TY - JOUR
T1 - Thermodynamics and Optical Conductivity of a Dissipative Carrier in a Tight Binding Model
AU - Kato, Takeo
AU - Imada, Masatoshi
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1998/8
Y1 - 1998/8
N2 - 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 ω2K-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 T2K-2 at high temperatures. We also comment on the application of this model to the description, of incoherent motion in correlated electron systems.
AB - 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 ω2K-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 T2K-2 at high temperatures. We also comment on the application of this model to the description, of incoherent motion in correlated electron systems.
KW - Coherence
KW - Dissipation
KW - Incoherence
KW - Kubo formula
KW - Ohmic damping
KW - Optical conductivity
KW - Specific heat
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U2 - 10.1143/JPSJ.67.2828
DO - 10.1143/JPSJ.67.2828
M3 - Article
AN - SCOPUS:0032354494
VL - 67
SP - 2828
EP - 2846
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 8
ER -