Acoustic spin resonance in polariton condensates
Phys. Rev. B 114, 285301 – Published 5 November, 2026
DOI: https://doi.org/10.1103/3s7p-njz5
Abstract
We theoretically investigate acoustic spin resonance in a spatially homogeneous spinor polariton condensate. A longitudinal acoustic wave with a suitable in-plane anisotropic strain component generates a time-periodic strain-induced effective magnetic field acting on the condensate pseudospin. In contrast to the usual scalar acoustic modulation of the polariton energy, the anisotropic part of the strain response acts as an ac in-plane effective magnetic field in polarization space. 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 finite-rate amplitude-cycle hysteresis under the stated protocol. In the presence of lifetime anisotropy, the condensate can develop a bifurcated stationary state with finite circular polarization, and a frequency-selective acoustic protocol can reverse the circular polarization of a condensate prepared on one undriven branch and transfer it to an opposite- driven state. 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.
