報告題目： Free Mode Removal and Mode Decoupling for Simulating General Superconducting Quantum Circuits
報告人：趙匯海 博士 阿里巴巴達摩院
報告摘要：Superconducting quantum circuits is one of the leading candidates for a universal quantum computer. Designing novel qubit and multi-qubit superconducting circuits requires the ability to simulate and analyze the properties of a general circuit. In particular, going outside the transmon approach, we cannot make assumptions on anharmonicity, thus precluding blackbox quantization approaches. We consider and solve two issues involved in simulating general superconducting circuits. One of the issues often faced is the handling of free modes in the circuit, that is, circuit modes with no potential term in the Hamiltonian. Another issue is circuit size, namely the challenge of simulating large circuits. The main mathematical tool we use to address these issues is the linear canonical transformation in the setting of quantum mechanics. We address the first issue by giving a provably correct algorithm for removing free modes by performing a linear canonical transformation to completely decouple the free modes from other circuit modes. We address the second by giving a series of different linear canonical transformations to reduce inter-mode couplings, thereby reducing the overhead for classical simulation. We benchmark our decoupling methods by applying them to the circuit of two inductively coupled fluxonium qubits, obtaining several orders of magnitude acceleration in the computation of eigenstates.
報告人簡介：Huihai Zhao is a Quantum Scientist at Alibaba Quantum Lab (AQL). He received his BSc in Physics from Yuanpei Program of Peking University in 2007, and his PhD in condensed matter physics from Institute of Physics, Chinese Academy of Sciences in 2013. After that, he joined the University of Tokyo as a postdoctor. In 2017, he joined the Institute of Physical and Chemical Research (Riken) in Japan as a research scientist. His main research field is the computational many-body physics. He is currently leading the superconducting quantum processor design automation project at AQL.