Identifying a correlated spin fluctuation in an entangled spin chain subject to a quantum phase transition
Open Access
- 28 December 2015
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review E
- Vol. 92 (6), 062143
- https://doi.org/10.1103/physreve.92.062143
Abstract
This paper presents a theoretical framework for analyzing the quantum fluctuation properties of a quantum spin chain subject to a quantum phase transition. We can quantify the fluctuation properties by examining the correlation between the fluctuations of two neighboring spins subject to the quantum uncertainty. To do this, we first compute the reduced density matrix ρ of the spin pair from the ground state |Ψ⟩ of a spin chain, and then identify the quantum correlation part embedded in ρ. If the spin chain is translationally symmetric and characterized by a nearest-neighbor two-body spin interaction, we can determine uniquely the form of as with the weight , and quantify the fluctuation properties using the two-spin entangled state . We demonstrate the framework for a transverse-field quantum Ising spin chain and indicate its validity for more general spin chain models.
Keywords
This publication has 13 references indexed in Scilit:
- Entanglement in many-body systemsReviews of Modern Physics, 2008
- Approach to the quantum phase transition of spin chains in terms of pair-wise entanglementPhysics Letters A, 2006
- Entanglement in a simple quantum phase transitionPhysical Review A, 2002
- Scaling of entanglement close to a quantum phase transitionNature, 2002
- Separable approximation for mixed states of composite quantum systemsPhysical Review A, 2001
- Three qubits can be entangled in two inequivalent waysPhysical Review A, 2000
- Separability and Entanglement of Composite Quantum SystemsPhysical Review Letters, 1998
- Entanglement of Formation of an Arbitrary State of Two QubitsPhysical Review Letters, 1998
- Entanglement measures and purification proceduresPhysical Review A, 1998
- Separability Criterion for Density MatricesPhysical Review Letters, 1996