Room-temperature polariton quantum fluids in halide perovskites

Abstract

Quantum fluids exhibit quantum mechanical effects at the macroscopic level, which contrast strongly with classical fluids. Gain-dissipative solid-state exciton-polaritons systems are promising emulation platforms for complex quantum fluid studies at elevated temperatures. Recently, halide perovskite polariton systems have emerged as materials with distinctive advantages over other room-temperature systems for future studies of topological physics, non-Abelian gauge fields, and spin-orbit interactions. However, the demonstration of nonlinear quantum hydrodynamics, such as superfluidity and Čerenkov flow, which is a consequence of the renormalized elementary excitation spectrum, remains elusive in halide perovskites. Here, using homogenous halide perovskites single crystals, we report, in both one- and two-dimensional cases, the complete set of quantum fluid phase transitions from normal classical fluids to scatterless polariton superfluids and supersonic fluids—all at room temperature, clear consequences of the Landau criterion. Specifically, the supersonic Čerenkov wave pattern was observed at room temperature. The experimental results are also in quantitative agreement with theoretical predictions from the dissipative Gross-Pitaevskii equation. Our results set the stage for exploring the rich non-equilibrium quantum fluid many-body physics at room temperature and also pave the way for important polaritonic device applications.

Exciton Polaritons in Emergent Two-Dimensional Semiconductors

“…194 In this way, the Berry curvature of the polariton bands can be quantitatively controlled by electrically tuning the orientations of the liquid crystal. The local Berry curvature is found to be nonzero, but the integral Berry curvature remains zero since the time-reversal symmetry is not broken, which is similar to those discovered in anisotropic 3D perovskites 195,196 and anisotropic organic molecule. 197 The other example introduces a Zeeman effect via an external magnetic field in an anisotropic polariton system of FP cavity, which leverages full advantages of the anisotropic 2DPK.…”

“…By controlling the relative angle θ from π/2 to 0, a transition from the weak light-matter coupling to strong coupling regimes can be observed (Figure b,c, and see simulation details in Methods). Furthermore, combining room-temperature polariton condensation and superfluid phenomena in perovskites , with the ultralow condensation threshold with BIC structures could significantly improve device performance, offering a distinct opportunity to develop electrically pumped polariton condensation and lasers in perovskite . Because 2D AFM excitons can exhibit long-range spin ordering and magnons, exciton polaritons could exhibit more unconventional quantum phenomena and attractive optoelectronic devices by taking advantages of the nonreciprocity of magnons and exploring their excitonic coupling with magnons under the external magnetic field.…”

Room‐Temperature Exceptional‐Point‐Driven Polariton Lasing from Perovskite Metasurface

“…[26,27] Moreover, its outstanding physical properties such as relatively high exciton binding energy and oscillator strength, [28] as well as high defect tolerance, [29] allow for realizing a strong light-matter coupling regime in photonic cavities and even non-equilibrium polariton Bose-Einstein condensation at room temperature. [9,10,[30][31][32][33] Moreover, solution-based methods of synthesis, combined with a high refractive index of the synthesized materials, and their scalable nanostructuring techniques, such as direct laser ablation, [34] nanoimprint lithogrpahy, [35] and self-assembly methods, [36] open the way to apply them in planar metasurfaces, supporting high-Q polariton states and avoiding vertical Bragg cavities. [36][37][38][39] Although the perovskites were used in different laser designs [40] including surface-emitting distributed feedback lasers, [41][42][43] while polariton lasing in halide perovskite metasurfaces has not been yet observed experimentally.…”

Polaritonic and Excitonic Semiclassical Time Crystals based on TMDC strips in an external periodic potential

“…The lower polaritons can form Bose-Einstein condensates [23]. One such condensate has been recently verified in room-temperature settings [27].…”

“…The critical temperature is relatively high because the 2D thermal de Broglie wavelength is inversely proportional to the mass of the quasiparticle, and this wavelength becomes comparable to the distance between the bosons. BEC and superfluidity of exciton-polaritons have been observed in a microcavity [25][26][27]. The various applications of microcavity polaritons for optoelectronics and nanophotonics have been developed recently [23].…”