Quantum magneto-electrodynamics of electrons embedded in a photon cavity

Abstract

We investigate the coupling between a quantized electromagnetic field in a cavity resonator and a Coulomb interacting electronic system in a nanostructure in an external magnetic field. The effects caused by the geometry of the electronic system and the polarization of the electromagnetic field are explicitly taken into account. Our numerical results demonstrate that the twolevel system approximation and the Jaynes-Cummings model remain valid in the weak electron-photon coupling regime, while the quadratic vector potential in the diamagnetic part of the charge current leads to significant correction to the energy spectrum in the strong coupling regime. Furthermore, we find that coupling to a strong cavity photon mode polarizes the charge distribution of the system, requiring a large basis of single-electron eigenstates to be included in the model.

Cavity-photon-switched coherent transient transport in a double quantum waveguide

“…In our calculations, we include both the para-and the dia-magnetic interaction terms which lead to more complex photon-electron interaction processes than are present in the resonant two-level Jaynes-Cummings model, where only the paramagnetic term is taken into account [15]. In addition, we use exact diagonalization (configuration interaction) including many levels to treat the electron-electron Coulomb interaction and the electron-photon interaction [16][17][18] without resorting to the rotating wave approximation [19,20].…”

Symmetric excitation and de-excitation of a cavity QED system

“…To calculate for example d i |µ) we have to use d i |µ) = d i V|µ . This definition of G µν makes comparison with the JC-model easy, since the coupling energy E JC in the JC model (in the E JC σ x (a+a † ) term) is related to the DCT via E JC = |G κλ |E c where |κ) and |λ) are the two states chosen for the TLS approximation (active states) [12]. We will refer to E c as the electron-photon coupling strength (or simply the coupling strength) and E JC as the effective coupling strength.…”

“…In previous work, we have gone beyond the TLS approximation and solved the many-body Schrödinger equation exactly for electrons embedded in a semiconductor nanostructure, subject to a single mode quantized EM field and an external classical magnetic field [12]. The electron-electron and photon-electron interactions were treated exactly using exact numerical diagonalization (for details see Ref.…”

Nonperturbative approach to circuit quantum electrodynamics

“…In the ultrastrong regime, the JC model fails and evidence of the breakdown of the JC-model with the rotating wave approximation has been observed experimentally in superconducting [6] and semiconductor systems [8,9]. Exact numerical calculations predict the failure of the JC-model (even without the rotating wave approximation) where the effects of the diamagnetic matter-photon interaction term as well as effects of states which are not part of the two level system approximation come into play with high coupling strength [11].…”