scholarly journals A Dirac-Fermions functional for Coulomb interaction on arbitrary (fractional) dimension: Energy and pressure

2021 ◽  
pp. 127363
Author(s):  
J.C. Flores
Keyword(s):  
Coulomb Interaction ◽  
Fractional Dimension ◽  
Dirac Fermions

MAGNETIC SUSCEPTIBILITY OF GRAPHENE BY GAUSSIAN CORRECTION

2011 ◽  
Vol 25 (15) ◽  
pp. 1981-1991 ◽  
Author(s):  
PEISONG HE
Keyword(s):  
Magnetic Susceptibility ◽  
Coulomb Interaction ◽  
Fermi Liquid ◽  
Collective Excitations ◽  
Dirac Fermions ◽  
Coulomb Interactions ◽  
Linear Dispersion ◽  
Fermi Liquid Theory ◽  
Liquid Theory ◽  
Spatial Dimensions

In the present paper, we compute the magnetic susceptibility of graphene by using Gaussian correction. The collective excitations away from Fermi points of graphene are gapless, chiral fermions, with linear dispersion. The system is modeled as N massless Dirac fermions in two spatial dimensions interacting with 1/r Coulomb interactions. We find that the magnetic susceptibility is suppressed by the interaction between these collective excitations. And it has ln T correction due to the long-ranged Coulomb interaction, which is different from Landau Fermi liquid theory.

Coulomb interaction of composite particles

1983 ◽  
Vol 141 (11) ◽  
pp. 552
Author(s):  
D.A. Kirzhnits ◽  
F.M. Pen'kov
Keyword(s):  
Coulomb Interaction ◽  
Composite Particles

Excitonic quasimolecules containing of two quantum dots

2016 ◽  
pp. 4024-4028 ◽  
Author(s):  
Sergey I. Pokutnyi ◽  
Wlodzimierz Salejda
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Exchange Interaction ◽  
Coulomb Interaction ◽  
Silicate Glass ◽  
Glass Matrix ◽  
Silicate Glass Matrix

The possibility of occurrence of the excitonic  quasimolecule formed of spatially separated electrons and holes in a nanosystem that consists  of  CuO quantum dots synthesized in a silicate glass matrix. It is shown that the major contribution to the excitonic quasimolecule binding energy is made by the energy of the exchange interaction of electrons with holes and this contribution is much more substantial than the contribution of the energy of Coulomb interaction between the electrons and holes.

Screened Coulomb interaction or Hubbard model?

1991 ◽  
Vol 177 (1-3) ◽  
pp. 578-584 ◽  
Author(s):  
Daniel C. Mattis ◽  
Douglas Henderson
Keyword(s):  
Hubbard Model ◽  
Coulomb Interaction

scholarly journals The influence of Coulomb interaction screening on the excitons in disordered two-dimensional insulators

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
E. V. Kirichenko ◽  
V. A. Stephanovich
Keyword(s):  
Coulomb Interaction ◽  
Energy Levels ◽  
Transition Metal Dichalcogenides ◽  
Extreme Case ◽  
Bound State ◽  
Joint Effect ◽  
Two Dimensional ◽  
Inorganic Substances ◽  
Metal Dichalcogenides ◽  
Interaction Screening

AbstractWe study the joint effect of disorder and Coulomb interaction screening on the exciton spectra in two-dimensional (2D) structures. These can be van der Waals structures or heterostructures of organic (polymeric) semiconductors as well as inorganic substances like transition metal dichalcogenides. We consider 2D screened hydrogenic problem with Rytova–Keldysh interaction by means of so-called fractional Scrödinger equation. Our main finding is that above synergy between screening and disorder either destroys the exciton (strong screening) or promote the creation of a bound state, leading to its collapse in the extreme case. Our second finding is energy levels crossing, i.e. the degeneracy (with respect to index $$\mu $$ μ ) of the exciton eigenenergies at certain discrete value of screening radius. Latter effects may also be related to the quantum manifestations of chaotic exciton behavior in above 2D semiconductor structures. Hence, they should be considered in device applications, where the interplay between dielectric screening and disorder is important.

scholarly journals Xenon-1T excess as a possible signal of a sub-GeV hidden sector dark matter

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Amin Aboubrahim ◽  
Michael Klasen ◽  
Pran Nath
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Small Mass ◽  
Big Bang ◽  
Mass Splitting ◽  
Recoil Energy ◽  
Dirac Fermions ◽  
Dark Sector ◽  
Dark Photon ◽  
Physics Model

Abstract We present a particle physics model to explain the observed enhancement in the Xenon-1T data at an electron recoil energy of 2.5 keV. The model is based on a U(1) extension of the Standard Model where the dark sector consists of two essentially mass degenerate Dirac fermions in the sub-GeV region with a small mass splitting interacting with a dark photon. The dark photon is unstable and decays before the big bang nucleosynthesis, which leads to the dark matter constituted of two essentially mass degenerate Dirac fermions. The Xenon-1T excess is computed via the inelastic exothermic scattering of the heavier dark fermion from a bound electron in xenon to the lighter dark fermion producing the observed excess events in the recoil electron energy. The model can be tested with further data from Xenon-1T and in future experiments such as SuperCDMS.

scholarly journals Deformation of the Fermi surface of a spinless two-dimensional electron gas in presence of an anisotropic Coulomb interaction potential

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Orion Ciftja
Keyword(s):  
Fermi Surface ◽  
Coulomb Interaction ◽  
Interaction Potential ◽  
Fermi Liquid ◽  
Energy State ◽  
Electron Gas ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Two Dimensional Electron Gas ◽  
Dimensional Electron Gas

AbstractWe consider the stability of the circular Fermi surface of a two-dimensional electron gas system against an elliptical deformation induced by an anisotropic Coulomb interaction potential. We use the jellium approximation for the neutralizing background and treat the electrons as fully spin-polarized (spinless) particles with a constant isotropic (effective) mass. The anisotropic Coulomb interaction potential considered in this work is inspired from studies of two-dimensional electron gas systems in the quantum Hall regime. We use a Hartree–Fock procedure to obtain analytical results for two special Fermi liquid quantum electronic phases. The first one corresponds to a system with circular Fermi surface while the second one corresponds to a liquid anisotropic phase with a specific elliptical deformation of the Fermi surface that gives rise to the lowest possible potential energy of the system. The results obtained suggest that, for the most general situations, neither of these two Fermi liquid phases represent the lowest energy state of the system within the framework of the family of states considered in this work. The lowest energy phase is one with an optimal elliptical deformation whose specific value is determined by a complex interplay of many factors including the density of the system.

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