Quantum decoherence by Coulomb interaction

N Kerker,A Pooch,A Stibor,L M Steinert,R Röpke

doi:10.1088/1367-2630/ab8efc

Abstract

The performance of modern quantum devices in communication, metrology or microscopy relies on the quantum–classical interaction which is generally described by the theory of decoherence. Despite the high relevance for long coherence times in quantum electronics, decoherence mechanisms mediated by the Coulomb force are not well understood yet and several competing theoretical models exist. Here, we present an experimental study of the Coulomb-induced decoherence of free electrons in a superposition state in a biprism electron interferometer close to a semiconducting and metallic surface. The decoherence was determined through a contrast loss at different beam path separations, surface distances and conductibilities. To clarify the current literature discussion, four theoretical models were compared to our data. We could rule out three of them and got good agreement with a theory based on macroscopic quantum electrodynamics. The results will enable the determination and minimization of specific decoherence channels in the design of novel quantum instruments.

Highlights

The performance of modern quantum devices in communication, metrology or microscopy relies on the quantum-classical interaction which is generally described by the theory of decoherence
Despite the high relevance for long coherence times in quantum electronics, decoherence mechanisms mediated by the Coulomb force are not well understood yet and several competing theoretical models exist
To determine the role of decoherence by Coulomb interaction, an experiment was proposed by Anglin et al [5, 31] and performed by Sonnentag et al [12, 32] where electrons are interfered in an biprism interferometer

Summary

Introduction

The performance of modern quantum devices in communication, metrology or microscopy relies on the quantum-classical interaction which is generally described by the theory of decoherence. The decoherence was determined through a contrast loss at different beam path separations, surface distances and conductibilities. To determine the role of decoherence by Coulomb interaction, an experiment was proposed by Anglin et al [5, 31] and performed by Sonnentag et al [12, 32] where electrons are interfered in an biprism interferometer.

Results

Conclusion