The utilization of qudits in quantum systems has led to significant advantages in quantum computation and information processing.Therefore,qudits have gained increased attention in recent research for their precise an...The utilization of qudits in quantum systems has led to significant advantages in quantum computation and information processing.Therefore,qudits have gained increased attention in recent research for their precise and efficient operations.In this work,we demonstrate the complete population transfer between the next-adjacent energy levels of a transmon qudit using the Pythagorean coupling method and energy level mapping.We achieve a|0>to|2>transfer with a process fidelity of 97.76%in the subspace spanned by|0>to|2>.Moreover,the transfer operation is achieved within a remarkably fast timescale,as short as 20 ns.This study may present a promising avenue for enhancing the operation flexibility and efficiency of qudits in future implementations.展开更多
High fidelity two-qubit gates are fundamental for scaling up the superconducting qubit number.We use two qubits coupled via a frequency-tunable coupler which can adjust the coupling strength,and demonstrate the CZ gat...High fidelity two-qubit gates are fundamental for scaling up the superconducting qubit number.We use two qubits coupled via a frequency-tunable coupler which can adjust the coupling strength,and demonstrate the CZ gate using two different schemes,adiabatic and diabatic methods.The Clifford based randomized benchmarking(RB) method is used to assess and optimize the CZ gate fidelity.The fidelities of adiabatic and diabatic CZ gates are 99.53(8)% and 98.72(2)%,respectively.We also analyze the errors induced by the decoherence.Comparing to 30 ns duration time of adiabatic CZ gate,the duration time of diabatic CZ gate is 19 ns,revealing lower incoherence error rate r’_(incoherent),int=0.0197(5) compared to r_(incoherent,int)=0.0223(3).展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11890704,12004042,12104055,and 12104056)Natural Science Foundation of Beijing (Grant No.Z190012)Key Area Research and Development Program of Guangdong Province (Grant No.2018B030326001)。
文摘The utilization of qudits in quantum systems has led to significant advantages in quantum computation and information processing.Therefore,qudits have gained increased attention in recent research for their precise and efficient operations.In this work,we demonstrate the complete population transfer between the next-adjacent energy levels of a transmon qudit using the Pythagorean coupling method and energy level mapping.We achieve a|0>to|2>transfer with a process fidelity of 97.76%in the subspace spanned by|0>to|2>.Moreover,the transfer operation is achieved within a remarkably fast timescale,as short as 20 ns.This study may present a promising avenue for enhancing the operation flexibility and efficiency of qudits in future implementations.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11890704,12004042,and 11674376)the Natural Science Foundation of Beijing,China(Grant No.Z190012)+1 种基金the National Key Research and Development Program of China(Grant No.2016YFA0301800)the Key-Area Research and Development Program of Guang-Dong Province,China(Grant No.2018B030326001)。
文摘High fidelity two-qubit gates are fundamental for scaling up the superconducting qubit number.We use two qubits coupled via a frequency-tunable coupler which can adjust the coupling strength,and demonstrate the CZ gate using two different schemes,adiabatic and diabatic methods.The Clifford based randomized benchmarking(RB) method is used to assess and optimize the CZ gate fidelity.The fidelities of adiabatic and diabatic CZ gates are 99.53(8)% and 98.72(2)%,respectively.We also analyze the errors induced by the decoherence.Comparing to 30 ns duration time of adiabatic CZ gate,the duration time of diabatic CZ gate is 19 ns,revealing lower incoherence error rate r’_(incoherent),int=0.0197(5) compared to r_(incoherent,int)=0.0223(3).
