• Publications
  • Influence
Sub-cycle switch-on of ultrastrong light–matter interaction
This work uses a quantum-well waveguide structure to optically tune light–matter interaction from weak to ultrastrong and turn on maximum coupling within less than one cycle of light, and directly monitors how a coherent photon population converts to cavity polaritons during abrupt switching.
Breakdown of gauge invariance in ultrastrong-coupling cavity QED
We revisit the derivation of Rabi- and Dicke-type models, which are commonly used for the study of quantum light-matter interactions in cavity and circuit QED. We demonstrate that the validity of the
Signatures of the ultrastrong light-matter coupling regime
In a microcavity, light-matter coupling is quantified by the vacuum-Rabi frequency ?R. When ?R is larger than radiative and nonradiative loss rates, the system eigenstates (polaritons) are linear
Ultrastrong coupling between a cavity resonator and the cyclotron transition of a two-dimensional electron gas in the case of an integer filling factor
We investigate theoretically the coupling between a cavity resonator and the cyclotron transition of a two-dimensional electron gas under an applied perpendicular magnetic field. We derive and
Light-matter decoupling in the deep strong coupling regime: the breakdown of the Purcell effect.
Improvements in both the photonic confinement and the emitter design have led to a steady increase in the strength of the light-matter coupling in cavity quantum electrodynamics experiments. This has
Quantum theory of intersubband polarons
We present a microscopic quantum theory of intersubband polarons, quasiparticles originated from the coupling between intersubband transitions and longitudinal optical phonons. To this aim, we
Virtual photons in the ground state of a dissipative system
Much of the novel physics predicted to be observable in the ultrastrong light–matter coupling regime rests on the hybridisation between states with different numbers of excitations, leading to a
Open quantum systems with local and collective incoherent processes: Efficient numerical simulations using permutational invariance
The permutational invariance of identical two-level systems allows for an exponential reduction in the computational resources required to study the Lindblad dynamics of coupled spin-boson ensembles
Terahertz lasing from intersubband polariton-polariton scattering in asymmetric quantum wells
Electric dipole transitions between different cavity polariton branches or between dressed atomic states with the same excitation number are strictly forbidden in centro-symmetric systems. For doped
Ultrastrong light-matter coupling at terahertz frequencies with split ring resonators and inter-Landau level transitions
We study strong light-matter coupling at terahertz frequencies employing a system based on an array of deeply subwavelength split ring resonators deposited on top of an ensemble of modulation-doped