Naslov
Determination of ground-state properties in quantum spin systems by single-qubit unitary operations and entanglement excitation energies

Autori
Giampaolo, S. M. ; Illuminati, F. ; Verrucchi, P. ; De Siena, S.

Izvornik
Physical review, A, Atomic, molecular, and optical physics (1050-2947) 77 (2008), 1; 012319, 6

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, ostalo

Ključne riječi
factorization

Sažetak
We introduce a method for analyzing ground-state properties of quantum many-body systems, based on the characterization of separability and entanglement by single subsystem unitary operations. We apply the method to the study of the ground-state structure of several interacting spin-1/2 models, described by Hamiltonians with different degrees of symmetry. We show that the approach based on single-qubit unitary operations allows us to introduce “entanglement excitation energies, ” a set of observables that can characterize ground- state properties, including the quantification of single- site entanglement and the determination of quantum critical points. The formalism allows us to identify the existence and location of factorization points, and a purely quantum “transition of entanglement” that occurs at the approach of factorization. This kind of quantum transition is characterized by a diverging ratio of excitation energies associated with single-qubit unitary operation.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA