30 citations · 139 across the 18 of their papers we have counts for
18 papers
Influence of Dynamical Floquet Spectrum on the Plasmon Excitations and Exchange Energy of tilted monolayer 1TMoS
Sita Kandel, Godfrey Gumbs, Antonios Balassis +2
It is now well established that a high-frequency electromagnetic dressing field within the off-resonance regime significantly modifies the electronic transport and optical properti…
Polarizability, plasmons, and screening in 1T-MoS with tilted Dirac bands
Antonios Balassis, Godfrey Gumbs, Oleksiy Roslyak
In the presence of an external vertical electric field and strain, it is evident that 1T-MoS exhibits tilted Dirac bands which are valley-spin-polarized. Additionall…
Effect of magnetic field and chemical potential on the RKKY interaction in the - lattice
Oleksiy Roslyak, Godfrey Gumbs, Antonios Balassis +1
The interaction energy for the indirect-exchange or Ruderman-Kittel-Kasuva-Yosida (RKKY) interaction between magnetic spins localized on lattice sites of the - model…
Magnetoplasmons for the -T model with filled Landau levels
Antonios Balassis, Dipendra Dahal, Godfrey Gumbs +3
Using the -T model, we carried out analytical and numerical calculations for the static and dynamic polarization functions in the presence of a perpendicular magnetic field.…
Combined effect of doping and temperature on the anisotropy of low-energy plasmons in monolayer graphene
Godfrey Gumbs, Antonios Balassis, V. M. Silkin
We compare the two-dimensional (2D) plasmon dispersion relations for monolayer graphene when the sample is doped with carriers in the conduction band and the temperature is zer…
Effect of Temperature and Doping on Plasmon Excitations for an Encapsulated Double-Layer Graphene Heterostructure
Godfrey Gumbs, Dipendra Dahal, Antonios Balassis
We perform a comprehensive analysis of the spectrum of graphene plasmons which arise when a pair of sheets are confined between conducting materials. The associated enhanced local…
Thermal smearing of the magneto-Kohn anomaly for Dirac materials and comparison with the two-dimensional electron liquid
Godfrey Gumbs, Antonios Balassis, Dipendra Dahal +1
We compute and compare the effects due to a uniform perpendicular magnetic field as well as temperature on the static polarization functions for monolayer graphene (MLG), associate…
Plasmons in a Superlattice of Fullerenes or Metallic Shells
Antonios Balassis, Godfrey Gumbs
A theory for the collective plasma excitations in a linear periodic array of spherical two-dimensional electron gases (S2DEGs) is presented. This is a simple model for an ultra thi…
Influence of Dielectric Environment on Role of Spin-Orbit Interaction for Image Potentials
Godfrey Gumbs, Oleksiy Roslyak, Danhong Huang +1
We present a formalism for calculating the image potential for a two-dimensional electron gas (2DEG) with Rashba spin-orbit interaction (SOI) as well as for a 2D topological insula…
Anisotropic plasmon-coupling dimerization of a pair of spherical electron gases
Godfrey Gumbs, Andrii Iurov, Antonios Balassis +1
We have discovered a novel feature in the plasmon excitations for a pair of Coulomb-coupled non- concentric spherical two-dimensional electron gases (S2DEGs). Our results show that…
Electronic properties of closed cage nanometer-size spherical graphitic particles
Godfrey Gumbs, Antonios Balassis, Andrii Iurov +1
We investigate the localization of charged particles by the image potential of spherical shells, such as fullerene buckyballs. These "spherical image states" exist within surface p…
A half-step in quantized conductance for low-density electrons in a quantum wire
Godfrey Gumbs, Antonios Balassis, Danhong Huang +2
We investigated the effect due to perpendicular magnetic field on quantum wires where spin-orbit interaction (SOI) of electrons is not neglected. Based on the calculated energy dis…
Spectroscopic Characterization of Gapped Graphene in the Presence of Circularly Polarized Light
Godfrey Gumbs, O. Roslyak, Danhong Huang +1
We present a description of the energy loss of a charged particle moving parallel to a graphene layer and graphene double layers. Specifically, we compare the stopping power of the…
Formula for the Absorption Coefficient for Multi-Wall Nanotubes
Godfrey Gumbs, Antonios Balassis
We present a formalism for calculating the absorption coefficient of a pair of coaxial tubules. A spatially nonlocal, dynamical self-consistent field theory is obtained by calculat…
Model of plasmon excitations in a bundle and two-dimensional array of nanotubes
Tibab McNeish, Godfrey Gumbs, Antonios Balassis
We calculate the plasma excitations in a bundle as well as a two-dimensional (2D) periodic array of aligned parallel multishell nanotubes on a substrate. The carbon nanotubes are o…
Enhanced response of current-driven coupled quantum wells
Antonios Balassis, Godfrey Gumbs
We have investigated the conditions necessary to achieve stronger Cherenkov-like instability of plasma waves leading to emission in the terahertz (THz) regime for semiconductor qua…
Energy bands, conductance and thermoelectric power for ballistic electrons in a nanowire with spin-orbit interaction
Godfrey Gumbs, Antonios Balassis, Danhong Huang
We calculated the effects of spin-orbit interaction (SOI) on the energy bands, ballistic conductance and the electron-diffusion thermoelectric power of a nanowire by varying the te…
Ab initio calculation of low-energy collective charge-density excitations in MgB2
V. M. Silkin, A. Balassis, P. M. Echenique +1
We present {\it ab-initio} time-dependent density-functional theory calculation results for low-energy collective electron excitations in . The existence of a long-…