2011/04/04 by Tomotaka Kuwahara, Naomichi Hatano
Computer Science · Mathematics · Physics and Astronomy · #Hamiltonian (control theory) #Mathematical optimization #Mathematics #Maximization #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum entanglement #Quantum mechanics #Qubit #Squashed entanglement #Thermal #Thermodynamics #cond-mat.mes-hall #math-ph #math.MP #quant-ph
paper · pdf · doi:10.1103/physreva.83.062311
published as Phys. Rev. A 83, 062311 (2011) · 23 pages, 4 figures
arxiv created 2011/04/04 · openalex publication_date 2011/06/10 · arxiv updated 2012/07/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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.