Maximization of thermal entanglement of arbitrarily interacting two qubits

Abstract

We investigate the thermal entanglement of interacting two qubits. We maximize it by tuning a local Hamiltonian under a given interaction Hamiltonian. We prove that the optimizing local Hamiltonian takes a simple form which dose not depend on the temperature and that the corresponding optimized thermal entanglement decays as $1/(TlogT)$ at high temperatures. We also find that at low temperatures the thermal entanglement is maximum without any local Hamiltonians and that the second derivative of the maximized thermal entanglement changes discontinuously at the boundary between the high- and low-temperature phases.

23 pages, 4 figures

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• Quantum entanglement
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• Thermal entanglement in a two-qubit Heisenberg XXZ spin chain under an inhomogeneous magnetic field
• The effect of spin-orbit interaction on entanglement of two-qubit Heisenberg XYZ systems in an inhomogeneous magnetic field
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Cited by in corpus (4)

• Exponential clustering of bipartite quantum entanglement at arbitrary temperatures
• General conditions for the generation of long-distance entanglement
• Quantum thermalization and thermal entanglement in the open quantum Rabi model
• Role of external fields in enhancing long-distance entanglement at finite temperatures