Thermo Field Boson Realizations for Operators of the Finite Temperature Random Phase Approximation

摘要

An essentially new Dyson realization for two-quasiparticle operators at finite temperature is derived by using the Thermo Field Dynamic formalism. The operators of the Finite Temperature Random Phase Approximation (FT-RPA) are constructed from the zero temperature two-quasiparticle operators. The conditions are found under which these thermal RPA quadrupole operators close the SU(6) algebra. The Dyson, Holstein-Primakoff and Schwinger boson realizations for the thermal RPA operators in the case of SU(6) symmetry are obtained. The relation with the schematic two-level model thermal boson expansion is pointed out. 14 refs. (Atomindex citation 20:020867)