Two-frequency Jahn-Teller systems in circuit QED

Abstract

We investigate the simulation of Jahn-Teller models with two nondegenerate vibrational modes using a circuit QED architecture. Typical Jahn-Teller systems are anisotropic and require at least a two-frequency description. The proposed simulator consists of two superconducting lumped-element resonators interacting with a common flux qubit in the ultrastrong coupling regime. We translate the circuit QED model of the system to a two-frequency Jahn-Teller Hamiltonian and calculate its energy eigenvalues and the emission spectrum of the cavities. It is shown that the system can be systematically tuned to an effective single-mode Hamiltonian from the two-mode model by varying the coupling strength between the resonators. The flexibility in manipulating the parameters of the circuit QED simulator permits the isolation of the effective single-frequency and pure two-frequency effects in the spectral response of Jahn-Teller systems.

Collective Modes in the Cooperative Jahn–Teller Model: Path Integral Approach

“…, N) which impliesᾱ γ,k = 0. Assuming sin(θ j ) = 0, the conditionφ j =φ l =φ solved the second equation in (14). The latter is the arbitrary choice for a direction of spontaneous symmetry breaking where the system chooses a direction along which to order.…”

“…Here the bosons represent a single or several quantized modes inside of an electromagnetic resonators, while the spin degrees of freedom are implemented either by real two-level atom, or artificial atoms such as quantum dot or superconducting circuit. Recently it was shown that the interaction between the quantum dot [13] or superconducting circuit [14] with two cavity modes leads to the Jahn-Teller coupling. Arranging atoms and resonators in the form of lattice can realize our model (1), with coupling between the resonators provided by the photon hopping.…”

“…Furthermore, the collective effects induced by the Jahn-Teller coupling may explain the transition of some solids, such as fullerene compounds, to high-temperature superconductors [10]. With the current quantum optical technologies the cJT model can be realized in laser or magnetically driven ion crystal [11,12] and cavity/circuit QED systems based on superconducting qubits in transmission line resonators [13,14]. Here we focus on E ⊗ e Jahn-Teller model which possess continuous U(1) symmetry.…”

On-chip photonic transistor based on the spike synchronization in circuit QED

“…The capacitive coupling between resonators is mediated by C c . A 3-phase Josephson junction flux qubit is used as an artificial superconducting atom simultaneously coupled to each resonator through coupling inductances L c1,c2 of individual inductors [8,19,47]. The coupling strength between resonators is tuned by hopping parameter J = C c ω1ω2 4C1C1…”

“…In terms of two superconducting LC resonators coupled with a common two-level artificial atom is used as a simulator in the ultrastrong coupling regime [19]. Two-frequency JT system can be switched to an effective single mode from the two-mode model by tuning the hopping term between the resonator in different coupling regimes [20,21].…”