Controllable fusion of electromagnetic bosons in two-dimensional semiconductors

TL;DR

This paper introduces a method to controllably fuse electromagnetic bosons like excitons in 2D semiconductors using anisotropy and magnetic tuning, enabling quantum reactions and entangled molecules.

Contribution

It presents a novel physical principle for resonant fusion of bosons in 2D semiconductors through anisotropy and magnetic control, leading to new quantum states.

Findings

Resonant amplification of boson scattering near biexciton energy.

Prediction of giant, entangled molecules (Feshbach dimers) from biexcitons.

Potential applications in strongly-correlated photonics and quantum chemistry.

Abstract

We propose a physical principle for implementation of controllable interactions of identical electromagnetic bosons (excitons or polaritons) in two-dimensional (2D) semiconductors. The key ingredients are tightly bound biexcitons and in-plane anisotropy of the host structure due to, e.g., a uniaxial strain. We show that anisotropy-induced splitting of the radiative exciton doublet couples the biexciton state to continua of boson scattering states. As a result, two-body elastic scattering of bosons may be resonantly amplified when energetically tuned close to the biexciton by applying a transverse magnetic field or tuning the coupling with the microcavity photon mode. At the resonance, bosonic fields undergo quantum reaction of fusion accompanied by their squeezing. For excitons, we predict giant molecules (Feshbach dimers) which can be obtained from a biexciton via rapid adiabatic sweeping of the magnetic field across the resonance. The molecules possess non-trivial entanglement properties. Our proposal holds promise for the strongly-correlated photonics and quantum chemistry of light.