Topic
Debye frequency
About: Debye frequency is a research topic. Over the lifetime, 251 publications have been published within this topic receiving 4090 citations.
Papers published on a yearly basis
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Papers
TL;DR: It is argued that the intrinsic glassy degrees of freedom in amorphous solids giving Rise to the thermal conductivity plateau and the “boson peak” in the heat capacity at moderately low temperatures are directly connected to those motions giving rise to the two-level-like excitations seen at still lower temperatures.
Abstract: We argue that the intrinsic glassy degrees of freedom in amorphous solids giving rise to the thermal conductivity plateau and the “boson peak” in the heat capacity at moderately low temperatures are directly connected to those motions giving rise to the two-level-like excitations seen at still lower temperatures. These degrees of freedom can be thought of as strongly anharmonic transitions between the local minima of the glassy energy landscape that are accompanied by ripplon-like domain wall motions of the glassy mosaic structure predicted to occur at Tg by the random first-order transition theory. The energy spectrum of the vibrations of the mosaic depends on the glass transition temperature, the Debye frequency, and the molecular length scale. The resulting spectrum reproduces the experimental low-temperature boson peak. The “nonuniversality” of the thermal conductivity plateau depends on kBTg/ℏωD and arises from calculable interactions with the phonons.
187 citations
TL;DR: It is found that contrary to some previous expectations, triplet correlations, odd in time, are induced in both the S and F layers in the clean limit, and the triplet amplitudes are largest at times on the order of the inverse Debye frequency.
Abstract: We study triplet pairing correlations in clean ferromagnet ($F$)/superconductor ($S$) nanojunctions, via fully self-consistent solution of the Bogoliubov--de Gennes equations. We consider FSF trilayers, with $S$ being an $s$-wave superconductor, and an arbitrary angle $\ensuremath{\alpha}$ between the magnetizations of the two $F$ layers. We find that contrary to some previous expectations, triplet correlations, odd in time, are induced in both the $S$ and $F$ layers in the clean limit. We investigate their behavior as a function of time, position, and $\ensuremath{\alpha}$. The triplet amplitudes are largest at times on the order of the inverse Debye frequency, and at that time scale they are long-ranged in both $S$ and $F$. The zero temperature condensation energy is found to be lowest when the magnetizations are antiparallel.
132 citations
1 Nov 1963
TL;DR: In this article, a mechanism is proposed to account for the second dispersion region which occurs in polar liquids at frequencies higher than the Debye frequency, which is a vibration of the molecules about temporary equilibrium positions which are determined by the arrangement of the neighbours.
Abstract: A mechanism is proposed to account for the second dispersion region which occurs in polar liquids at frequencies higher than the Debye frequency. This mechanism is a vibration of the molecules about temporary equilibrium positions which are determined by the arrangement of the neighbours. It leads to a value of the high frequency limit, ∞, of the Cole-Cole arc for the Debye dispersion given by (∞ - n2)/(0 - n2) = 2kT/Iω02, where ω0 is the resonant frequency of the vibration, n is the optical refractive index and I is the mean moment of inertia of the molecules about axes normal to the dipole axis, but provided ω0 >> 1/τ, where τ is the dielectric relaxation time, it does not modify the semicircular form of the arc.
119 citations
TL;DR: In this paper, the authors used non-equilibrium molecular dynamics simulations to characterize the ductile tensile failure of a model body-centered cubic metal, tantalum, over six orders of magnitude in strain rate.
115 citations
TL;DR: The ZA phonons have the dominant contribution to the thermal conductivity, and the relative contribution is almost 80% at room temperature, which is remarkably higher than that for monolayer MoS2.
Abstract: By using first-principles calculations combined with the phonon Boltzmann transport equation, we systematically investigate the phonon transport of monolayer WSe2. Compared with other 2D materials, the monolayer WSe2 is found to have an ultralow thermal conductivity due to the ultralow Debye frequency and heavy atom mass. The room temperature thermal conductivity for a typical sample size of 1 μm is 3.935 W/m K, which is one order of magnitude lower than that of MoS2. And the room temperature thermal conductivity can be further decreased by about 95% in 10 nm sized samples. Moreover, we also find the ZA phonons have the dominant contribution to the thermal conductivity, and the relative contribution is almost 80% at room temperature, which is remarkably higher than that for monolayer MoS2. This is because the ZA phonons have longer lifetime than that of LA and TA phonons in monolayer WSe2.
106 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 10 |
| 2020 | 12 |
| 2019 | 6 |
| 2018 | 3 |
| 2017 | 5 |
| 2016 | 8 |