Scalable ultra-strong light–matter coupling at THz frequencies using graded alloy parabolic quantum wells
We demonstrate scalable ultra-strong light–matter coupling with intersubband polaritons in a truly harmonic confining potential. The harmonicity grants immunity from electron–electron interactions, a protection guaranteed by the Kohn theorem, allowing the intersubband transition frequency to be lowered while keeping the light–matter interaction strength constant. In principle, this procedure permits increasing the relative coupling strength (η = ΩRabi/ω12) at will. We measure a record low intersubband transition at 1.24 THz and a lower polaritonic mode at 920 GHz, below the barrier of 1 THz. The system exhibits a η ratio of 0.24, fully in the ultra-strong coupling regime, and remains stable up to 78 K. This approach is valuable for future non-adiabatic quantum electrodynamic experiments at long wavelengths.
Authors
- T. Blaikie (ORCID: https://orcid.org/0009-0005-4479-8979)
- Paul Goulain (ORCID: https://orcid.org/0000-0002-3546-8418)
- A. Wright (ORCID: https://orcid.org/0000-0002-5953-4221)
- M. Mičica
- Z. R. Wasilewski (ORCID: https://orcid.org/0000-0001-7116-5863)
- Stefano Pirotta
- Mathieu Jeannin (ORCID: https://orcid.org/0000-0001-8878-8960)
- Anna De Vetter (ORCID: https://orcid.org/0009-0007-9783-427X)
- Chris Deimert (ORCID: https://orcid.org/0000-0002-8362-4198)
- R. Colombelli (ORCID: https://orcid.org/0000-0002-1540-9920)
- Jean‐Michel Manceau (ORCID: https://orcid.org/0000-0002-8873-832X)
- S. Dhillon (ORCID: https://orcid.org/0000-0002-5487-9570)
Institutions
- Centre National de la Recherche Scientifique (FR)
- University of Waterloo (CA)
- Université Paris Cité (FR)
- Université Paris Sciences et Lettres (FR)
- Université Paris-Saclay (FR)
- Sorbonne Université (FR)
- Sorbonne Paris Cité (FR)
- Centre de Nanosciences et de Nanotechnologies (FR)
Publication Details
- Journal
- Applied Physics Letters
- Published
- 2024-10-07
- DOI
- https://doi.org/10.1063/5.0225733
- Citations
- 1
- Primary Topic
- Strong Light-Matter Interactions
- Type
- article
- Field-Weighted Citation Impact
- 0.34
Funders
- European Commission
- HORIZON EUROPE European Research Council