Thermalization through unitary evolution of pure statesS. O. Skrovseth
Department of Physics, Norwegian University of Science and Technology N-7491 Trondheim, Norway
received 26 June 2006; accepted in final form 20 October 2006
published online 23 November 2006
The unitary time evolution of a critical quantum spin chain with an impurity is calculated, and the entanglement evolution is shown. Moreover, we show that the reduced density matrix of a part of the chain evolves such that the fidelity of its spectrum is very high with respect to a state in thermal equilibrium. Hence, a thermal state occurs through unitary time evolution in a simple spin chain with impurity.
75.10.Pq - Spin chain models.
03.65.Ud - Entanglement and quantum nonlocality (e.g. EPR paradox, Bell's inequalities, GHZ states, etc.).
65.90.+i - Other topics in thermal properties of condensed matter.
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