Long-Distance Coupling and Energy Transfer between Exciton States in Magnetically Controlled Microcavities

TL;DR

This paper demonstrates long-distance energy transfer between excitonic states in microcavities, enabled by polariton coupling and magnetic tuning, surpassing traditional short-range interaction limits in quantum emitters.

Contribution

It introduces a method for long-range exciton coupling via microcavity polaritons, controlled by magnetic fields, advancing quantum network scalability.

Findings

Energy transfer over 2 micrometers achieved

Magnetic field tuning controls transfer direction

Long-distance coupling surpasses 10 nm limit

Abstract

Coupling of quantum emitters in a semiconductor relies, generally, on short-range dipole-dipole or electronic exchange type interactions. Consistently, energy transfer between exciton states, that is, electron-hole pairs bound by Coulomb interaction, is limited to distances of the order of 10~nm. Here, we demonstrate polariton-mediated coupling and energy transfer between excitonic states over a distance exceeding 2~$\mu$m. We accomplish this by coupling quantum well-confined excitons through the delocalized mode of two coupled optical microcavities. Use of magnetically doped quantum wells enables us to tune the confined exciton energy by the magnetic field and in this way to control the spatial direction of the transfer. Such controlled, long-distance interaction between coherently coupled quantum emitters opens possibilities of a scalable implementation of quantum networks and quantum simulators based on solid-state, multi-cavity systems.