Vibrational exciton-mediated quantum state transfert: a simple model

TL;DR

This paper proposes a quantum communication protocol where vibrational excitons mediate high-fidelity quantum state transfer between distant molecular systems, with minimized decoherence across various temperatures.

Contribution

It introduces an exactly solvable model of exciton-phonon interactions that enables efficient quantum state transfer with constructive interference effects.

Findings

High-fidelity transfer achieved over broad temperature range

Constructive interference enhances tunneling paths

Exact solution validates perturbation theory results

Abstract

A communication protocol is proposed in which quantum state transfer is mediated by a vibrational exciton. We consider two distant molecular groups grafted on the sides of a lattice. These groups behave as two quantum computers where the information in encoded and received. The lattice plays the role of a communication channel along which the exciton propagates and interacts with a phonon bath. Special attention is paid for describing the system involving an exciton dressed by a single phonon mode. The Hamiltonian is thus solved exactly so that the relevance of the perturbation theory is checked. Within the nonadiabatic weak-coupling limit, it is shown that the system supports three quasi-degenerate states that define the relevant paths followed by the exciton to tunnel between the computers. When the model parameters are judiciously chosen, constructive interferences take place between these paths. Phonon-induced decoherence is minimized and a high-fidelity quantum state transfer occurs over a broad temperature range.