https://doi.org/10.1140/epjd/e2004-00194-y
Thermal entanglement in two qutrits system
1
State Key Laboratory for Superlattices and Microstructures,
Institute of Semiconductors, Chinese Academy of Sciences,
P.O. Box 912, Beijing 100083, P.R. China
2
Institute of Theoretical Physics, Shanxi University, Taiyuan 030006, P.R. China
3
Shenfu Dongsheng Coal Limited Company Shenhua Group, Halagou Coal Mine
Daliuta Shenmu, Shanxi 719315, P.R. China
4
State Key Laboratory of Magnetism, Institute of Physics and Center for
Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, P.R. China
Corresponding author: a gf1978zhang2001@yahoo.com
Received:
9
June
2004
Revised:
21
September
2004
Published online:
4
January
2005
The thermal entanglement in a two-qutrit system with two spins coupled by exchange interaction is investigated in terms of the measure of entanglement called “negativity”. It is found that the thermal entanglement is present and evolvements symmetrically between both ferromagnetic and antiferromagnetic exchange couplings with the temperature. Moreover the critical temperature at which the negativity vanishes increases with the exchange coupling constant J. From the temperature and magnetic field dependences we demonstrate that the temperature and the magnetic field can affect the feature of the thermal entanglement significantly.
PACS: 03.65.Ud – Entanglement and quantum nonlocality (e.g. EPR paradox, Bell's inequalities, GHZ states, etc.) / 75.10.Jm – Quantized spin models / 05.50.+q – Lattice theory and statistics (Ising, Potts, etc.) / 03.67.Lx – Quantum computation
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005
