Accelerating population transfer in a transmon qutrit via Shortcuts to adiabaticity

  1. Ye-Hong Chen,
  2. Zhi-Cheng Shi,
  3. Jie Song,
  4. Yan Xia,
  5. and Shi-Biao Zheng
In this paper, a method to accelerate population transfer by designing nonadiabatic evolution paths is proposed. We apply the method to realize robust and accelerated population transfer
with a transmon qutrit. By numerical simulation, we show that this method allows a robust population transfer between the ground states in a Λ system. Moreover, the total pulse area for the population transfer is low as 1.9π that verifies the evolution is accelerated without increasing the pulse intensity. Therefore, the method is easily implementable based on the modern pulse shaper technology and it provides selectable schemes with interesting applications in quantum information processing.

Complete Bell-state analysis for superconducting-quantum-interference-device qubits with transitionless tracking algorithm

  1. Yi-Hao Kang,
  2. Ye-Hong Chen,
  3. Zhi-Cheng Shi,
  4. Bi-Hua Huang,
  5. Jie Song,
  6. and Yan Xia
In this paper, we propose a protocol for complete Bell-state analysis for two superconducting-quantum-interference-device qubits. The Bell-state analysis could be completed by using
a sequence of microwave pulses designed by the transition- less tracking algorithm, which is an useful method in the technique of shortcut to adiabaticity. After the whole process, the information for distinguishing four Bell states will be encoded on two auxiliary qubits, while the Bell states keep unchanged. One can read out the information by detecting the auxiliary qubits. Thus the Bell-state analysis is nondestructive. The numerical simulations show that the protocol possesses high success probability of distinguishing each Bell state with current experimental technology even when decoherence is taken into account. Thus, the protocol may have potential applications for the information readout in quantum communications and quantum computations in superconducting quantum networks.