电荷比特的超强藕合实现及量子态转移

基于超导量子电路中光与物质相互作用强度的可调性, 研究了库珀对盒子(Cooper-pair box, CPB)与LC谐振电路耦合的电路模型, 证明了可以通过减小CPB的约瑟夫森能量和增加LC谐振子阻抗, 实现光与物质的超强耦合(ultra-strong coupling, USC)和深度强耦合(deep-strong coupling, DSC)相互作用. 在此基础上, 进一步提出了具有一定抗噪性的 USC 双比特超导电路模型, 并以该模型作为非相干中介实现了两个Transmon系统间的量子态转移(quantum-state transfer, QST). 研究结果为在超导量子系统中实现USC相互作用提供了新的方案, 并有望进一步应用于量子调控、量子模拟和量子信息处理等领域.

Implementation of charge qubits in ultra-strong coupling regime and quantum-state transfer

The Cooper-pair box (CPB) capacitively coupled to an LC resonatorwas considered in a superconducting quantum circuit that permittedthe high adjustability of light-matter interactions. The deep-strongcoupling (DSC) and ultra-strong coupling (USC) regimes could beobtained by increasing the impedance of the LC resonator anddecreasing the Josephson energy of the qubit. In this regard, atwo-qubit circuit, as a coherent mediator with a promising degree ofnoise immunity, was used to transfer quantum states between pairs ofTransmon qubits. This study provided new insights into USC regimesin light-matter interaction systems. Furthermore, it contributed tothe fields of quantum control, quantum simulation, and quantuminformation processing with superconducting quantum circuits.