Non-adiabatic stripping of a cavity field from electrons in the deep-strong coupling regime

Abstract

Atomically strong light pulses can drive sub-optical-cycle dynamics. When the Rabi frequency – the rate of energy exchange between light and matter – exceeds the optical carrier frequency, fascinating non-perturbative strong-field phenomena emerge, such as high-harmonic generation and lightwave transport. Here, we explore a related novel subcycle regime of ultimately strong light-matter interaction without a coherent driving field. We use the vacuum fluctuations of nanoantennas to drive cyclotron resonances of two-dimensional electron gases to vacuum Rabi frequencies exceeding the carrier frequency. Femtosecond photoactivation of a switch element inside the cavity disrupts this ‘deep-strong coupling’ more than an order of magnitude faster than the oscillation cycle of light. The abrupt modification of the vacuum ground state causes spectrally broadband polarisation oscillations confirmed by our quantum model. In the future, this subcycle shaping of hybrid quantum states may trigger cavity-induced quantum chemistry, vacuum-modified transport, or cavity-controlled superconductivity, opening new scenarios for non-adiabatic quantum optics.

Collective theory for an interacting solid in a single-mode cavity

“…The derivation of the collective theory relies solely on a linear coupling between light and matter, so it should generally apply to order parameters such as incommensurate charge density wave or exciton condensates, which couple linearly to light. Moreover, the collective theory should be useful to compute the dynamic nonlinear response and higher order photon correlation functions in the cavity (extending on the description of linear response of strongly coupled light-matter hybrids 44), and to interpret nonadiabatic QED experiments [45].…”

Cavity-mediated electron hopping in disordered quantum Hall systems

“…In particular, such a regime was predicted for the coupling of the cyclotron transition of a 2D electron gas to a cavity mode [11] and experimentally demonstrated by using deeply subwavelength THz split-ring resonators [12]. Interesting linear and nonlinear optical properties of the related Landau polaritons have been investigated in a recent series of experimental spectroscopy works [13][14][15][16][17][18]. Other investigations have instead exploited optics as a probe of electronic quantum Hall physical properties [19][20][21][22], or optical pumping as a way to manipulate electronic quantum Hall states [23].…”

Theoretical proposals to measure resonator-induced modifications of the electronic ground state in doped quantum wells

“…One problem with this idea is that we need to consider a modulated, time-dependent system, in analogy with the dynamical Casimir effect [35][36][37], and similarly sensitive to the density of dressed states, not to the presence of vacuum excitations. A second problem is that, in order to achieve non-vanishing emission, perturbation frequencies of the order of the bare optical frequency are necessary [38,39], a requirement which has until now thwarted any attempt to observe vacuum excitations. This paper explores a novel approach to these problems, by noticing that cavity-induced virtual electronic excitations do modify the ground-state charge distribution, and they can thus be measured exploiting already well-tested methods used to map charge distributions in nanoscopic systems without requiring any nonadiabatic modulation.…”