Title of article :
Entanglement entropy, decoherence, and quantum phase transitions of a dissipative two-level system Original Research Article
Author/Authors :
K. Le Hur، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2008
Pages :
33
From page :
2208
To page :
2240
Abstract :
The concept of entanglement entropy appears in multiple contexts, from black hole physics to quantum information theory, where it measures the entanglement of quantum states. We investigate the entanglement entropy in a simple model, the spin-boson model, which describes a qubit (two-level system) interacting with a collection of harmonic oscillators that models the environment responsible for decoherence and dissipation. The entanglement entropy allows to make a precise unification between entanglement of the spin with its environment, decoherence, and quantum phase transitions. We derive exact analytical results which are confirmed by Numerical Renormalization Group arguments both for an ohmic and a subohmic bosonic bath. The entanglement entropy obeys universal scalings. We make comparisons with entanglement properties in the quantum Ising model and in the Dicke model. We also emphasize the possibility of measuring this entropy using charge qubits subject to electromagnetic noise; such measurements would provide an empirical proof of the existence of entanglement entropy.
Keywords :
Dissipative two-level systems , Spin-boson models , Entanglement entropy , Decoherence , Quantum phase transitions
Journal title :
Annals of Physics
Serial Year :
2008
Journal title :
Annals of Physics
Record number :
1206107
Link To Document :
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