As superconducting quantum circuits are scaling up rapidly towards the noisy intermediate-scale quantum(NISQ)era,the demand for electronic control equipment has increased significantly.To fully control a quantum chip ...As superconducting quantum circuits are scaling up rapidly towards the noisy intermediate-scale quantum(NISQ)era,the demand for electronic control equipment has increased significantly.To fully control a quantum chip of N qubits,the common method based on up-conversion technology costs at least 2×N digital-to-analog converters(DACs)and N IQ mixers.The expenses and complicate mixer calibration have become a hinderance for intermediate-scale quantum control.Here we propose a universal control scheme for superconducting circuits,fully based on parametric modulation.To control N qubits on a chip,our scheme only requires N DACs and no IQ mixer,which significantly reduces the expenses.One key idea in the control scheme is to introduce a global pump signal for single-qubit gates.We theoretically explain how the universal gates are constructed using parametric modulation.The fidelity analysis shows that parametric single-qubit(two-qubit)gates in the proposed scheme can achieve low error rates of 10^(4),with a gate time of about 60 ns(100 ns).展开更多
基金the National Key Research and Development Program of China(Grant No.2016YFA0301802)the National Natural Science Foundation of China(Grant Nos.11474152,12074179,and 61521001)the Young Fund of Jiangsu Natural Science Foundation of China(Grant No.BK20180750)。
文摘As superconducting quantum circuits are scaling up rapidly towards the noisy intermediate-scale quantum(NISQ)era,the demand for electronic control equipment has increased significantly.To fully control a quantum chip of N qubits,the common method based on up-conversion technology costs at least 2×N digital-to-analog converters(DACs)and N IQ mixers.The expenses and complicate mixer calibration have become a hinderance for intermediate-scale quantum control.Here we propose a universal control scheme for superconducting circuits,fully based on parametric modulation.To control N qubits on a chip,our scheme only requires N DACs and no IQ mixer,which significantly reduces the expenses.One key idea in the control scheme is to introduce a global pump signal for single-qubit gates.We theoretically explain how the universal gates are constructed using parametric modulation.The fidelity analysis shows that parametric single-qubit(two-qubit)gates in the proposed scheme can achieve low error rates of 10^(4),with a gate time of about 60 ns(100 ns).
