<< Back to Program

Plenaries

Keynotes

Posters

TOPICS

Optomechanics

  • Thursday 4 
  • 13:20
  • - 13:50 
  • 1401 
  • Talk # 1 
  • Session # 3

Coherent polaromechanical control of exciton-polariton condensation in microcavities

Alexander Kuznetsov1, Ignacio Carraro-Haddad2,3, Gonzalo Usaj2,3, Klaus Biermann1, Alejandro Fainstein2,3, Paulo Santos1

  • 1- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5-7, 10117 Berlin, Germany
  • 2- Bariloche Atomic Centre and Balseiro Institute, National Council for Scientific and Technical Research, 8400 S.C. de Bariloche, R.N., Argentina
  • 3- Institute of Nanoscience and Nanotechnology, National Council for Scientific and Technical Research, 8400 Bariloche, Argentina

Presenting Author:

  • Alexander
  • Kuznetsov

kuznetsov@pdi-berlin.de

Engineered coupling between optical, electronic and vibrational degrees of freedom in semiconductor structures opens a pathway to manipulate light-matter interactions at the nanoscale. On the one hand, excitons can couple strongly to resonant photons, resulting in light-matter exciton-polariton quasiparticles. On the other hand, lattice phonons can couple efficiently to excitons via the deformation potential mechanism. Moreover, interactions between phonons, excitons and photons can be enhanced in semiconductor microcavities (MCs). This enables a novel a field of polaromechanics1, which studies interactions between non-equilibrium exciton-polariton Bose-Einstein-like condensates (BECs)2 and GHz phonons in hybrid phonon-photon MCs3. Polaromechanical MCs are a powerful platform to study phonon lasing4, phonoritons5, locking6 and time crystals7.

In this talk, we will address one of the challenges related to the tunable coherent population transfer in quantum systems on the timescale comparable to their microscopic coherence in the context of polariton BECs. Specifically, we demonstrate very precise and tunable control of the gain and loss, and therefore the population distribution within confined multimode polariton BEC system using an acoustic Floquet modulation. We use an (Al,Ga)As patterned MC that hosts spatially confined multimode polariton BEC8 and show that the BEC population can be selectively transferred between confined levels by modulating the excitonic BEC component by the strain of a piezoelectrically excited GHz bulk acoustic wave9,10. For large-enough acoustic amplitudes, the bare exciton energy is periodically swept through all of the confined photonic levels, which leads to the periodic passage through multiple avoided crossings. As our experiments and the accompanying theory show, an interplay between the bosonic stimulation and the adiabatic Landau-Zener-like population transfer leads, for large enough modulation amplitudes, to the ground state BEC and the emission of coherent sub-50 ps pulses in the time domain and frequency combs in the spectral domain11. The demonstrated results are relevant for tunable ultrafast pulsed laser-like emission for novel information technologies.

  1. Santos & Fainstein, Opt. Mater. Express 13, 1974–1983 (2023)
  2. Kasprzak et al., Nature 443, 409–414 (2006)
  3. Fainstein et al., Phys. Rev. Lett. 110, 037403 (2013)
  4. Chafatinos et al., Nat. Commun. 11, 4552 (2020)
  5. Kuznetsov et al.,  Nat. Commun. 14, 5470 (2023)
  6. Chafatinos et al.,  Nat. Commun. 14, 3485 (2023)
  7. Haddad et al., Science 384, 995–1000 (2024)
  8. Kuznetsov et al.,  Phys. Rev. B 97, 195309 (2018)
  9. Machado et al., Phys. Rev. Appl. 12, 1–14 (2019)
  10. Kuznetsov et al., Phys. Rev. X 11, 021020 (2021)
  11. Kuznetsov et al., arXiv:2506.05874v1 (2025)