Decoherence of the hybrid qubit in a double quantum dot

Key Laboratory of Quantum Information, Chinese Academy of Sciences, University of Science and Technology of China - Hefei, Anhui 230026, China and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China - Hefei, Anhui 230026, China

^(a) qinxk@mail.ustc.edu.cn

Received: 8 March 2016
Accepted: 13 May 2016

Abstract

We study decoherence of the hybrid qubit in a double quantum dot system which exhibits the longest decoherence time in the large bias region rather than at the avoided crossing conventionally considered the sweet spot for decoherence performance. Using a three-level model, we analyze how the characteristics of the spectrum of the system dictate its decoherence properties, and confirm our conclusions quantitatively by calculating the decoherence performance of the system and comparing the results with experimental data.