Anharmonic oscillation effect on the Davydov-Scott monomer in a thermal bath

Abstract

The dynamics of Davydov-Scott monomer in a thermal bath with higher order amide-site's displacement leads to anharmonic oscillation effect is investigated using full-quantum approach and the Lindblad formulation of master equation. The specific heat is calculated based on the thermodynamic partition function using the path integral method. The temperature dependence of the specific heat is studied. In the model the specific heat anomaly as pointed out in recent works by Ingold et.al. is also observed. However it is found that the anomaly occurs at high temperature region, and the anharmonic oscillation restores the positivity of specific heat.

Disentangling geometric and dissipative origins of negative Casimir entropies

“…As a consequence and in contrast to common expectations, decreasing the damping constant γ will render the free particle more classical and shift the transition * stefan.umrath@physik.uni-augsburg.de † gert.ingold@physik.uni-augsburg.de to the quantum behavior to lower temperatures. A negative specific heat in the sense just discussed is also found in certain systems in condensed-matter physics and related fields [6][7][8][9][10].…”

“…An increase in the dc conductivity will reduce the Rayleigh regime and render the dipole regime valid at even smaller frequencies. To ensure the validity of the Rayleigh limit, one thus has to choose either bad conductors or go to large distances satisfying (10). In the large-distance limit considered in Refs.…”

Anomalies in the specific heat of a free damped particle: the role of the cutoff in the spectral density of the coupling

“…Occasionally, we omit the subscript when the context permits it. The frequency integral (7) with (11) is convergent for s in the range 0 < s < 2p + 2 (12) and can be expressed in terms of hypergeometric functions. The resulting expression with a convergent hypergeometric series in the regime |z| > 1 iŝ…”

“…(11). For the spectral density (24), the frequency integral in the expression (7) for the spectral damping function γ(z) can again be expressed in terms of hypergeometric functions. In the frequency regime |z| > 1 one findŝ…”

“…For s < 2, substitution of the expression (9) for J 0 (ω) in (7) results in the first term appearing in the series expressions (19) and (29). With the residual contribution of J(ω), the integral expression (7) is regular in linear order of z and yields µz in this order. Importantly, the mass contribution µ emerges For the algebraic cutoff with p = 1 one finds γ ac (1, 1) = ωc, while for the sharp cutoff γ sc (1) = (π/2)ωc.…”