Ultrastrong Coupling in the Near-field of Complementary Split Ring Resonators

TL;DR

This paper demonstrates ultrastrong light-matter coupling in complementary split ring resonators, achieving record high normalized coupling rates and observing polariton blue-shifts due to diamagnetic effects.

Contribution

It reports the first observation of ultrastrong coupling in complementary split ring resonators with record normalized coupling rates up to 0.87.

Findings

Record high normalized coupling rate of 0.87 achieved.

Blue-shift of polaritons observed due to diamagnetic term.

Ultrastrong coupling demonstrated in both metallic and superconducting resonators.

Abstract

The ultrastrong light-matter interaction regime was investigated in metallic and superconducting complementary split ring resonators coupled to the cyclotron transition of two dimensional electron gases. The sub-wavelength light confinement and the large optical dipole moment of the cyclotron transition yield record high normalized coupling rates of up to $\frac{\Omega_R}{\omega_c}=$ 0.87. We observed a blue-shift of both polaritons due to the diamagnetic term of the interaction Hamiltonian.