Limit temperature for entanglement in generalized statistics

R. ROSSIGNOLI; N. CANOSA

PHYSICS LETTERS A

Elsevier

Lugar: Amsterdam; Año: 2004 vol. 323 p. 22 - 28

0375-9601

We discuss the main properties of general thermal states derived from non-additive  entropic forms and their use for studying quantum entanglement. It is shown that  all these states become more mixed as the temperature increases, approaching the   full random state for T -> infinity. The formalism is then applied  to examine  the limit temperature for entanglement in a two-qubit XXZ Heisenberg chain. which  exhibits the peculiar feature of being independent of the applied magnetic field in  the conventional von Neumann based statistics. In contrast, this temperature is   shown to be field dependent in a generalized statistics, even for small deviations  from  the standard form. Results for the Tsallis-based statistics are examined in  detail.