On the effect of decoherence on quantum tunnelling

TL;DR

This paper explores how decoherence influences quantum tunnelling, proposing experiments to measure decoherence effects indirectly through tunnelling rates, and analyzes different regimes to distinguish intrinsic and environment-induced decoherence.

Contribution

It introduces a framework for examining decoherence effects on quantum tunnelling and derives formulas linking tunnelling rates with various decoherence regimes.

Findings

Decoherence affects tunnelling rates in distinguishable ways.

Intrinsic and environment-induced decoherence can be experimentally differentiated.

Formulas relate tunnelling rates to decoherence parameters.

Abstract

This work proposes a series of quantum experiments that can, at least in principle, allow for examining microscopic mechanisms associated with decoherence. These experiments can be interpreted as a quantum-mechanical version of non-equilibrium mixing between two volumes separated by a thin interface. One of the principal goals of such experiments is in identifying non-equilibrium conditions when time-symmetric laws give way to time-directional, irreversible processes, which are represented by decoherence at the quantum level. The rate of decoherence is suggested to be examined indirectly, with minimal intrusions -- this can be achieved by measuring tunnelling rates that, in turn, are affected by decoherence. Decoherence is understood here as a general process that does not involve any significant exchanges of energy and governed by a particular class of the Kraus operators. The present work analyses different regimes of tunnelling in the presence of decoherence and obtains formulae that link the corresponding rates of tunnelling and decoherence under different conditions. It is shown that the effects on tunnelling of intrinsic decoherence and of decoherence due to unitary interactions with the environment are similar but not the same and can be distinguished in experiments.