Quantum walk finds a way for GKP!

  • Event Date: 2021-12-17
  • Speaker: Shin-Tza Wu (Associate Professor, Department of Physics, National Chung Cheng University)  /  Host:
    Place: Rm104, Chin-Pao Yang Lecture Hall, CCMS & New Physics Building, NTU

Title:Quantum walk finds a way for GKP!
Time:2021/12/17 (Fri.) 14:30
Place:Rm104, Chin-Pao Yang Lecture Hall, CCMS & New Physics Building, NTU

Abstract:
In this talk, I will present a theoretical framework for encoding arbitrary logical states of a quantum bit into a continuous-variable quantum mode through quantum walks. Starting with a squeezed-vacuum state of the quantum mode, I will explain how quantum walks of the state in phase space can generate codewords that are variants of those proposed originally by Gottesman, Kitaev, and Preskill (GKP) [Phys. Rev. A 64 , 012310 (2001)]. In particular, with a coin-toss transformation that projects the quantum coin onto diagonal coin-state, the resulting nonunitary quantum walks can generate codewords akin to the prototypical GKP ones. Surprisingly, even without optimization, it is found that these codewords can outperform their GKP counterparts in error corrections by a narrow margin. Possible experimental realizations of this encoding scheme through circuit quantum electrodynamics systems will also be discussed.