Natural thermal and magnetic entanglement in the 1D Heisenberg model - art. no. 017901

We investigate the entanglement between any two spins in a one dimensional Heisenberg chain as a function of temperature and the external magnetic fie ld. We find that the entanglement in an antiferromagnetic chain can be incr eased by increasing the temperature or the external field. Increasing the f ield can also create entanglement between otherwise disentangled spins. Thi s entanglement can be confirmed by testing Bell's inequalities involving an y two spins in the solid.