Murat Tas

Quasiparticle band structure of the almost-gapless transition-metal-based Heusler semiconductors

Transition-metal-based Heusler semiconductors are promising materials for a variety of applications ranging from spintronics to thermoelectricity. Employing the

Thermoelectric power of nondegenerate Kane semiconductors under the conditions of mutual electron-phonon drag in a high electric field

GW

Unidirectional invisibility and PT symmetry with graphene

approximation within the framework of the FLAPW method, we study the quasi-particle band structure of a number of such compounds being almost gapless semiconductors. We find that in contrast to the \textit{sp}-electron based semiconductors such as Si and GaAs, in these systems the many-body corrections have a minimal effect on the electronic band structure and the energy band gap increases by less than 0.2~eV, which makes the starting point density functional theory (DFT) a good approximation for the description of electronic and optical properties of these materials. Furthermore, the band gap can be tuned either by the variation of the lattice parameter or by the substitution of the \emph{sp}-chemical element.

Collective excitations of strongly coupled bilayer charged Bose liquids in the third-frequency-moment sum rule

The thermoelectric power of nondegenerate Kane semiconductors with due regard for the electron and phonon heating and their thermal and mutual drags is investigated. The electron spectrum is taken in the Kane two-band form. It is shown that the nonparabolicity of electron spectrum significantly influences the magnitude of the thermoelectric power and leads to a change of its sign and dependence on the heating electric field. The field dependence of the thermoelectric power is determined analytically under various drag conditions.

Ionization energies, Coulomb explosion, fragmentation, geometric, and electronic structures of multicharged boron clusters B(n) (n=2-13)

We investigate the reflectionlessness and invisibility properties in the transverse electric (TE) mode solution of a linear homogeneous optical system which comprises the

Phase transition in compact QED3 and the Josephson junction

\mathcal{PT}

Short-range correlations in a one-dimensional electron gas

-symmetric structures covered by graphene sheets. We derive analytic expressions, indicate roles of each parameter governing optical system with graphene and justify that optimal conditions of these parameters give rise to broadband and wide angle invisibility. Presence of graphene turns out to shift the invisible wavelength range and to reduce the required gain amount considerably, based on its chemical potential and temperature. We substantiate that our results yield broadband reflectionless and invisible configurations for realistic materials of small refractive indices, usually around

Spin-correlation effects in a one-dimensional electron gas

\eta = 1

Fragmentation and Coulomb explosion of multicharged small boron clusters

, and of small thickness sizes with graphene sheets of rather small temperatures and chemical potentials. Finally, we demonstrate that pure

Influence of mutual drag of the carrier-phonon system on the thermopower and transverse Nernst-Ettingshausen effect

\mathcal{PT}