Siyuan Han

Simultaneous quantum state exchange or transfer between two sets of cavities via a superconducting coupler qubit

  1. Chui-Ping Yang,
  2. Qi-Ping Su,
  3. Shi-Biao Zheng,
  4. and Siyuan Han
We propose an approach to simultaneously perform quantum state exchange or transfer between two sets of cavities, each containing $N$ cavities, by using only one superconducting coupler
qubit. The quantum states to be exchanged or transferred can be arbitrary pure or mixed states. The operation time does not increase with the number of cavities, and there is no need of applying classic pulses during the entire operation. Moreover, the approach can be also applied to realize quantum state exchange or transfer between two sets of qubits, such as that between two multi-qubit quantum registers. The method can be generalized to other systems by using different types of physical qubit as a coupler to accomplish the same task.
arxiv pdf

Entanglement dynamics of a superconducting phase qubit coupled to a two-level system

  1. Guozhu Sun,
  2. Zhongyuan Zhou,
  3. Bo Mao,
  4. Xueda Wen,
  5. Peiheng Wu,
  6. and Siyuan Han
We report the observation and quantitative characterization of driven and spontaneous oscillations of quantum entanglement, as measured by concurrence, in a bipartite system consisting
of a macroscopic Josephson phase qubit coupled to a microscopic two-level system. The data clearly show the behavior of entanglement dynamics such as sudden death and revival, and the effect of decoherence and ac driving on entanglement.
arxiv pdf