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 does not depend on the temperature and that the corresponding optimized thermal entanglement decays as 1/(TlnT) 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.
|ジャーナル||Physical Review A - Atomic, Molecular, and Optical Physics|
|出版ステータス||Published - 2011 6 10|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics