Decoherence of a Single Qubit from Quantum Anomaly

TL;DR

This paper demonstrates that quantum anomalies can induce decoherence in a single qubit through intrinsic phase relaxation, independent of environmental interactions, by affecting the Hamiltonian's self-adjointness.

Contribution

It provides an explicit example showing how quantum anomalies can cause decoherence in a single qubit, highlighting a novel intrinsic decoherence mechanism.

Findings

Quantum anomalies can lead to decoherence without environmental interaction.

The Hamiltonian becomes non-self-adjoint due to anomalies, causing phase relaxation.

Decoherence originates from the system's intrinsic dynamics, not external noise.

Abstract

We show via an explicit example that quantum anomalies can lead to decoherence of a single quantum qubit through phase relaxation. The anomaly causes the Hamiltonian to develop a non-self-adjoint piece due to the non-invariance of the domain of the Hamiltonian under symmetry transformation. The resulting decoherence originates completely from the dynamics of the system itself and not, as usually considered, from interactions with the environment.