Entangled-state cycles from conditional quantum evolution

Abstract

A system of cascaded qubits interacting via the oneway exchange of photons is studied. While for general operating conditions the system evolves to a superposition of Bell states (a dark state) in the long-time limit, under a particular resonance condition no steady state is reached within a finite time. We analyze the conditional quantum evolution (quantum trajectories) to characterize the asymptotic behavior under this resonance condition. A distinct bimodality is observed: for perfect qubit coupling, the system either evolves to a maximally entangled Bell state without emitting photons (the dark state), or executes a sustained entangled-state cycle - random switching between a pair of Bell states while emitting a continuous photon stream; for imperfect coupling, two entangled-state cycles coexist, between which a random selection is made from one quantum trajectory to another.

12 pages, 10 figures

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Cited by in corpus (7)

• Driven-dissipative preparation of entangled states in cascaded quantum-optical networks
• Multi-parameter estimation beyond Quantum Fisher Information
• Enhancement of quantum synchronization via continuous measurement and feedback control
• Entanglement evolution in a cascaded system with losses
• Entangled-State Cycles of Atomic Collective-Spin States
• Entanglement in a Raman-driven cascaded system
• Quantum walks and entanglement in cavity networks