Observation of a Quantized Vortex Vanishing in Exciton-Polariton Superfluids

In semiconductor microcavity, exciton-polaritons are bosonic quasi-particles that can create a quantized vortex by Laguerre-Gaussian (LG) pump laser. Here, we report an observation of a vanishment of a quantized vortex in exciton-polariton superfluids. In a non-resonant LG pump laser, polariton condensates can be confined under the optical potential, resulting in multistate condensates consisting of a rotating excited state and a stationary ground state. In time-resolved spectroscopy with pulsed excitation, we observed that the excited state, a polariton vortex, decayed to the ground state over time. Furthermore, our experimental results are in excellent agreement with the theoretical calculations employing the driven-dissipative Gross–Pitaevskii equation coupled with pumping reservoirs.