Adiabatic information transport in the presence of decoherence

TL;DR

This paper investigates adiabatic quantum transport's robustness against decoherence, revealing that while population transfer remains stable, spatial superpositions are highly fragile under realistic noise conditions.

Contribution

It models the effects of both Markovian and non-Markovian decoherence on adiabatic quantum transport, highlighting the differential robustness of population versus superposition transport.

Findings

Decoherence rate plateaus with increasing spatial separation.

Population transport remains robust despite noise.

Spatial superpositions are highly fragile under decoherence.

Abstract

We study adiabatic population transfer between discrete positions. Being closely related to STIRAP in optical systems, this transport is coherent and robust against variations of experimental parameters. Thanks to these properties the scheme is a promising candidate for transport of quantum information in quantum computing. We study the effects of spatially registered noise sources on the quantum transport and in particular model Markovian decoherence via non-local coupling to nearby quantum point contacts which serve as information readouts. We find that the rate of decoherence experienced by a spatial superposition initially grows with spatial separation but surprisingly then plateaus. In addition we include non-Markovian effects due to couplings to nearby two level systems and we find that although the population transport exhibits robustness in the presence of both types of noise sources, the transport of a spatial superposition exhibits severe fragility.