Ultrastrong Light–Matter Coupling in Deeply Subwavelength THz LC Resonators

• DOI: 10.1021/acsphotonics.8b01778
• Publication Date: 2019-04-02T16:40:44Z
• Authors: Mathieu Jeannin; Giacomo Mariotti ...; Stéphan Suffit; Djamal Gacemi; Angela Vasanelli; Lianhe Li; Alexander Giles D...; Edmund Linfield; Carlo Sirtori; Yanko Todorov
• Keywords: Capacitive coupling

The ultra-strong light-matter coupling regime has been demonstrated in a novel three-dimensional inductor-capacitor (LC) circuit resonator, embedding semiconductor two-dimensional electron gas the capacitive part. fundamental resonance of LC interacts with intersubband plasmon excitation at $\omega_c = 3.3$~THz normalized strength $2\Omega_R/\omega_c 0.27$. Light matter interaction is driven by quasi-static electric field capacitors, and takes place highly subwavelength effective volume $V_{\mathrm{eff}} 10^{-6}\lambda_0^3$ . This enables observation $2.4\times10^3$ electrons only. Notably, our fabrication protocol can be applied to integration region into arbitrary nano-engineered three dimensional meta-atoms. architecture considered building block metamaterials for ultra-low dark current detectors.