Decoherence of Topological Qubit in Linear and Circular Motions: Decoherence Impedance, Anti-Unruh and Information Backflow

TL;DR

This paper investigates how a topological qubit composed of Majorana zero modes decoheres under linear and circular motions, revealing anti-Unruh effects, decoherence impedance, and information backflow, with implications for quantum coherence preservation.

Contribution

It provides an exact analysis of decoherence patterns in non-inertial motions, highlighting anti-Unruh phenomena and coherence preservation due to nonlocality of topological qubits.

Findings

Decoherence rate is anti-correlated with acceleration at short times.

Information backflow occurs with modulated coupling or acceleration.

Incoherent acceleration can preserve coherence of Majorana modes.

Abstract

In this paper, we consider the decoherence patterns of a topological qubit made of two Majorana zero modes in the generic linear and circular motions in the Minkowski spacetime. We show that the reduced dynamics is exact without Markov approximation. Our results imply that the acceleration will cause thermalization as expected by Unruh effect. However, for the short-time scale, we find the rate of decoherence is anti-correlated with the acceleration, as kind of decoherence impedance. This is in fact related to the "anti-Unruh" phenomenon previously found by studying the transition probability of Unruh-DeWitt detector. We also obtain the information backflow by some time modulations of coupling constant or acceleration, which is a characteristic of the underlying non-Markovian reduced dynamics. Moreover, by exploiting the nonlocal nature of the topological qubit, we find that some incoherent accelerations of the constituent Majorana zero modes can preserve the coherence instead of thermalizing it.