1. Quasiparticle Dynamics in Superconducting Quantum-Classical Hybrid Circuits
- Author
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Liu, Kuang, He, Xiaoliang, Niu, Zhengqi, Xue, Hang, Jiang, Wenbing, Ying, Liliang, Peng, Wei, Maezawa, Masaaki, Lin, Zhirong, Xie, Xiaoming, and Wang, Zhen
- Subjects
Quantum Physics - Abstract
Single flux quantum (SFQ) circuitry is a promising candidate for a scalable and integratable cryogenic quantum control system. However, the operation of SFQ circuits introduces non-equilibrium quasiparticles (QPs), which are a significant source of qubit decoherence. In this study, we investigate QP behavior in a superconducting quantum-classical hybrid chip that comprises an SFQ circuit and a qubit circuit. By monitoring qubit relaxation time, we explore the dynamics of SFQ-circuit-induced QPs. Our findings reveal that the QP density near the qubit reaches its peak after several microseconds of SFQ circuit operation, which corresponds to the phonon-mediated propagation time of QPs in the hybrid circuits. This suggests that phonon-mediated propagation dominates the spreading of QPs in the hybrid circuits. Our results lay the foundation to suppress QP poisoning in quantum-classical hybrid systems., Comment: 11 pages,13 figures
- Published
- 2023
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