Quantum emitter interacting with a h -BN layer in the strong-coupling regime

Abstract

We present that the hexagonal boron nitride ($h$-BN) layer is a platform that facilitates strong light-matter interactions. We calculate the emission spectrum of a quantum emitter (QE) interacting with the $h$-BN layer at the strong-coupling regime. The $h$-BN layer supports phonon polariton modes at the far-infrared part of the spectrum that lead to a ${10}^{4}$ confinement of light. The phonon polaritons are the main channel of relaxation of the QE, where the Purcell factor of the QE shows an enhancement of the relaxation rate above three orders of magnitude, compared to the free space value, when it is placed $100\phantom{\rule{0.28em}{0ex}}\mathrm{nm}$ above the $h$-BN layer. At smaller separation distances of the QE with the $h$-BN layer the total system operates in the strong-coupling regime, which appears as two peaks in the emission spectrum, splitting the single emission peak of the QE emitting in the free space. This energy splitting is the Rabi splitting $\ensuremath{\hbar}\mathrm{\ensuremath{\Omega}}$ that depends on the transition energy $\ensuremath{\hbar}{\ensuremath{\omega}}_{0}$ of the QE, the position and the free-space relaxation rate of the QE, reaching values of $\mathrm{\ensuremath{\Omega}}/{\ensuremath{\omega}}_{0}=23.5%$.