title: Canonical formulation of quantum dissipation and noise in a generalized spin bath.
abstract: The quantum dynamics of a particle coupled to the dissipative degrees of freedom of a generalized spin bath in the presence of an external force field is presented. Based on Holstein-Primakoff transformation, which sets up a mapping between boson and spin operators, we show that the spin-1/2 bath and the harmonic bath can be realized as two special limits of the generalized bath. In the large spin limit, the Hamiltonian reduces to well-known Zwanzig Hamiltonian. Making use of spin coherent states and canonical thermal distributions of the associated c numbers, we derive and explore the quantum Langevin equation and the properties of the spin and harmonic baths in the context of quantum dissipation of the system.
authors.affiliation: Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India.
authors.forename: Arnab
authors.initials: A
authors.lastname: Ghosh
authors.forename: Sudarson Sekhar
authors.initials: SS
authors.lastname: Sinha
authors.forename: Deb Shankar
authors.initials: DS
authors.lastname: Ray
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D060526:Magnetic Fields; D015233:Models, Statistical; D013113:Spin Labels
chemical_list: D013113:Spin Labels