Landau-Zener-Stückelberg-Majorana lasing in circuit quantum electrodynamics

Abstract

We demonstrate amplification (and attenuation) of a probe signal by a driven two-level quantum system in the Landau-Zener-Stückelberg-Majorana regime by means of an experiment, in which a superconducting qubit was strongly coupled to a microwave cavity, in a conventional arrangement of circuit quantum electrodynamics. Two different types of flux qubit, specifically a conventional Josephson junctions qubit and a phase-slip qubit, show similar results, namely, lasing at the working points where amplification takes place. The experimental data are explained by the interaction of the probe signal with Rabi-like oscillations. The latter are created by constructive interference of Landau-Zener-Stückelberg-Majorana (LZSM) transitions during the driving period of the qubit. A detailed description of the occurrence of these oscillations and a comparison of obtained data with both analytic and numerical calculations are given.

Double Quantum Dot Floquet Gain Medium

“…Periodic driving of the level detuning results in an effective population inversion that depends sensitively on the drive parameters and band alignment. An intricate photon emission pattern emerges as a result of cavity coupling, periodic driving, and strong electron-phonon coupling [21]. Our results can be understood in analogy to lasing without inversion in atomic physics [14].…”

Amplitude tuning of steady-state entanglement in strongly driven coupled qubits

“…For non resonant and large amplitude periodic drivings, a mechanism relying on the amplitude-modulation of the periodic (ac) signal was recently proposed for generating dissipative steady-state entanglement in a solidstate qubits system interacting with a thermal bath [15]. In analogy to well known protocols used to study Landau-Zener-Stückelberg (LZS) interferometry, multiphoton resonances [16][17][18][19][20][21][22][23][24][25] and bath-mediated population inversion [26][27][28][29] in two-level systems, entanglement in the steady state has been induced and tuned by changing the amplitude of the ac field in a system composed of two driven and coupled superconducting qubits. Interestingly, and depending on the relevant time scales, three different scenarios for entanglement evolution have been found in Ref.…”

“…However, for large amplitude periodic drivings, interesting non perturbative effects are known to exist. Among these, coherent destruction of tunneling [16][17][18], Landau-Zener-Stückelberg (LZS) interferometry [19][20][21][22][23][24][25][26][27][28] and bathmediated population inversion [11,[29][30][31] have been studied in two-level systems.Relying on these later effects, we present a new mechanism to induce steady state entanglement. Using as a test system two coupled qubits, we will demonstrate that the entanglement in the steady state can be induced and tuned by changing the amplitude of a driving periodic field.…”

Landau-Zener transitions in a fermionic dissipative environment

“…As one of the most fundamental phenomena in quantum physics, the LZ transition plays an important role in various fields such as quantum chemistry [9], atomic and molecular physics [10][11][12], solid state artificial atoms [13,14], spin flips in nanomagnets [15,16], quantum optics [17,18], Bose-Einstein condensates [19][20][21], quantum information and computation [22][23][24][25][26][27], and Landau-Zener-Stückelberg interferometry [28][29][30][31][32][33].…”