Shi-Liang Zhu

Demonstration of Geometric Landau-Zener Interferometry in a Superconducting Qubit

  1. Xinsheng Tan,
  2. Dan-Wei Zhang,
  3. Zhentao Zhang,
  4. Yang Yu,
  5. Siyuan Han,
  6. and Shi-Liang Zhu
Geometric quantum manipulation and Landau-Zener interferometry have been separately explored in many quantum systems. In this Letter, we combine these two approaches to study the dynamics
of a superconducting phase qubit. We experimentally demonstrate Landau-Zener interferometry based on the pure geometric phases in this solid-state qubit. We observe the interference caused by a pure geometric phase accumulated in the evolution between two consecutive Landau-Zener transitions, while the dynamical phase is canceled out by a spin-echo pulse. The full controllability of the qubit state as a function of the intrinsically robust geometric phase provides a promising approach for quantum state manipulation.
arxiv pdf

Tunable interfaces for realizing universal quantum computation with topological qubits

  1. Zheng-Yuan Xue,
  2. L. B. Shao,
  3. Yong Hu,
  4. Shi-Liang Zhu,
  5. and Z. D. Wang
We propose to implement tunable interfaces for realizing universal quantum computation with topological qubits. One interface is between the topological and superconducting qubits,
which can realize arbitrary single-qubit gate on the topological qubit. When two qubits are involved, the interface between the topological qubits and a microwave cavity can induce a nontrivial two-qubit gate, which can not be constructed based on braiding operations. The two interfaces, being tunable via an external magnetic flux, may serve as the building blocks towards universal quantum computation with topological qubits.
arxiv pdf