Absorption Engineering in an Ultrasubwavelength Quantum System

Mathieu Jeannin (1) , Thomas Bonazzi (1) , Djamal Gacemi (1) , Angela Vasanelli (1) , Lianhe Li (2) , Alexander Giles Davies (2) , Edmund Linfield (2) , Carlo Sirtori (1) , Yanko Todorov (1)

1 QUAD : Physique Quantique et Dispositifs
2 School of Electronic and Electrical Engineering [Leeds]

Many photonic and plasmonic structures have been proposed to achieve ultra-subwavelength light confinement across the electromagnetic spectrum. Notwithstanding this effort, however, the efficient funneling of external radiation into nano-scale volumes remains problematic. Here we demonstrate a photonic concept that fulfills the seemingly incompatible requirements for both strong electromagnetic confinement and impedance matching to free space. Our architecture consists of antenna-coupled meta-atom resonators that funnel up to 90% of the incident radiation into an ultra subwavelength semiconductor quantum well absorber of volume V= λ310-6. A significant fraction of the coupled electromagnetic energy is used to excite the electronic transitions in the quantum well, with photon absorption efficiency 550 times larger than the intrinsic value of the electronic dipole. This system opens important perspectives for ultra-low dark current quantum detectors and for the study of light-matter interaction in the extreme regimes of electronic and photonic confinement.

Mots clés: nanoscale absorbers; metamaterials; optical antennas; strong light-matter coupling

Domaines: Optique [physics.optics]; Autre [cond-mat.other]; Physique Quantique [quant-ph]

Mathieu Jeannin, Thomas Bonazzi, Djamal Gacemi, Angela Vasanelli, Lianhe Li, et al.. Absorption Engineering in an Ultrasubwavelength Quantum System. Nano Letters, 2020, 20 (6), pp.4430-4436. ⟨10.1021/acs.nanolett.0c01217⟩. ⟨hal-02784734⟩