Acoustic spin resonance in polariton condensates

TL;DR

This paper theoretically explores how acoustic waves can resonantly control the pseudospin dynamics in polariton condensates, revealing nonlinear effects, hysteresis, and switchable states.

Contribution

It introduces the concept of acoustic spin resonance in polariton condensates and analyzes its nonlinear and dissipative behaviors under various conditions.

Findings

Resonant polarization oscillations are driven by transverse acoustic waves.

Spin-dependent interactions cause nonlinear line shapes and resonance shifts.

Amplitude hysteresis and bistability emerge due to gain, reservoir dynamics, and spin relaxation.

Abstract

We theoretically investigate acoustic spin resonance in a spatially homogeneous spinor polariton condensate. A longitudinal acoustic wave generates a time-periodic strain-induced effective magnetic field acting on the condensate pseudospin. When this field is transverse to the static in-plane linear-polarization splitting, it resonantly drives polarization oscillations. We show that spin-dependent interactions shift the resonance and produce nonlinear line shapes, while gain, reservoir dynamics, and spin relaxation make the response dissipative and history-dependent, producing amplitude hysteresis. In the presence of lifetime anisotropy, the condensate can develop a bifurcated stationary state with finite circular polarization, and a resonant acoustic drive can switch between the corresponding out-of-plane branches. A Zeeman splitting provides an additional conservative knob for tuning the resonance frequency. Our results identify coherent acoustic driving as a route to resonant, nonlinear, and switchable control of polariton pseudospin dynamics.