Zelong Yin

Shortcuts to Adiabaticity for Open Systems in Circuit Quantum Electrodynamics

  1. Zelong Yin,
  2. Chunzhen Li,
  3. Zhenxing Zhang,
  4. Yicong Zheng,
  5. Xiu Gu,
  6. Maochun Dai,
  7. Jonathan Allcock,
  8. Shengyu Zhang,
  9. and Shuoming An
Shortcuts to adiabaticity (STA) are powerful quantum control methods, allowing quick evolution into target states of otherwise slow adiabatic dynamics. Such methods have widespread
applications in quantum technologies, and various STA protocols have been demonstrated in closed systems. However, realizing STA for open quantum systems has presented a greater challenge, due to complex controls required in existing proposals. Here we present the first experimental demonstration of STA for open quantum systems, using a superconducting circuit QED system consisting of two coupled bosonic oscillators and a transmon qubit. By applying a counterdiabatic driving pulse, we reduce the adiabatic evolution time of a single lossy mode from 800 ns to 100 ns. In addition, we propose and implement an optimal control protocol to achieve fast and qubit-unconditional equilibrium of multiple lossy modes. Our results pave the way for accelerating dynamics of open quantum systems and have potential applications in designing fast open-system protocols of physical and interdisciplinary interest, such as accelerating bioengineering and chemical reaction dynamics.
arxiv pdf

Rapid and Unconditional Parametric Reset Protocol for Tunable Superconducting Qubits

  1. Yu Zhou,
  2. Zhenxing Zhang,
  3. Zelong Yin,
  4. Sainan Huai,
  5. Xiu Gu,
  6. Xiong Xu,
  7. Jonathan Allcock,
  8. Fuming Liu,
  9. Guanglei Xi,
  10. Qiaonian Yu,
  11. Hualiang Zhang,
  12. Mengyu Zhang,
  13. Hekang Li,
  14. Xiaohui Song,
  15. Zhan Wang,
  16. Dongning Zheng,
  17. Shuoming An,
  18. Yarui Zheng,
  19. and Shengyu Zhang
Qubit initialization is critical for many quantum algorithms and error correction schemes, and extensive efforts have been made to achieve this with high speed and efficiency. Here
we experimentally demonstrate a fast and high fidelity reset scheme for tunable superconducting qubits. A rapid decay channel is constructed by modulating the flux through a transmon qubit and realizing a swap between the qubit and its readout resonator. The residual excited population can be suppressed to 0.08% ± 0.08% within 34 ns, and the scheme requires no additional chip architecture, projective measurements, or feedback loops. In addition, the scheme has negligible effects on neighboring qubits, and is therefore suitable for large-scale multi-qubit systems. Our method also offers a way of entangling the qubit state with an itinerant single photon, particularly useful in quantum communication and quantum network applications.
arxiv pdf