A radio frequency signal phase stabilization method and related device

Abstract

The present application discloses a method and related device for stabilizing the phase of a radio frequency signal, which is applied to an ion trap radio frequency controller. The method comprises: dividing the radio frequency signal output by a radio frequency signal source into an input radio frequency signal and a reference radio frequency signal; coupling the input radio frequency signal to a coupling antenna coil of the ion trap radio frequency controller to obtain an output radio frequency signal generated on a main resonant coil in the ion trap radio frequency controller; determining an error phase signal based on the output radio frequency signal, the reference radio frequency signal, and a phase-locked amplifier; and adjusting the capacitance of a voltage-controlled tuning capacitor in the ion trap radio frequency controller to a target capacitance value based on the error phase signal, thereby compensating for variations in the phase of the output radio frequency signal caused by disturbances in the main resonant coil in the ion trap radio frequency controller, reducing the phase noise of the output radio frequency signal, ensuring the stability of the secular motion frequency, extending the coherence time of quantum bits, and improving the fidelity of quantum computing.

Description

Technical Field

[0001] The present application relates to the technical field of ion traps, and in particular to a method for stabilizing the phase of a radio frequency signal and a related device. Background Art

[0002] As a core technology platform for quantum computing, the coherence of ion traps' phonon states directly determines system performance and application limits. In quantum computing, phonon decoherence accelerates the collapse of qubit states, leading to a decrease in the fidelity of quantum gate operations, severely restricting the accuracy of large-scale quantum algorithms.

[0003] The coherence of the phonon state in the ion trap is extremely sensitive to the frequency of secular motion. Unstable secular motion can cause the phonon state to decoherence, thereby affecting the fidelity of quantum computing.

[0004] Therefore, how to effectively improve the frequency stability of secular motion has become one of the technical problems that need to be urgently solved in the field of ion trap technology. Summary of the Invention

[0005] Based on the above problems, the present application provides a method and related devices for stabilizing the phase of radio frequency signals to compensate for the phase fluctuations of the output radio frequency signal, so that the phase of the radio frequency signal acting in the ion trap is stable, the frequency of secular motion is stable, the coherence time of quantum bits is extended, and the fidelity of quantum computing is improved.

[0006] The embodiments of this application disclose the following technical solutions:

[0007] In a first aspect, the present application discloses a method for stabilizing the phase of a radio frequency signal, which is applied to an ion trap radio frequency controller; the ion trap radio frequency controller includes a radio frequency resonant cavity and an ion trap; the radio frequency resonant cavity includes a voltage-controlled tuning capacitor, a coupling antenna coil, and a main resonant coil; the voltage-controlled tuning capacitor is connected in parallel to the coupling antenna coil; the main resonant coil is connected in series to the ion trap; the method comprises:

[0008] The radio frequency signal output by the radio frequency signal source is divided into an input radio frequency signal and a reference radio frequency signal;

[0009] coupling the input radio frequency signal to the coupling antenna coil to generate an output radio frequency signal on the main resonant coil;

[0010] determining an error phase signal based on the output RF signal, the reference RF signal, and a lock-in amplifier;

[0011] Based on the error phase signal, the capacitance value of the voltage-controlled tuning capacitor is adjusted to a target capacitance value; the target capacitance value is used to compensate for phase fluctuations of the output radio frequency signal.

[0012] In an optional implementation, the lock-in amplifier includes a phase detector, a low-pass filter, and an instrumentation amplifier; and determining the error phase signal based on the output RF signal, the reference RF signal, and the lock-in amplifier includes:

[0013] Mixing the output radio frequency signal and the reference radio frequency signal by the phase detector to obtain an initial phase signal;

[0014] Filtering the initial phase signal through the low-pass filter to obtain a filtered phase signal;

[0015] The filtered phase signal is amplified by the instrument amplifier to obtain the error phase signal.

[0016] In an optional implementation, the radio frequency resonator further includes a sampler; and the method further includes:

[0017] Adjusting the phase of the reference radio frequency signal by a phase shifter to obtain a phase-shifted reference radio frequency signal;

[0018] Sampling the output radio frequency signal generated by the main resonant coil by the sampler to obtain a sampled output radio frequency signal;

[0019] The mixing of the output RF signal and the reference RF signal by the phase detector to obtain an initial phase signal includes:

[0020] The phase detector mixes the phase-shifted reference RF signal and the sampled output RF signal to obtain the initial phase signal.

[0021] In an optional implementation, adjusting the capacitance value of the voltage-controlled tuning capacitor to a target capacitance value based on the error phase signal includes:

[0022] Analyzing the error phase signal by a servo controller to determine a control signal;

[0023] Based on the control signal, the capacitance value of the voltage-controlled tuning capacitor is adjusted to the target capacitance value.

[0024] In an optional implementation, dividing the radio frequency signal output by the radio frequency signal source into an input radio frequency signal and a reference radio frequency signal includes:

[0025] The radio frequency signal output by the radio frequency signal source is divided into the input radio frequency signal and the reference radio frequency signal by a power divider.

[0026] In an optional implementation, after obtaining the input radio frequency signal, the method further includes:

[0027] amplifying the input radio frequency signal by a radio frequency amplifier to obtain an amplified input radio frequency signal;

[0028] The step of coupling the input RF signal to the coupling antenna coil to generate an output RF signal on the main resonant coil is specifically as follows:

[0029] The amplified input radio frequency signal is coupled to the coupling antenna coil to generate an output radio frequency signal on the main resonant coil.

[0030] In an optional implementation, the sampler is connected in parallel with the main resonant coil; the sampler is composed of a first capacitor and a second capacitor connected in series; one end of the second capacitor is connected in series with one end of the first capacitor, and the other end of the second capacitor is grounded; the capacitance value of the first capacitor is much smaller than the capacitance value of the second capacitor; the capacitance value of the first capacitor is much smaller than the capacitance value of the equivalent capacitance of the ion trap; the output point of the sampler is located on the series circuit of the first capacitor and the second capacitor.

[0031] In a second aspect, the present application discloses a radio frequency signal phase stabilization device, the device comprising: a radio frequency signal source, a power divider, a radio frequency amplifier, an ion trap radio frequency controller, a phase shifter, a phase-locked amplifier, and a servo controller; the ion trap radio frequency controller comprises a radio frequency resonant cavity and an ion trap; the radio frequency resonant cavity comprises a voltage-controlled tuning capacitor, a coupling antenna coil, a main resonant coil, and a sampler; the voltage-controlled tuning capacitor is connected in parallel with the coupling antenna coil; the sampler is connected in parallel with the main resonant coil; and the main resonant coil is connected in series with the ion trap;

[0032] The radio frequency signal source is used to output a radio frequency signal;

[0033] The power splitter is used to split the radio frequency signal into an input radio frequency signal and a reference radio frequency signal;

[0034] The radio frequency amplifier is used to amplify the input radio frequency signal to obtain an amplified input radio frequency signal;

[0035] The ion trap radio frequency controller is configured to obtain an output radio frequency signal generated by the main resonant coil based on the amplified input radio frequency signal, and to sample the output radio frequency signal to obtain a sampled output radio frequency signal;

[0036] The phase shifter is used to adjust the phase of the reference radio frequency signal to obtain a phase-shifted reference radio frequency signal;

[0037] The lock-in amplifier is configured to determine an error phase signal based on the phase-shifted reference RF signal and the sampled output RF signal;

[0038] The servo controller is used to adjust the capacitance value of the voltage-controlled tuning capacitor to a target capacitance value based on the error phase signal; the target capacitance value is used to compensate for phase fluctuations of the output radio frequency signal.

[0039] A third aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method steps introduced in any implementation manner of the first aspect.

[0040] A fourth aspect of the present application provides an electronic device, including:

[0041] a memory having a computer program stored thereon;

[0042] A processor is used to execute the computer program in the memory to implement the steps of the method introduced in any implementation manner of the first aspect.

[0043] Compared with the existing technology, this application has the following beneficial effects:

[0044] The present application divides the RF signal output by the RF signal source into an input RF signal and a reference RF signal, couples the input RF signal to the coupled antenna coil of the ion trap controller, and generates an output RF signal in the main resonant coil of the ion trap controller; uses a phase-locked amplifier to process the output RF signal and the reference RF signal to determine an error phase signal; based on the error phase signal, adjusts the capacitance value of the voltage-controlled tuning capacitor to a target capacitance value, thereby compensating for the phase change of the output RF signal caused by the disturbance of the main resonant coil in the ion trap controller, reducing the phase noise of the newly generated output RF signal, ensuring the stability of the secular motion frequency, extending the coherence time of the quantum bit, and improving the fidelity of quantum computing. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0046] Figure 1 A schematic diagram showing how the phase of an output radio frequency signal varies with frequency noise, provided in an embodiment of the present application;

[0047] Figure 2 A schematic structural diagram of an ion trap radio frequency controller provided in an embodiment of the present application;

[0048] Figure 3 A flow chart of a method for stabilizing the phase of a radio frequency signal provided in an embodiment of the present application;

[0049] Figure 4 A schematic diagram of the structure of a radio frequency signal phase stabilization device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to help those skilled in the art better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0051] When ions are trapped using radio frequency signals to form an ion trap, they undergo simple harmonic oscillations within the trap. The characteristic frequency of this simple harmonic oscillation is the frequency of secular motion. The coherence of the phonon state in the ion trap is extremely sensitive to the frequency of secular motion. Unstable secular motion can cause decoherence of the phonon state, which in turn affects the fidelity of quantum computing.

[0052] After in-depth research, the inventors of this application discovered that when a single-frequency RF signal output by an RF signal source acts on a resonant cavity containing an ion trap, even the slightest deformation of the cavity can cause the input single-frequency RF signal to carry phase noise. This phase noise causes the single-frequency RF signal to exhibit a certain degree of spatial frequency broadening, thereby altering the original single-frequency motion state of the ions in the ion trap and ultimately causing decoherence of the phonon state within the ion trap.

[0053] Figure 1 A schematic diagram showing how the phase of an output RF signal varies with frequency noise, provided in an embodiment of the present application. Figure 1 The horizontal axis is frequency and the vertical axis is phase. Figure 1 Chinese d is the frequency of the input radio frequency signal that drives the oscillation of the resonant cavity where the ion trap is located (i.e., the radio frequency resonant cavity in this application), ω d Constant. Mechanical vibration or changes in ambient temperature can cause deformation of the resonant cavity where the ion trap resides, causing the resonant frequency of the cavity to change over time. ω0(t) is a function of the time-varying resonant frequency of the ion trap cavity. φ(t) represents the time-varying phase of the output RF signal under the influence of ω0(t).

[0054] from Figure 1 It can be seen that when the resonant cavity where the ion trap is located is deformed, the resonant frequency ω0(t) of the resonant cavity changes; when the resonant frequency ω0(t) changes, even if the frequency ω of the input RF signal d If the value remains unchanged, the phase of the output RF signal will also change significantly.

[0055] It should be emphasized that due to the principle of energy conservation, if the frequency of the input radio frequency signal driving the oscillation of the resonant cavity where the ion trap is located is ω d , then the frequency of the output RF signal is also ω d ω0(t) is the resonant frequency of the resonant cavity itself, not the frequency of the output RF signal. Although ω0(t) changes, it will not affect the frequency of the output RF signal ω d However, it will affect the phase change of the output RF signal, causing the phase of the output RF signal to carry the noise of φ(t).

[0056] Mechanical vibration or temperature changes can significantly affect the shape of the main resonant coil or coupled antenna coil in the RF resonant cavity. Therefore, when the resonant cavity contains devices such as coils, the change in the resonant frequency of the resonant cavity caused by the change in the shape of the resonant cavity is more obvious, and the phase fluctuation of the output RF signal caused by the change in the resonant frequency of the resonant cavity is more obvious.

[0057] Based on this, the present application proposes a method for stabilizing the phase of RF signals to compensate for the phase fluctuations of the output RF signal caused by the deformation of the RF resonant cavity where the ion trap is located, so that the phase of the RF signal acting in the ion trap is stable, the stability of the secular motion frequency is ensured, the coherence time of the quantum bit is extended, and the fidelity of quantum computing is improved.

[0058] The radio frequency signal phase stabilization method disclosed in this application is applied to an ion trap radio frequency controller. To facilitate understanding of the radio frequency signal phase stabilization method disclosed in this application, the ion trap radio frequency controller is first described.

[0059] Figure 2 This is a schematic diagram of the structure of an ion trap radio frequency controller provided in an embodiment of the present application. Figure 2 As shown, the ion trap radio frequency controller 200 disclosed in the present application includes a radio frequency resonant cavity 201 and an equivalent capacitor Ct of the ion trap.

[0060] The RF resonant cavity 201 includes a voltage-controlled tuning capacitor Cm, a coupling antenna coil La, a main resonant coil Lc, and a sampler 2011; the voltage-controlled tuning capacitor Cm is connected in parallel with the coupling antenna coil La; the sampler 2011 is connected in parallel with the main resonant coil Lc; and the main resonant coil Lc is connected in series with the equivalent capacitor Ct of the ion trap.

[0061] Among them, the sampler 2011 is composed of a first capacitor C1 and a second capacitor C2 in series; one end of the second capacitor C2 is connected in series with one end of the first capacitor C1, and the other end of the second capacitor C2 is grounded; the capacitance value X1 of the first capacitor C1 is much smaller than the capacitance value X2 of the second capacitor C2; the capacitance value X1 of the first capacitor C1 is much smaller than the capacitance value Xt of the equivalent capacitor Ct of the ion trap; the output point of the sampler 2011 is located on the series circuit of the first capacitor C1 and the second capacitor C2.

[0062] Figure 2 S0 is the input RF signal, Z0 is the input impedance, V C is the control voltage signal of the voltage-controlled tuning capacitor Cm; GND is S0 and V C R0 is the non-negligible resistance at the connection between the main resonant coil Lc and the ion trap; P is the output point of the sampler 2011; Ct is the equivalent capacitance of the ion trap.

[0063] Figure 2 The voltage at the output of sampler 2011 is Vp. Vp is expressed as: Vp = Vt × X1 ÷ (X1 + X2). In ion trap applications, Vt is the voltage applied by the RF resonant cavity 201 to the equivalent capacitance Ct of the ion trap; X1 is the capacitance of the first capacitor C1; and X2 is the capacitance of the second capacitor C2. Vt is on the order of hundreds of volts; Vp is on the order of several volts.

[0064] Figure 2 The value of X1 is on the order of 1 pF, the value of Xt is on the order of 10 pF, X2 is much larger than X1, and Xt is much larger than X1. Therefore, X1 has little effect on the overall resonance effect of the RF resonant cavity 201. When X1 uses a capacitor voltage with a high quality factor, the sampler 2011 will not affect the quality factor of the RF resonant cavity 201.

[0065] As previously explained, when mechanical vibration or ambient temperature changes cause deformation of the main resonant coil Lc, the resonant frequency of the resonant cavity containing the ion trap's equivalent capacitance Ct changes. While this change in the resonant cavity's frequency doesn't affect the frequency of the output RF signal, it does affect its phase, causing it to carry phase noise. Phase noise can cause the RF signal to broaden in spatial frequency, altering the originally single-frequency motion of the ions in the ion trap and causing decoherence of the phonon state within the trap.

[0066] Combine Figure 2As shown, when the input RF signal S0 is coupled to the coupling antenna coil La, a changing magnetic field is generated around the coupling antenna coil La; this changing magnetic field acts on the main resonant coil Lc through electromagnetic induction, causing an induced current to appear on the main resonant coil induction Lc. When the frequency of the input RF signal S0 matches the resonant frequency of the RF resonant cavity 201, the resonant cavity 201 will resonate, and energy will be efficiently converted and stored between the electric field and the magnetic field. In the resonant state, energy will be converted back and forth between the main resonant coil Lc and the equivalent capacitance Ct of the ion trap, thereby achieving effective energy transfer and amplification in the RF resonant cavity 201. The energy processed by the resonant circuit is finally transferred to the equivalent capacitance Ct of the ion trap, realizing the capture, storage and manipulation of ions.

[0067] It is understood that the higher the quality factor of the RF resonator 201, the smaller the energy loss and the higher the energy transfer efficiency. To ensure high energy transfer efficiency, those skilled in the art should ensure that the RF resonator has a high quality factor when screening components in the RF resonator.

[0068] Figure 2 The change in the resonant frequency of the intermediate frequency resonant cavity 201 is closely related to the change in the capacitance of the voltage-controlled tuning capacitor Cm. The relationship between the two can be expressed by the following equations.

[0069] The specific expression of the equation group is:

[0070]

[0071] ω in the equations R is the resonant frequency of the radio frequency resonant cavity 201; X La is the reactance of the coupling antenna coil La; k is the coupling coefficient describing the degree of electromagnetic coupling between the coupling antenna coil La and the main resonant coil Lc; Xm is Figure 2 The imaginary part of the complex impedance formed by the combined action of the input impedance Z0 and the voltage-controlled tuning capacitor Cm; Z 00 is the resistance value of the input impedance Z0, C m0 is the capacitance value of the voltage-controlled tuning capacitor Cm.

[0072] It should be emphasized that the value range of k is between 0 and 1. When k is close to 1, it indicates that the coupling between the coupling antenna coil La and the main resonant coil Lc is very tight. When k is close to 0, it indicates that the coupling between the coupling antenna coil La and the main resonant coil Lc is very weak.

[0073] It should be noted that, in this application, the capacitance value of the voltage-controlled tuning capacitor Cm is adjusted to change the resonant frequency, and the resonant frequency is not changed. Figure 2The reason for adding elements to the RF resonant cavity 201 to change the resonant frequency of the RF resonant cavity is that the latter solution will reduce the quality factor of the RF resonator, increase energy loss, and affect the energy transmission efficiency; the former solution can efficiently and simply change the resonant frequency of the RF resonant cavity while ensuring that the RF resonant cavity has a high quality factor.

[0074] It should be noted that the form of the RF resonant cavity is not limited to Figure 2 The spiral resonator shown in can also be in the form of other resonant cavities with antenna coupling, such as a coaxial resonant cavity or a waveguide resonant cavity.

[0075] Figure 3 This is a flowchart of a method for stabilizing the phase of a radio frequency signal provided in an embodiment of the present application. Figure 3 The RF signal phase stabilization method in Figure 2 On the ion trap radio frequency controller 200, Figure 3 The ion trap RF control, ion trap, voltage-controlled tuning capacitor, coupled antenna coil and main resonant coil involved are Figure 2 The ion trap radio frequency controller 200, the equivalent capacitance Ct of the ion trap, the voltage-controlled tuning capacitance Cm, the coupling antenna coil La and the main resonant coil Lc are combined. Figure 3 As shown, the radio frequency signal phase stabilization method disclosed in this application includes:

[0076] S301 , dividing a radio frequency signal output by a radio frequency signal source into an input radio frequency signal and a reference radio frequency signal.

[0077] Exemplarily, the radio frequency signal output by the radio frequency signal source may be divided into two signals through a power splitter, one signal being used as the input radio frequency signal and the other signal being used as the reference radio frequency signal.

[0078] S302: Couple the input radio frequency signal to the coupling antenna coil to generate an output radio frequency signal on the main resonant coil.

[0079] Specifically, an input RF signal can be input into an RF amplifier, which amplifies the input RF signal to produce an amplified input RF signal. This amplified input RF signal is then coupled to the coupling antenna coil of the ion trap RF controller. The interaction between the coupling antenna coil and the main resonant coil generates an induced current in the main resonant coil. In this application, the induced current generated in the main resonant coil is referred to as the output RF signal generated by the main resonant coil.

[0080] Since the power of the input RF signal output by the RF signal source is usually small, sometimes it cannot directly drive subsequent loads, such as ion traps; therefore, the present application amplifies the input RF signal through an RF amplifier to increase the power of the input RF signal so that it can effectively drive the ion trap and realize the capture, storage and manipulation of ions.

[0081] S303: Determine an error phase signal based on the output RF signal, the reference RF signal, and a lock-in amplifier.

[0082] As can be seen from the introduction of the aforementioned embodiments, in this application, part of the RF signal output by the RF signal source is used as a reference RF signal; and the induced current generated on the main resonant coil is used as the output RF signal.

[0083] After obtaining the reference RF signal, the reference RF signal is input into a phase shifter, and the phase of the reference RF signal is adjusted by the phase shifter to obtain a phase-shifted reference RF signal. The purpose of using a phase shifter to process the reference RF signal in this application is to make the error phase signal subsequently generated based on the reference RF signal and the output RF signal more significant, thereby facilitating observation and analysis.

[0084] After the output radio frequency signal is generated on the main resonant coil, the output radio frequency signal is sampled by a sampler to obtain a sampled output radio frequency signal.

[0085] After obtaining the phase-shifted reference RF signal and the sampled output RF signal, the phase-shifted reference RF signal and the sampled output RF signal can be input into a lock-in amplifier, which processes the two signals to determine the error phase signal.

[0086] The lock-in amplifier in this application includes a phase detector, a low-pass filter, and an instrumentation amplifier. The lock-in amplifier processes the phase-shifted reference RF signal and the sampled output RF signal to obtain the error signal, specifically:

[0087] After mixing the phase-shifted reference RF signal and the sampled output RF signal through a phase detector, the resulting demodulated signal is used as the initial phase signal; the initial phase signal is filtered through a low-pass filter to obtain a filtered phase signal; the filtered phase signal is amplified through an instrument amplifier to obtain an error phase signal.

[0088] S304: Adjust the capacitance value of the voltage-controlled tuning capacitor to a target capacitance value based on the error phase signal.

[0089] The target capacitance value in this application is used to compensate for the phase fluctuation of the output RF signal caused by the morphological change of the main resonant coil in the ion trap RF controller (mechanical vibration or ambient temperature may cause the morphology of the main resonant coil to change).

[0090] Specifically, after determining the error phase signal, the error phase signal is input into the servo controller, and the servo controller analyzes the error phase signal to determine the control signal; then, based on the control signal, the capacitance value of the voltage-controlled tuning capacitor is adjusted to the target capacitance value.

[0091] Thus, through this application Figure 3 According to the method, after obtaining the error phase, a matching voltage can be applied to the voltage-controlled tuning capacitor based on the error phase signal to adjust the capacitance value of the voltage-controlled tuning capacitor to a target capacitance; so that the target capacitance can compensate for the change in the resonant frequency of the RF resonant cavity caused by the deformation of the RF resonant cavity, so that the resonant frequency remains stable and the phase of the output RF signal remains stable.

[0092] Based on the radio frequency signal phase stabilization method provided in the aforementioned embodiment, the present application also provides a radio frequency signal phase stabilization device. Figure 4 A schematic diagram of the structure of a radio frequency signal phase stabilization device provided in an embodiment of the present application.

[0093] Combine Figure 4 As shown, the RF phase stabilization device 400 disclosed in the present application includes: a RF signal source 401, a power divider 402, a RF amplifier 403, an ion trap RF controller 404, a phase shifter 405, a lock-in amplifier 406 and a servo controller 407.

[0094] It should be noted that the ion trap radio frequency controller 404 is Figure 2 For the relevant contents of the ion trap radio frequency controller 200 and the ion trap radio frequency controller 404 disclosed in the specification, please refer to the introduction of the ion trap radio frequency controller 200 in the above embodiment, which will not be repeated here.

[0095] A radio frequency signal source 401 is used to transmit radio frequency signals externally;

[0096] The power divider 402 is used to divide the RF signal transmitted by the RF signal source 401 into an input RF signal and a reference RF signal; wherein the input RF signal is input to the RF amplifier 403; and the reference RF signal is input to the phase shifter 405.

[0097] The radio frequency amplifier 403 is used to amplify the input radio frequency signal to obtain an amplified input radio frequency signal; the amplified input radio frequency signal is the input radio frequency signal S0 of the ion trap radio frequency controller 404 .

[0098] The ion trap RF controller 404 is used to obtain the output RF signal generated by the main resonant coil Lc based on the amplified RF input signal; the output RF signal generated by the main resonant coil Lc is sampled by the sampler in the ion trap RF controller 404 to obtain the sampled output RF signal.

[0099] The phase shifter 405 is used to adjust the phase of the reference RF signal to obtain a phase-shifted reference RF signal; the phase-shifted reference RF signal is input into the phase detector 4061 of the lock-in amplifier 406.

[0100] a lock-in amplifier 406 for determining an error phase signal based on the phase-shifted reference RF signal and the sampled output RF signal;

[0101] The lock-in amplifier 406 includes a phase detector 4061, a low-pass filter 4062, and an instrumentation amplifier 4063. The sampled output RF signal from the sampler in the ion trap RF controller 404 and the phase-shifted reference RF signal from the phase shifter 405 are both input to the lock-in amplifier 406. The phase detector 4061 in the lock-in amplifier 406 mixes the two RF signals to obtain an initial phase signal. The initial phase signal is then input to the low-pass filter 4062, where it is processed to obtain a filtered phase signal. The filtered phase signal is then input to the instrumentation amplifier 4063, where it is processed to obtain an error phase signal.

[0102] The servo controller 407 is configured to: Figure 4 The control voltage signal Vc of the voltage-controlled tuning capacitor Cm is regulated to adjust the capacitance value of the voltage-controlled tuning capacitor Cm to a target capacitance value; the target capacitance value is used to compensate for the phase fluctuation of the output RF signal.

[0103] For example, the frequency of the radial secular motion of ytterbium ions in the ion trap is about 1-3 MHz. To ensure stable motion of the ytterbium ions in the ion trap, the 25 MHz RF signal generated by the RF signal source 401 can be split into an input RF signal and a reference RF signal by a power splitter 402.

[0104] On the one hand, after the input RF signal passes through the RF amplifier 403, it serves as the input RF signal S0 of the ion trap RF controller 404. Through the interaction between the coupling antenna coil La and the main resonant coil Lc, the induced signal generated on the main resonant coil Lc, that is, the output RF signal, is generated; then, the output RF signal is sampled using the sampler composed of capacitors C1 and C2 in the ion trap controller 404 to obtain the sampled output RF signal; on the other hand, the reference RF signal is processed by the phase shifter 406 to obtain a phase-shifted reference RF signal.

[0105] Then, the sampled output RF signal and the phase-shifted reference RF signal are input together into the phase-locked amplifier 406 to obtain an error phase signal; the error phase signal is then processed by the servo controller 407 to obtain a control signal; the control signal is connected to the control voltage signal Vc end of the voltage-controlled tuning capacitor Cm of the ion trap RF controller 404 to adjust the capacitance value of the voltage-controlled tuning capacitor Cm to the target capacitance value.

[0106] Because the capacitance of the voltage-controlled tuning capacitor Cm can affect Xm in the equation set in the aforementioned embodiment, thereby affecting the resonant frequency of the RF resonant cavity, and the error phase signal can also reflect the phase difference between the reference RF signal and the output RF signal, thereby reflecting the impact of RF resonant cavity deformation on the resonant frequency of the RF resonant cavity. Therefore, by analyzing the error signal, it is possible to clearly determine how to adjust the capacitance of the voltage-controlled tuning capacitor to compensate for the change in the resonant frequency of the RF resonant cavity caused by RF resonant cavity deformation, thereby ensuring that the phase of the output RF signal remains stable.

[0107] In summary, the present application discloses a method and device for stabilizing the phase of an RF signal, which determines an error phase signal representing the phase difference between the output RF signal and a reference RF signal by comparing the output RF signal and the reference RF signal; the RF resonant cavity of the ion trap RF controller includes a voltage-controlled tuning capacitor connected in parallel with the coupled antenna coil. After obtaining the error phase signal, the capacitance value of the voltage-controlled tuning capacitor is adjusted to compensate for the change in the resonant frequency of the RF resonator caused by the deformation of the RF resonant cavity, thereby ensuring that the phase of the output RF signal remains stable.

[0108] The present application discloses a method and device for stabilizing the phase of a radio frequency signal, which can generate a low-frequency, high-power and phase-stable radio frequency signal; in addition to being used in the field of ion traps, it can also be used in the fields of low-noise, high-power radio frequency generators and radio frequency amplifiers.

[0109] Based on the RF signal phase stabilization method and device provided in the aforementioned embodiments, the present application also provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, some or all of the steps in the RF signal phase stabilization method mentioned above are implemented.

[0110] Based on the radio frequency signal phase stabilization method and apparatus provided in the aforementioned embodiments, the present application further provides an electronic device, including:

[0111] a memory having a computer program stored thereon;

[0112] The processor is configured to execute the computer program in the memory to implement some or all of the steps in the radio frequency signal phase stabilization method provided in the aforementioned embodiment.

[0113] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The device embodiment described above is merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components indicated as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without expending creative work.

[0114] The above is merely one specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for stabilizing the phase of a radio frequency signal, characterized in that: The method is applied to an ion trap radio frequency controller; the ion trap radio frequency controller comprises a radio frequency resonant cavity and an ion trap; the radio frequency resonant cavity comprises a voltage-controlled tuning capacitor, a coupling antenna coil and a main resonant coil; The voltage-controlled tuning capacitor is connected in parallel with the coupling antenna coil; The main resonant coil is connected in series with the ion trap; the method comprises: The radio frequency signal output by the radio frequency signal source is divided into an input radio frequency signal and a reference radio frequency signal; Inputting the input RF signal into a RF amplifier, amplifying the input RF signal through the RF amplifier to obtain an amplified input RF signal; then coupling the amplified input RF signal to a coupling antenna coil of the ion trap RF controller, and generating an output RF signal on the main resonant coil through interaction between the coupling antenna coil and the main resonant coil; determining an error phase signal based on the output RF signal, the reference RF signal, and a lock-in amplifier; Based on the error phase signal, the capacitance value of the voltage-controlled tuning capacitor is adjusted to a target capacitance value; the target capacitance value is used to compensate for phase fluctuations of the output radio frequency signal.

2. The method according to claim 1, characterized in that The lock-in amplifier includes a phase detector, a low-pass filter, and an instrumentation amplifier; and determining an error phase signal based on the output RF signal, the reference RF signal, and the lock-in amplifier includes: Mixing the output RF signal and the reference RF signal by the phase detector to obtain an initial phase signal; Filtering the initial phase signal through the low-pass filter to obtain a filtered phase signal; The filtered phase signal is amplified by the instrument amplifier to obtain the error phase signal.

3. The method according to claim 2, characterized in that The radio frequency resonant cavity further includes a sampler; and the method further includes: Adjusting the phase of the reference radio frequency signal by a phase shifter to obtain a phase-shifted reference radio frequency signal; Sampling the output radio frequency signal generated by the main resonant coil by the sampler to obtain a sampled output radio frequency signal; The mixing of the output RF signal and the reference RF signal by the phase detector to obtain an initial phase signal includes: The phase detector mixes the phase-shifted reference RF signal and the sampled output RF signal to obtain the initial phase signal.

4. The method according to claim 1, wherein The adjusting the capacitance value of the voltage-controlled tuning capacitor to a target capacitance value based on the error phase signal includes: Analyzing the error phase signal by a servo controller to determine a control signal; Based on the control signal, the capacitance value of the voltage-controlled tuning capacitor is adjusted to the target capacitance value.

5. The method according to claim 1, characterized in that The step of dividing the radio frequency signal output by the radio frequency signal source into an input radio frequency signal and a reference radio frequency signal comprises: The radio frequency signal output by the radio frequency signal source is divided into the input radio frequency signal and the reference radio frequency signal by a power divider.

6. The method according to claim 3, characterized in that The sampler is connected in parallel with the main resonant coil; the sampler is composed of a first capacitor and a second capacitor connected in series; one end of the second capacitor is connected in series with one end of the first capacitor, and the other end of the second capacitor is grounded; the capacitance value of the first capacitor is much smaller than the capacitance value of the second capacitor; The capacitance value of the first capacitor is much smaller than the capacitance value of the equivalent capacitor of the ion trap; An output point of the sampler is located on a series connection between the first capacitor and the second capacitor.

7. A radio frequency signal phase stabilization device, characterized in that: The device comprises: a radio frequency signal source, a power divider, a radio frequency amplifier, an ion trap radio frequency controller, a phase shifter, a lock-in amplifier and a servo controller; the ion trap radio frequency controller comprises a radio frequency resonant cavity and an ion trap; the radio frequency resonant cavity comprises a voltage-controlled tuning capacitor, a coupling antenna coil, a main resonant coil and a sampler; the voltage-controlled tuning capacitor is connected in parallel with the coupling antenna coil; the sampler is connected in parallel with the main resonant coil; and the main resonant coil is connected in series with the ion trap; The radio frequency signal source is used to output a radio frequency signal; The power splitter is used to split the radio frequency signal into an input radio frequency signal and a reference radio frequency signal; The radio frequency amplifier is used to amplify the input radio frequency signal to obtain an amplified input radio frequency signal; The ion trap radio frequency controller is configured to obtain an output radio frequency signal generated by the main resonant coil based on the amplified input radio frequency signal, and to sample the output radio frequency signal to obtain a sampled output radio frequency signal; The phase shifter is used to adjust the phase of the reference radio frequency signal to obtain a phase-shifted reference radio frequency signal; The lock-in amplifier is configured to determine an error phase signal based on the phase-shifted reference RF signal and the sampled output RF signal; The servo controller is used to adjust the capacitance value of the voltage-controlled tuning capacitor to a target capacitance value based on the error phase signal; the target capacitance value is used to compensate for phase fluctuations of the output radio frequency signal.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

9. An electronic device, characterized in that: include: a memory having a computer program stored thereon; A processor, configured to execute the computer program in the memory to implement the steps of the method according to any one of claims 1 to 6.

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