A New Boson Realization of the Two-Level Pairing Model in a Many-Fermion System and Its Classical Counterpart: -- The Role of the su(2) su(1,1)-Coherent State in the Schwinger Boson Representation for the su(2) su(2)-Algebra --

DOI10.1143/PTP.115.739zbMATH Open1106.81324arXivnucl-th/0601087OpenAlexW2036485028MaRDI QIDQ5488478

João Da Providência, Masatoshi Yamamura, Yasuhiko Tsue, Constança Providência

Publication date: 22 September 2006

Published in: Progress of Theoretical Physics (Search for Journal in Brave)

Abstract: A new method for describing the two-level pairing model in a many-fermion system is presented. Basic idea comes from the Schwinger boson representation for the su(2) cross su(2)-algebra, in which four kinds of boson operators govern the dynamics. It is well known that in the original fermion space, it is almost impossible to introduce any trial state for the variation except the BCS state in the framework of the mean field approximation. However, in the Schwinger boson representation, various trial states can be defined on the condition that the mean field approximation is useful. In these states, the mixed-mode coherent state is mainly discussed in this paper.

Full work available at URL: https://arxiv.org/abs/nucl-th/0601087

Mathematics Subject Classification ID

Nuclear physics (81V35) Finite-dimensional groups and algebras motivated by physics and their representations (81R05) Operator algebra methods applied to problems in quantum theory (81R15)