THERMAL EFFECT IN LIPKIN MODEL .1. THERMAL-EQUILIBRIUM STATE AND PHASE-TRANSITION

Authors
KURIYAMA A DAPROVIDENCIA J TSUE Y YAMAMURA M
Citation
A. Kuriyama et al., THERMAL EFFECT IN LIPKIN MODEL .1. THERMAL-EQUILIBRIUM STATE AND PHASE-TRANSITION, Progress of theoretical physics, 94(6), 1995, pp. 1039-1059
Citations number
6
Categorie Soggetti
Physics
Journal title
Progress of theoretical physics → ACNP
ISSN journal
0033068X
Volume
94
Issue
6
Year of publication
1995
Pages
1039 - 1059
Database
ISI
SICI code
0033-068X(1995)94:6<1039:TEILM.>2.0.ZU;2-L
Abstract
We study the thermal effect with the use of Lipkin model. We define th e density and entropy operator associated with the mixed state represe ntation of Lipkin model, which has been developed with the aid of auxi liary fermion field. We investigate the thermal equilibrium state and its phase transition. In super phase, the thermal effect breaks the pa rticle-hole pairs with coupled angular momentum 0 and does not lift up nucleons from the lower level to upper one, contrary to the case of n ormal phase.