filter resonator 106a may be tuned to the frequency band of the first RIP gate signal 204a by adjusting the coupling capacitance established by the first capacitor 108a.

[0044] In addition, the signal control line 104 can carry the multiplexed control signal 202 (represented, for example, by a thick black line) to the second filter resonator 106b, which can thereby filter the multiplexed control signal 202 based on frequency and output a second RIP gate signal 204b (represented, for example, by a white circle). The second filter resonator 106b can output the second RIP gate signal 204b as a control tone that can be carried to the second resonator bus 304b via another drive line 110. Also, the second filter resonator 106b can prevent other RIP gate signals (e.g., the first RIP gate signal 204a, the third RIP gate signal 204c, and the fourth RIP gate signal 204d) from being carried to the second resonator bus 304b. Thus, the second resonator bus 304b can be driven only by the second RIP gate signal 204b output by the second filter resonator 106b, and crosstalk from other RIP gate signals can be reduced by the second filter resonator 106b. According to various embodiments described herein, the second filter resonator 106b can be tuned to the frequency band of the second RIP gate signal 204b by adjusting the coupling capacitance established by the second capacitor 108b.

[0045] Furthermore, the signal control line 104 may carry the multiplexed control signal 202 (represented, for example, by a thick black line) to the third filter resonator 106c, which may thereby filter the multiplexed control signal 202 based on frequency and output a third RIP gate signal 204c (represented, for example, by a white triangle). The third filter resonator 106c may output the third RIP gate signal 204c as a control tone that may be carried to the third resonator bus 304c via another drive line 110. Also, the third filter resonator 106c may prevent other RIP gate signals from being carried to the third resonator bus 304c (for example, it may prevent the first RIP gate signal 204a, the second RIP gate signal 204b, and the fourth RIP gate signal 204d). Thus, the third resonator bus 304c may be driven only by the third RIP gate signal 204c output by the third filter resonator 106c, and crosstalk from other RIP gate signals may be reduced by the third filter resonator 106c. According to various embodiments described herein, the third filter resonator 106c may be tuned to the frequency band of the third RIP gate signal 204c by adjusting the coupling capacitance established by the third capacitor 108c.

[0046] Furthermore, the signal control line 104 may carry the multiplexed control signal 202 (represented, for example, by a thick black line) to the fourth filter resonator 106d, which may thereby filter the multiplexed control signal 202 based on frequency and output a fourth RIP gate signal 204d (represented, for example, by a white diamond). The fourth filter resonator 106d may output the fourth RIP gate signal 204d as a control tone that may be carried to the fourth resonator bus 304d via another drive line 110. Also, the fourth filter resonator 106d may prevent other RIP gate signals from being carried to the fourth resonator bus 304d (for example, it may prevent the first RIP gate signal 204a, the second RIP gate signal 204b, and the third RIP gate signal 204c). Thus, the fourth resonator bus 304d may be driven only by the fourth RIP gate signal 204d output by the fourth filter resonator 106d, and crosstalk from other RIP gate signals may be reduced by the fourth filter resonator 106d. According to various embodiments described herein, the fourth filter resonator 106d may be tuned to the frequency band of the fourth RIP gate signal 204d by adjusting the coupling capacitance established by the fourth capacitor 108d.

[0047] By setting each capacitor 108 to a different capacitance, each filter resonator 106 may filter the multiplexed control signal 202 in a different frequency band. Thereby, each filter resonator 106 may output different targeted RIP gate signals while suppressing the propagation of other RIP gate signals to the respective resonator buses 304 of the filter resonator 106.

[0048] FIG. 7 shows an exemplary and non - limiting graph 700 that can demonstrate the operation of the exemplary quantum circuit 500 illustrated in FIG. 6, according to one or more embodiments described herein. Repeated descriptions of similar elements utilized in other embodiments described herein are omitted for brevity. Graph 700 characterizes one embodiment of the frequency multiplexing scheme 200 implemented on the exemplary quantum circuit 500 according to various embodiments described herein.

[0049] As shown in FIG. 7, the first RIP gate signal 204a may be depicted by "m1", the second RIP gate signal 204b may be depicted by "m2", the third RIP gate signal 204c may be depicted by "m3", and the fourth RIP gate signal 204d may be depicted by "m4". The frequency multiplexing scheme 200 shown in graph 700 can achieve at least 20 dB resonator bus 304 selectivity at the target drive frequencies of the respective RIP gate signals (e.g., at target drive frequencies of 6.2 GHz, 6.3 GHz, 6.4 GHz, or 6.4 GHz or combinations thereof). For example, the reference signs "m5", "m6", "m7", or "m8", or combinations thereof, may depict crosstalk that may occur outside the 20 dB selectivity range.

[0050] FIG. 8 shows a flowchart of an exemplary and non - limiting method 800 that may be implemented by one or more quantum circuits (e.g., circuit QED) for controlling quantum gate coupling, according to one or more embodiments described herein. Repeated descriptions of similar elements utilized in other embodiments described herein are omitted for brevity.

[0051] At 802, method 800 may include setting the bandwidth of filter resonator 106 via a quantum circuit (such as illustrated by exemplary quantum circuit 300 or 500 or both) by adjusting the coupling capacitance between filter resonator 106 and signal control line 104 that can be multiplexed with a plurality of RIP gate signals. For example, signal control line 104 may be frequency division multiplexed such as multiplexing illustrated in frequency multiplexing scheme 200 or graph 700 or both. In various embodiments, filter resonator 106 may be from a plurality of filter resonators 106 included within the same quantum circuit. Additionally, filter resonator 106 may be a bandpass filter or a bandstop filter. In various embodiments, filter resonator 106 may be a waveguide filter on the same plane. In one or more embodiments, the step of setting the bandwidth at 802 may be performed by setting the capacitance of one or more capacitors 108 that couple filter resonator 106 to signal control line 104.

[0052] At 804, method 800 may include controlling quantum gate coupling via a quantum circuit (such as illustrated by exemplary quantum circuit 300 or 500 or both) by filtering the RIP gate signal from signal control line 104, where the RIP gate signal may be filtered from the signal control line by a filter resonator based on a frequency corresponding to the bandwidth. For example, filter resonator 106 may couple to one or more RIP gates 102 (such as one or more resonator buses 304 that couple a plurality of qubits 302). In various embodiments, signal control line 104 may drive a plurality of RIP gates 102, and crosstalk between RIP gates 102 may be reduced by filter resonator 106.

[0053] FIG. 9 shows a flow diagram of an exemplary and non-limiting method 900 that may be implemented by one or more quantum circuits (e.g., circuit QED) for controlling quantum gate couplings according to one or more embodiments described herein. Repeated descriptions of similar elements utilized in other embodiments described herein are omitted for brevity.

[0054] At 902, method 900 may comprise multiplexing a plurality of RIP gate signals onto signal control line 104 via quantum controller 112. For example, signal control line 104 may be frequency division multiplexed such as the multiplexing illustrated in frequency multiplexing scheme 200 or graph 700 or both. In one or more embodiments, the multiplexing step at 902 may be implemented by one or more quantum controllers 112 (e.g., via one or more multiplexers 114) that may stimulate a quantum circuit (e.g., exemplary quantum circuit 300 or 500 or both) including signal control line 104.

[0055] At 904, method 900 may comprise routing signal control line 104 through one or more filter resonators 106 via a quantum circuit (such as illustrated by, e.g., exemplary quantum circuit 300 or 500 or both). For example, signal control line 104 may carry multiplexed control signal 202 to one or more filter resonators 106. As illustrated at least in FIGS. 1 and 3 - 6, multiplexed control signal 204 may be carried by signal control line 104 to a plurality of filter resonators 106.

[0056] At 906, method 900 may include coupling the output of one or more filter resonators 106 to one or more RIP gates 102 via a quantum circuit (such as exemplified by exemplary quantum circuit 300 or 500 or both). For example, each filter resonator 106 may be coupled to a respective RIP gate 102 (coupled to a respective resonator bus 304 that couples, for example, two or more qubits 302). The output of one or more filter resonators 106 may drive the RIP gates 102.

[0057] At 908, method 900 may include setting the bandwidth of one or more filter resonators 106 via a quantum circuit (such as exemplified by exemplary quantum circuit 300 or 500 or both) by adjusting the coupling capacitance between the one or more filter resonators 106 and the signal control line 104. For example, the one or more filter resonators 106 may be coupled to the signal control line 104 via one or more capacitors 108. The bandwidth of the filter resonator 106 may be tuned by adjusting the capacitance of the capacitor 108 such that the filter resonator 106 outputs a RIP gate signal that is driven at a target frequency sub-band. In various embodiments, one or more of the filter resonators 106 may be set to different bandwidths, thereby filtering the multiplexed control signal 202 based on different target frequencies.

[0058] At 910, method 900 may include generating an output via a quantum circuit (such as, for example, illustrated by exemplary quantum circuit 300 or 500 or both) by filtering a RIP gate signal from a plurality of multiplexed RIP gate signals at 902 via one or more filter resonators 106. For example, filter resonator 106 may output an individual RIP gate signal from multiplexed control signal 202 based on a target frequency defined by a bandwidth set at 908. In various embodiments, each filter resonator 106 may output a respective RIP gate signal for driving a respective RIP gate 102 at a different frequency.

[0059] To provide additional context for various embodiments described herein, FIGS. 10 and the following description are intended to provide a general description of a suitable computing environment 1000 in which various embodiments described herein may be implemented. In various embodiments, computing environment 1000 may illustrate one or more computer devices utilized to communicate with or provide input to or both to quantum controller 112, or structural features of both. Although embodiments have been described above in the general context of computer-executable instructions that may be executed on one or more computers, those skilled in the art will recognize that embodiments may also be implemented in combination with other program modules, or as a combination of hardware and software, or both.

[0060] Generally, a program module includes routines, programs, components, data structures, etc. that perform a particular task or implement a particular abstract data type. Further, those skilled in the art will understand that the inventive method can be implemented using a single-processor or multi-processor computer system, a minicomputer, a mainframe computer, a mono Internet of Things (「IoT」) device, a distributed computing system, and other computer system configurations including a personal computer, a handheld computing device, or other electronic devices for consumers based on a microprocessor or programmable, in which each of these can be operably coupled to one or more associated devices.

[0061] The illustrated embodiments of the present specification can also be implemented in a distributed computing environment where a particular task is performed by a remote processing device linked through a communication network. In a distributed computing environment, program modules can be located in both local and remote memory storage devices. For example, in one or more embodiments, computer-executable components can be executed from a memory that can include or be constituted by one or more distributed memory units. As used herein, the terms 「memory」 and 「memory unit」 are interchangeable. Further, one or more embodiments described herein can execute the code of computer-executable components in a distributed manner, for example, multiple processors can operate in combination or jointly to execute code from one or more distributed memory units. As used herein, the term 「memory」 can include a single memory or memory unit at one location, or multiple memories, or a single memory or memory unit in a memory unit at one or more locations.

[0062] A computing device typically includes various media that may include a computer-readable storage medium, a machine-readable storage medium, or a communication medium, or a combination thereof, as the two terms are used herein to be distinct from each other as follows. A computer-readable storage medium or a machine-readable storage medium can be any available storage medium that can be accessed by a computer and includes both volatile and non-volatile media, and both removable and non-removable media. By way of example and not limitation, a computer-readable storage medium or a machine-readable storage medium can be implemented in connection with any method or technology for storing information such as computer-readable instructions or machine-readable instructions, program modules, structured data or unstructured data, etc.

[0063] A computer-readable storage medium can include, without limitation, random access memory (“RAM”), read only memory (“ROM”), electrically erasable programmable read only memory (“EEPROM”), flash memory or other memory technology, compact disc read only memory (“CD-ROM”), digital versatile disc (“DVD”), Blu-ray disc (“BD”) or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device, solid state drive or other solid state storage device, or other tangible or non-transitory media that can be used to store desired information, or a combination thereof. In this regard, the terms “tangible” or “non-transitory” as used herein with respect to storage, memory, or computer-readable media should be understood to exclude only transient signals that propagate by themselves as modifiers, and do not waive rights to all standard storage, memory, or computer-readable media that are not transient signals that propagate by themselves only.

[0064] A computer-readable storage medium can be accessed by one or more local or remote computing devices via, for example, access requests, queries, or other data acquisition protocols for various operations regarding the information stored by the medium.

[0065] A communication medium typically embodies computer-readable instructions, data structures, program modules, or other structured or unstructured data in a modulated data signal, such as a data signal on a carrier wave or other transport mechanism, and includes any information delivery or transport medium. The term "modulated data signal" or signal refers to a signal having one or more of its characteristic sets, or a signal that has been altered in such a manner as to encode information within one or more signals. By way of example, and not limitation, communication media includes wired media such as a wired network or direct wired connection, and wireless media such as acoustic waves, RF, infrared, and other wireless media.

[0066] Referring again to FIG. 10, an exemplary environment 1000 for implementing various embodiments of the aspects described herein includes a computer 1002, the computer 1002 including a processing unit 1004, a system memory 1006, and a system bus 1008. The system bus 1008 couples system components including, without limitation, the system memory 1006 to the processing unit 1004. The processing unit 1004 can be any of a variety of commercially available processors. Dual microprocessors and other multiprocessor architectures can also be utilized as the processing unit 1004.

[0067] The system bus 1008 can be any of several types of bus architectures including a memory bus, a peripheral bus, and a local bus using any of a variety of commercially available bus architectures (with or without a memory controller). The system memory 1006 includes ROM 1010 and RAM 1012. The basic input / output system ("BIOS") can be stored in non-volatile memory such as ROM, erasable programmable read-only memory ("EPROM"), EEPROM, etc., including basic routines that help transfer information between elements within the computer 1002 during startup and the like. The RAM 1012 can also include high-speed RAM such as static RAM for caching data.

[0068] The computer 1002 further includes an internal hard disk drive (HDD) 1014 (e.g., EIDE, SATA), one or more external storage devices 1016 (e.g., magnetic floppy disk drive (FDD) 1016, memory stick or flash drive reader, memory card reader, etc.), and an optical disk drive 1020 (e.g., capable of reading from or writing to CD-ROM disks, DVDs, BDs, etc.). While the internal HDD 1014 is shown as being located within the computer 1002, the internal HDD 1014 can also be configured for external use in a suitable chassis (not shown). Additionally, although not shown in the environment 1000, a solid state drive (SSD) can be used in addition to, or instead of, the HDD 1014. The HDD 1014, external storage device 1016, and optical disk drive 1020 can each be connected to the system bus 1008 by an HDD interface 1024, an external storage interface 1026, and an optical drive interface 1028, respectively. The interface 1024 for external drive implementations can include at least one or both of the Universal Serial Bus (USB) and Institute of Electrical and Electronics Engineers (IEEE) 1394 interface technologies. Other external drive connection technologies are included within the scope of the embodiments described herein.

[0069] The drive and its associated computer-readable storage medium provide non-volatile storage of data, data structures, computer-executable instructions, and the like. For computer 1002, the drive and storage medium accommodate storage of any data in a suitable digital format. The foregoing description of computer-readable storage media refers to each type of storage device, but other types of storage media that are computer-readable, whether presently existing or to be developed in the future, may be used in exemplary operating environments, and furthermore, it should be understood by those skilled in the art that any such storage media may contain computer-executable instructions for performing the methods described herein.

[0070] Some program modules, including operating systems 1030, one or more application programs 1032, other program modules 1034, and program data 1036, may be stored on the drive and in RAM 1012. All or part of an operating system, application, module, or data, or a combination thereof, may also be cached in RAM 1012. The systems and methods described herein may be implemented using a variety of commercially available operating systems or combinations of operating systems.

[0071] Computer 1002 may optionally include emulation technology. For example, a hypervisor (not shown) or other intermediary may emulate the hardware environment for operating system 1030, and the emulated hardware may optionally differ from the hardware shown in FIG. 10. In such an embodiment, operating system 1030 may include one virtual machine (VM) of a plurality of virtual machines (VMs) hosted on computer 1002. Further, operating system 1030 may provide a runtime environment such as a Java (registered trademark) runtime environment or a.NET framework for application 1032. The runtime environment is a consistent execution environment that enables application 1032 to be executed on any operating system that includes the runtime environment. Similarly, operating system 1030 may support containers, for example, lightweight, stand-alone, and executable packages of software that include code, runtime, system tools, system libraries, and settings for an application, and application 1032 may be in the form of a container.

[0072] Furthermore, computer 1002 may be enabled using a security module such as a trusted processing module (TPM). For example, using the TPM, a boot component hashes the next upcoming boot component in time and waits for the result to match a protected value before loading the next boot component. This process may occur at any layer in the code execution stack of computer 1002, for example, applied at the application execution level or the operating system (OS) kernel level, thereby enabling security at any level of code execution.

[0073] The user can input commands and information into the computer 1002 through one or more wired / wireless input devices, such as a keyboard 1038, a touch screen 1040, and a pointing device such as a mouse 1042. Other input devices (not shown) may include a microphone, an infrared (IR) remote control, a radio frequency (RF) remote control, or other remote controls, a joystick, a virtual reality controller or virtual reality headset or a combination thereof, a gamepad, a stylus pen, an image input device such as a camera, a gesture sensor input device, a vision movement sensor input device, an emotion or face detection device, or a biometric input device such as a fingerprint or iris scanner, etc. These and other input devices are often connected to the processing unit 1004 through an input device interface 1044 that can be coupled to the system bus 1008, but can also be connected by other interfaces such as a parallel port, an IEEE 1394 serial port, a game port, a USB port, an IR interface, a BLUETOOTH (registered trademark) interface, etc.

[0074] A monitor 1046 or other type of display device can also be connected to the system bus 1008 through an interface such as a video adapter 1048. In addition to the monitor 1046, the computer typically includes other peripheral output devices (not shown) such as speakers, printers, etc.

[0075] Computer 1002 may operate in a networked environment using logical connections through wired communication, wireless communication, or a combination thereof to one or more remote computers such as remote computer 1050. Remote computer 1050 can be a workstation, server computer, router, personal computer, portable computer, microprocessor-based entertainment device, peer device, or other common network node, and typically only memory / storage device 1052 is shown for simplicity, but includes many or all of the elements described with respect to computer 1002. The illustrated logical connections include a wired / wireless connection to a local area network ("LAN") 1054, or a larger network, such as a wide area network ("WAN") 1056, or a combination thereof. Such LAN and WAN networking environments are common in offices and enterprises, facilitating enterprise-scale computer networks such as intranets, all of which can be connected to a global communication network, such as the Internet.

[0076] When used in a LAN networking environment, computer 1002 can be connected to local network 1054 through a wired, wireless, or combination communication network interface or adapter 1058. Adapter 1058 can facilitate wired or wireless communication to LAN 1054, and can also include a wireless access point ("AP") disposed therein for communicating with adapter 1058 in wireless mode.

[0077] When used in a WAN networking environment, computer 1002 may include a modem 1060 or may be connected to a communication server on WAN 1056 via other means for establishing communication on WAN 1056 such as the Internet. Modem 1060, which can be internal or external and can be a wired or wireless device, can be connected to system bus 1008 via input device interface 1044. In a networked environment, program modules illustrated with respect to computer 1002 or portions thereof can be stored in remote memory / storage device 1052. The network connections shown are exemplary, and it will be understood that other means of establishing a communication link between computers can be used.

[0078] When used in either a LAN networking environment or a WAN networking environment, computer 1002 can access a cloud storage system or other network-based storage system in addition to, or instead of, external storage device 1016 as described above. Generally, the connection between computer 1002 and the cloud storage system can be established on LAN 1054 or WAN 1056, for example, by respective adapter 1058 or modem 1060. When connecting computer 1002 to an associated cloud storage system, external storage interface 1026 can manage the storage provided by the cloud storage system to manage other types of external storage using the assistance of adapter 1058 or modem 1060, or a combination thereof. For example, external storage interface 1026 can be configured to provide access to cloud storage sources as if those sources were physically connected to computer 1002.

[0079] Computer 1002 can be operable to communicate with, for example, a printer, a scanner, a desktop or portable computer or a combination thereof, a portable data assistant, a communication satellite, any device or location associated with a wirelessly detectable tag (e.g., a kiosk, a newsstand, a store shelf, etc.), and any wireless device or entity operably disposed in wireless communication, such as a telephone. This may include wireless fidelity (“Wi-Fi (registered trademark)”) and BLUETOOTH (registered trademark) wireless technologies. Thus, the communication can be of a pre-defined structure similar to a conventional network, or simply an ad-hoc communication between at least two devices.

[0080] What has been described above includes merely examples of a system, a computer program product, and a computer-implemented method. Of course, it is not possible to describe every conceivable combination of components, products, or computer-implemented methods, or combinations thereof, for the purpose of describing the present disclosure, but those skilled in the art may recognize that many more combinations and permutations of the present disclosure are possible. Further, as used in the detailed description, the claims, the accompanying documents, and the drawings, terms such as “including,” “having,” “comprising,” etc., are intended to be inclusive in a manner similar to the way the term “comprising” is interpreted when used as a transitional phrase in a claim. The descriptions of the various embodiments have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein has been selected to best explain the principles of the embodiments, the practical application of the technology found in the marketplace, or a technical improvement thereof, or to enable others skilled in the art to understand the embodiments disclosed herein. 。 [Item 1] Controlling quantum gate coupling via a quantum circuit by filtering resonator-induced phase gate signals from a plurality of resonator-induced phase gate signals and a multiplexed signal control line A method comprising the steps of: [Item 2] The method according to the preceding item, wherein the filtering is performed by a filter resonator coupled between the signal control line and the resonator bus. [Item 3] The method according to the preceding item, wherein the resonator bus is a resonator-induced phase gate between a plurality of superconducting qubits. [Item 4] Setting a bandwidth of the filter resonator via the quantum circuit by adjusting a coupling capacitance between the filter resonator and the signal control line, wherein the resonator-induced phase gate signal is filtered from the signal control line by the filter resonator based on a frequency corresponding to the bandwidth The method according to any one of the two preceding items, further comprising the steps of: [Item 5] The method according to any one of the preceding items, wherein the plurality of resonator-induced phase gate signals are multiplexed onto the signal control line via frequency division multiplexing via a quantum controller, and the filtering is based on the frequency of the resonator-induced phase gate signal. [Item 6] Routing a signal control line to a filter resonator via a quantum circuit, wherein a plurality of resonator-induced phase gate signals are multiplexed onto the signal control line; and Coupling an output of the filter resonator to a resonator-induced phase gate via the quantum circuit A method comprising the steps of: [Item 7] The method according to the preceding item, wherein the output of the filter resonator is a resonator-induced phase gate signal from the plurality of resonator-induced phase gate signals. [Item 8] The filter resonator is from a plurality of filter resonators, and the resonator-induced phase gate is from a plurality of resonator-induced phase gates. The method further comprises coupling, via the quantum circuit, a second output of a second filter resonator from the plurality of filter resonators to a second resonator-induced phase gate that couples another plurality of superconducting qubits, according to the method described in the preceding item. [Item 9] The second output of the second filter resonator is a second resonator-induced phase gate signal from the plurality of resonator-induced phase gate signals, and the resonator-induced phase gate signal is different from the second resonator-induced phase gate signal, the method according to the preceding item. [Item 10] Setting a coupling capacitance between the filter resonator and the signal control line via the quantum circuit, wherein the filter resonator selects the resonator-induced phase gate signal from the plurality of resonator-induced phase gate signals based on the coupling capacitance The method according to any one of the three preceding items, further comprising. [Item 11] The method according to any one of the five preceding items, wherein the filter resonator prevents a second resonator-induced phase gate signal from the plurality of resonator-induced phase gate signals from being transmitted to the resonator-induced phase gate. [Item 12] The multiplexing is frequency division multiplexing, and the filter resonator generates the output by filtering the signal control line based on the frequencies of the plurality of resonator-induced phase gate signals, the method according to any one of the six preceding items. [Item 13] Setting a bandwidth of the filter resonator via the quantum circuit by adjusting a coupling capacitance between the filter resonator and the signal control line; and Generating the output via the quantum circuit by filtering a resonator-induced phase gate signal from the plurality of resonator-induced phase gate signals through the filter resonator The method according to any one of the seven preceding items, further comprising. [Item 14] The method according to the preceding item, wherein the filter resonator filters the resonator-induced phase gate signal at a frequency based on the bandwidth. [Item 15] A resonator bus coupled to a filter resonator, wherein the filter resonator outputs a control tone for driving the resonator bus from a plurality of control tones multiplexed on a quantum gate control line A system comprising. [Item 16] A capacitor for coupling the filter resonator to the quantum gate control line, wherein the frequency of the control tone is based on the capacitance of the capacitor The system according to the preceding item, further comprising. [Item 17] The system according to any one of the two preceding items, wherein the system is a multi-qubit circuit quantum electrodynamics system. [Item 18] The filter resonator is selected from the group consisting of a band-pass filter and a band-stop filter, the system according to any one of the three foregoing items. [Item 19] The quantum gate control line is multiplexed with a plurality of control tones, the control tones being from the plurality of control tones, the system according to any one of the four foregoing items. [Item 20] The control tone is a resonator-induced phase gate signal, and the resonator bus is a resonator-induced phase gate, the system according to any one of the five foregoing items.

Claims

1. A step of controlling the quantum gate coupling through the quantum circuit by filtering the resonator-induced phase gate signal from the signal control line on which the plurality of resonator-induced phase gate signals are multiplexed. A method for providing the above.

2. The method of claim 1 , wherein the filtering is performed by a filter resonator coupled between the signal control line and a resonator bus.

3. 3. The method of claim 2 , wherein the resonator bus is a resonator-induced phase gate between a plurality of superconducting qubits.

4. setting a bandwidth of the filter resonator through the quantum circuit by adjusting a coupling capacitance between the filter resonator and the signal control line, where the resonator-induced phase gate signal is filtered from the signal control line by the filter resonator based on a frequency responsive to the bandwidth. The method of claim 2 or 3, further comprising:

5. 5. The method of claim 1, wherein the plurality of resonator-induced phase gate signals are multiplexed onto the signal control line via frequency division multiplexing via a quantum controller, and the filtering is based on the frequency of the resonator-induced phase gate signals.

6. routing signal control lines through a quantum circuit to a filter resonator, where a plurality of resonator-induced phase gate signals are multiplexed onto the signal control lines; and coupling the output of the filter resonator to a resonator-induced phase gate via the quantum circuit. A method for providing the above.

7. The method of claim 6 , wherein the output of the filter resonator is a resonator-induced phase gated signal from the plurality of resonator-induced phase gated signals.

8. 8. The method of claim 7, wherein the filter resonator is from a plurality of filter resonators, and the resonator-induced phase gate is from a plurality of resonator-induced phase gates, the method further comprising coupling, via the quantum circuit, a second output of a second filter resonator from the plurality of filter resonators to a second resonator-induced phase gate that couples another plurality of superconducting qubits.

9. 9. The method of claim 8, wherein the second output of the second filter resonator is a second resonator-induced phase gate signal from the plurality of resonator-induced phase gate signals, and the resonator-induced phase gate signal is different from the second resonator-induced phase gate signal.

10. setting a coupling capacitance between the filter resonator and the signal control line via the quantum circuit, where the filter resonator selects the resonator-induced phase gate signal from the plurality of resonator-induced phase gate signals based on the coupling capacitance.

10. The method of any one of claims 7 to 9, further comprising:

11. 11. The method of claim 6, wherein the filter resonator prevents a second resonator-induced phase gate signal from the plurality of resonator-induced phase gate signals from being transmitted to the resonator-induced phase gate.

12. 12. The method of claim 6, wherein the multiplexing is frequency division multiplexing, and the filter resonator generates the output by filtering the signal control line based on the frequencies of the multiple resonator-induced phase gate signals.

13. setting a bandwidth of the filter resonator through the quantum circuit by adjusting a coupling capacitance between the filter resonator and the signal control line; and generating said output through said quantum circuit by filtering a resonator-induced phase gated signal from said plurality of resonator-induced phase gated signals through said filter resonator; 13. The method of any one of claims 6 to 12, further comprising:

14. The method of claim 13 , wherein the filter resonator filters the resonator-induced phase-gated signal with a frequency based on the bandwidth.

15. a resonator bus coupled to a filter resonator, the filter resonator outputting a control tone from a plurality of control tones multiplexed onto a quantum gate control line that drives the resonator bus; A system comprising:

16. a capacitor coupling the filter resonator to the quantum gate control line, where the frequency of the control tone is based on the capacitance of the capacitor. The system of claim 15 further comprising:

17. 17. The system of claim 15 or 16, wherein the system is a multi-qubit circuit quantum electrodynamics system.

18. 18. The system of claim 15, wherein the filter resonator is selected from the group consisting of a bandpass filter and a bandstop filter.

19. 19. The system of claim 15, wherein the quantum gate control line is multiplexed with a plurality of control tones, the control tone being from the plurality of control tones.

20. 20. The system of claim 15, wherein the control tone is a resonator induced phase gated signal and the resonator bus is a resonator induced phase gate.

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