Sudden death, birth and stable entanglement in a two-qubit Heisenberg XY spin chain

Abstract

Taking the decoherence effect due to population relaxation into account, we investigate the entanglement properties for two qubits in the Heisenberg XY interaction and subject to an external magnetic field. It is found that the phenomenon of entanglement sudden death (ESD) as well as sudden birth(ESB) appear during the evolution process for particular initial states. The influence of the external magnetic field and the spin environment on ESD and ESB are addressed in detail. It is shown that the concurrence, a measure of entanglement, can be controlled by tuning the parameters of the spin chain, such as the anisotropic parameter, external magnetic field, and the coupling strength with their environment. In particular, we find that a critical anisotropy constant exists, above which ESB vanishes while ESD appears. It is also notable that stable entanglement, which is independent of different initial states of the qubits, occurs even in the presence of decoherence.

11 pages, 4 figures

References in corpus (9)

• Finite-Time Disentanglement via Spontaneous Emission
• Quantum Open System Theory: Bipartite Aspects
• Heralded Entanglement between Atomic Ensembles: Preparation, Decoherence, and Scaling
• Delayed (sudden) birth of entanglement
• Thermal entanglement in a two-qubit Heisenberg XXZ spin chain under an inhomogeneous magnetic field
• Transfer and teleportation of quantum states encoded in decoherence-free subspace
• Fault-Tolerant Quantum Computation via Exchange interactions
• Controllable dynamics of two separate qubits in Bell states
• The entanglement in one-dimensional random XY spin chain with Dzyaloshinskii-Moriya interaction

Cited by in corpus (1)

• Sudden death of distillability in qutrit-qutrit systems