1997/11/30 by Takeo Kato, Masatoshi Imada
Engineering · Materials Science · Physics and Astronomy · #Quantum and electron transport phenomena #Thermal properties of materials #Thermoelastic and Magnetoelastic Phenomena #cond-mat.mes-hall #cond-mat.stat-mech
paper · pdf · doi:10.1143/jpsj.67.2828
30 pages, 11 figs, to be published on J. Phys. Soc. Jpn., improved version by adding one new figure and removing some mistakes
arxiv created 1998/05/18 · openalex publication_date 1998/08/15 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Thermodynamics and transport properties of a dissipative particle in a tight-binding model are studied through specific heat and optical conductivity. A weak coupling theory is constituted to study the crossover behavior between the low-temperature region and the high-temperature region analytically. We found that coherent part around zero frequency in the optical conductivity disappears for 0<s<2, where s is an exponent of a spectral function of the environment. Detailed calculation is performed for ohmic damping (s=1). In this case, the specific heat shows an unusual T-linear behavior at low temperatures, which indicates that the environment strongly influences the particle motion, and changes the low-energy states of the dissipative particle. The optical conductivity σ(ω) takes a non-Drude form even at zero temperature, and the high-frequency side behaves as ω^(2K-2), where K is a dimensionless damping strength. The high frequency side of the optical conductivity is independent of temperatures, while the low frequency side depends on the temperature, and behaves as T^(2K-2) at high temperatures. We also comment on the application of this model to the description of incoherent motion in correlated electron systems.