Dynamics of a mesoscopic qubit ensemble coupled to a cavity: Role of collective dark states

作者:Zhukov A A; Shapiro D S; Pogosov W V; Lozovik Yu E
来源:PHYSICAL REVIEW A, 2017, 96(3): 033804.
DOI:10.1103/PhysRevA.96.033804

摘要

We consider the dynamics of a disordered ensemble of qubits interacting with a single-mode photon field, which is described by an exactly solvable inhomogeneous Dicke model. In particular, we concentrate on the crossover from few-qubit systems to the system of many qubits and analyze how the collective behavior of a coupled qubit-cavity system emerges despite the broadening. We show that quantum interference effects survive in the mesoscopic regime-the dynamics of an entangled Bell state encoded into the qubit subsystem remains highly sensitive to the symmetry of the total wave function. Moreover, relaxation of these states is slowed down due to the formation of collective dark states weakly coupled to light. Dark states also significantly influence the dynamics of the excitations of a photon subsystem by absorbing them into the qubit subsystem and releasing quasiperiodically in time. We argue that the predicted phenomena can be useful in quantum technologies based on superconducting qubits. For instance, they provide tools to deeply probe both collective and quantum properties of such artificial macroscopic systems.

  • 出版日期2017-9-5