Single-flux-quantum(SFQ)circuits have great potential in building cryogenic quantum-classical interfaces for scaling up superconducting quantum processors.SFQ-based quantum gates have been designed and realized.Howeve...Single-flux-quantum(SFQ)circuits have great potential in building cryogenic quantum-classical interfaces for scaling up superconducting quantum processors.SFQ-based quantum gates have been designed and realized.However,current control schemes are difficult to tune the driving strength to qubits,which restricts the gate length and usually induces leakage to unwanted levels.In this study,we design the scheme and corresponding pulse generator circuit to continuously adjust the driving strength by coupling SFQ pulses with variable intervals.This scheme not only provides a way to adjust the SFQ-based gate length,but also proposes the possibility to tune the driving strength envelope.Simulations show that our scheme can suppress leakage to unwanted levels and reduce the error of SFQ-based Clifford gates by more than an order of magnitude.展开更多
基金Project supported in part by the National Natural Science Foundation of China (Grant No.92065116)the Key-Area Research and Development Program of Guangdong Province,China (Grant No.2020B0303030002)+1 种基金the Shanghai Technology Innovation Action Plan Integrated Circuit Technology Support Program (Grant No.22DZ1100200)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDA18000000)。
文摘Single-flux-quantum(SFQ)circuits have great potential in building cryogenic quantum-classical interfaces for scaling up superconducting quantum processors.SFQ-based quantum gates have been designed and realized.However,current control schemes are difficult to tune the driving strength to qubits,which restricts the gate length and usually induces leakage to unwanted levels.In this study,we design the scheme and corresponding pulse generator circuit to continuously adjust the driving strength by coupling SFQ pulses with variable intervals.This scheme not only provides a way to adjust the SFQ-based gate length,but also proposes the possibility to tune the driving strength envelope.Simulations show that our scheme can suppress leakage to unwanted levels and reduce the error of SFQ-based Clifford gates by more than an order of magnitude.
