scholarly journals The Casimir-Polder interaction of an atom and real graphene sheet: Verification of the Nernst heat theorem

2020 ◽  
Vol 35 (03) ◽  
pp. 2040004 ◽  
Author(s):  
G. L. Klimchitskaya
Keyword(s):  
Free Energy ◽  
Low Temperature ◽  
Graphene Sheet ◽  
Power Law ◽  
Chemical Potential ◽  
Energy Gap ◽  
Charge Carriers ◽  
Temperature Behavior ◽  
Polarization Tensor ◽  
Free Charge

We find the low-temperature behavior of the Casimir-Polder free energy and entropy for an atom interacting with real graphene sheet possessing nonzero energy gap and chemical potential. Employing the formalism of the polarization tensor, it is shown that the Casimir-Polder entropy goes to zero by the power law with vanishing temperature, i.e., the Nernst heat theorem is satisfied. This result is discussed in connection with the problems connected with account of free charge carriers in the Lifshitz theory.

Chemical potential, Gibbs–Duhem equation and quantum gases

2017 ◽  
Vol 31 (13) ◽  
pp. 1750104
Author(s):  
M. Howard Lee
Keyword(s):  
Low Temperature ◽  
Thermodynamic Functions ◽  
Chemical Potential ◽  
Quantum Gases ◽  
Temperature Behavior ◽  
Bose Gases ◽  
Duhem Equation ◽  
Temperature Form ◽  
Specific Temperature ◽  
The Ideal

Thermodynamic relations like the Gibbs–Duhem are valid from the lowest to the highest temperatures. But they cannot by themselves provide any specific temperature behavior of thermodynamic functions like the chemical potential. In this work, we show that if some general conditions are attached to the Gibbs–Duhem equation, it is possible to obtain the low temperature form of the chemical potential for the ideal Fermi and Bose gases very directly.

scholarly journals Raman Scattering in Cuprate Superconductors

1997 ◽  
Vol 11 (18) ◽  
pp. 2093-2118 ◽  
Author(s):  
Thomas Peter Devereaux ◽  
Arno Paul Kampf
Keyword(s):  
Low Temperature ◽  
Raman Scattering ◽  
Raman Spectra ◽  
Cuprate Superconductors ◽  
Energy Gap ◽  
Low Frequency ◽  
Temperature Behavior ◽  
Doping Dependence ◽  
Electronic Raman Scattering ◽  
Effects Of Disorder

A theory for electronic Raman scattering in the cuprate superconductors is presented with a specific emphasis on the polarization dependence of the spectra which can infer the symmetry of the energy gap. Signatures of the effects of disorder on the low frequency and low temperature behavior of the Raman spectra for different symmetry channels provide detailed information about the magnitude and the phase of the energy gap. Properties of the theory for finite T will be discussed and compared to recent data concerning the doping dependence of the Raman spectra in cuprate superconductors, and remaining questions will be addressed.

scholarly journals Casimir and Casimir-Polder Forces in Graphene Systems: Quantum Field Theoretical Description and Thermodynamics

Universe ◽  
2020 ◽  
Vol 6 (9) ◽  
pp. 150
Author(s):  
Galina L. Klimchitskaya ◽  
Vladimir M. Mostepanenko
Keyword(s):  
Free Energy ◽  
Low Temperature ◽  
Theoretical Description ◽  
Electromagnetic Response ◽  
Graphene Sheets ◽  
Pristine Graphene ◽  
Polarization Tensor ◽  
Quantum Field ◽  
New Findings ◽  
Lifshitz Theory

We review recent results on the low-temperature behaviors of the Casimir-Polder and Casimir free energy an entropy for a polarizable atom interacting with a graphene sheet and for two graphene sheets, respectively. These results are discussed in the wide context of problems arising in the Lifshitz theory of van der Waals and Casimir forces when it is applied to metallic and dielectric bodies. After a brief treatment of different approaches to theoretical description of the electromagnetic response of graphene, we concentrate on the derivation of response function in the framework of thermal quantum field theory in the Matsubara formulation using the polarization tensor in (2 + 1)-dimensional space—time. The asymptotic expressions for the Casimir-Polder and Casimir free energy and entropy at low temperature, obtained with the polarization tensor, are presented for a pristine graphene as well as for graphene sheets possessing some nonzero energy gap Δ and chemical potential μ under different relationships between the values of Δ and μ. Along with reviewing the results obtained in the literature, we present some new findings concerning the case μ≠0, Δ=0. The conclusion is made that the Lifshitz theory of the Casimir and Casimir-Polder forces in graphene systems using the quantum field theoretical description of a pristine graphene, as well as real graphene sheets with Δ>2μ or Δ<2μ, is consistent with the requirements of thermodynamics. The case of graphene with Δ=2μ≠0 leads to an entropic anomaly, but is argued to be physically unrealistic. The way to a resolution of thermodynamic problems in the Lifshitz theory based on the results obtained for graphene is discussed.

scholarly journals Metal-to-insulator transition in Pt-doped TiSe2 driven by emergent network of narrow transport channels

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Kyungmin Lee ◽  
Jesse Choe ◽  
Davide Iaia ◽  
Juqiang Li ◽  
Junjing Zhao ◽  
...  
Keyword(s):  
Domain Walls ◽  
Chemical Potential ◽  
Energy Gap ◽  
Local Density ◽  
Density Wave ◽  
Charge Carriers ◽  
Scanning Tunneling ◽  
Resistive State ◽  
Excess Charge ◽  
Tunneling Microscopy

AbstractMetal-to-insulator transitions (MIT) can be driven by a number of different mechanisms, each resulting in a different type of insulator—Change in chemical potential can induce a transition from a metal to a band insulator; strong correlations can drive a metal into a Mott insulator with an energy gap; an Anderson transition, on the other hand, due to disorder leads to a localized insulator without a gap in the spectrum. Here, we report the discovery of an alternative route for MIT driven by the creation of a network of narrow channels. Transport data on Pt substituted for Ti in 1T-TiSe2 shows a dramatic increase of resistivity by five orders of magnitude for few % of Pt substitution, with a power-law dependence of the temperature-dependent resistivity ρ(T). Our scanning tunneling microscopy data show that Pt induces an irregular network of nanometer-thick domain walls (DWs) of charge density wave (CDW) order, which pull charge carriers out of the bulk and into the DWs. While the CDW domains are gapped, the charges confined to the narrow DWs interact strongly, with pseudogap-like suppression in the local density of states, even when they were weakly interacting in the bulk, and scatter at the DW network interconnects thereby generating the highly resistive state. Angle-resolved photoemission spectroscopy spectra exhibit pseudogap behavior corroborating the spatial coexistence of gapped domains and narrow domain walls with excess charge carriers.

scholarly journals The Low-Temperature Expansion of the Casimir-Polder Free Energy of an Atom with Graphene

Universe ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 70
Author(s):  
Nail Khusnutdinov ◽  
Natalia Emelianova
Keyword(s):  
Free Energy ◽  
Low Temperature ◽  
Chemical Potential ◽  
Fermi Velocity ◽  
Thermal Correction ◽  
Temperature Expansion ◽  
Poisson Representation ◽  
Zero Values ◽  
Gap Parameter ◽  
Exact Equality

We consider the low-temperature expansion of the Casimir-Polder free energy for an atom and graphene by using the Poisson representation of the free energy. We extend our previous analysis on the different relations between chemical potential μ and mass gap parameter m. The key role plays the dependence of graphene conductivities on the μ and m. For simplicity, we made the manifest calculations for zero values of the Fermi velocity. For μ>m, the thermal correction ∼T2, and for μ<m, we confirm the recent result of Klimchitskaya and Mostepanenko, that the thermal correction ∼T5. In the case of exact equality μ=m, the correction ∼T. This point is unstable, and the system falls to the regime with μ>m or μ<m. The analytical calculations are illustrated by numerical evaluations for the Hydrogen atom/graphene system.

scholarly journals Nernst heat theorem for the Casimir-Polder interaction between a magnetizable atom and ferromagnetic dielectric plate

2020 ◽  
Vol 35 (03) ◽  
pp. 2040010 ◽  
Author(s):  
C. C. Korikov ◽  
V. M. Mostepanenko
Keyword(s):  
Free Energy ◽  
Low Temperature ◽  
Dielectric Material ◽  
Dc Conductivity ◽  
Temperature Behavior ◽  
Plate Material ◽  
Dielectric Plate ◽  
Nernst Theorem

We find the low-temperature behavior of the Casimir-Polder free energy for a polarizable and magnetizable atom interacting with a plate made of ferromagnetic dielectric material. It is shown that the corresponding Casimir-Polder entropy goes to zero with vanishing temperature, i.e., the Nernst heat theorem is satisfied, if the dc conductivity of the plate material is disregarded in calculations. If the dc conductivity is taken into account, the Nernst theorem is violated. These results are discussed in light of recent experiments.

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