Speaker:  Prof. Shin-Tza Wu, National Chung Cheng University

Time: 1:20PM, 06/07, 2021

Title: 
Quantum-walk approach to the GKP encoding

Google Meet link : 
https://meet.google.com/hqz-wqjz-gmi
(AMO Seminar 20210607)

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 walk 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.