Kardar-Parisi-Zhang universality in 1D exciton-polariton systems

Statistical Physics and Complexity Group meeting

Kardar-Parisi-Zhang universality in 1D exciton-polariton systems

  • Event time: 11:30am until 12:30pm
  • Event date: 14th April 2021
  • Speaker: Prof Leonie Canet (University Grenoble Alpes)
  • Location: Online - see email

Event details

Exciton-polaritons are bosonic short-lived quasiparticles which are created in a semiconductor quantum well under optical pumping,  where they arise from the strong-coupling of excitons (electron-hole excitations) and of the photons trapped in the micro-cavity. They behave collectively as a quantum fluid, which is genuinely out-of-equilibrium  because of its driven-dissipative nature.  They were shown to exhibit the non-equilibrium analogue of a Bose-Einstein condensation, where a large fraction of the bosons condense into a single quantum state. Recently, an unexpected connection has been unveiled between the statistical properties of the phase of the one-dimensional exciton-polariton condensate and the ones of a stochastically growing interface, described by the  Kardar-Parisi-Zhang (KPZ) equation. In this talk, I will further explore this connection, and show that it extends well beyond the mere KPZ scaling exponents. I will study in details the statistics of the fluctuations of the phase of the condensate, and show that by tailoring an appropriate confinement potential for the polaritons, different geometrical universality sub-classes, well-known for the KPZ interface, can be realized in this system. I will show in particular that the fluctuations of the phase follow the expected Tracy-Widom GOE, or GUE distributions, and that their two-point correlations follow the corresponding Airy processes. These results are based on numerical simulations of the generalized Gross-Pitaevskii equation describing the exciton-polariton condensate with realistic experimental parameters, indicating that all the KPZ features are indeed observable in current experimental set-ups.