arXiv subjects

V. E. Bisti

Publications and source records attributed to V. E. Bisti.

3 recordsLinked to original sources

arXiv2016

Artificially constructed plasmaron and plasmon-exciton molecule in 2D-metals

Resonant optical excitation was used to create a macroscopic non-equilibrium ensemble of dark excitons with unprecedentedly long lifetime in a two-dimensional (2D) electron system placed in a quantizing magnetic field. Exotic three-particle and four-particle states, plasmarons and plasmon-exciton molecules, coupled with the surrounding electrons through the collective plasma oscillations are engineered. Plasmarons and plasmon-exciton molecules are manifested as new features in the recombination spectra of non-equilibrium systems. Magnetoplasmarons and magnetotrions in a two-dimensional Hall insulator.

cond-mat.mes-hall↗

arXiv2011

Coulomb interaction and electron-hole asymmetry in cyclotron resonance of bilayer graphene in high magnetic field

Inter-Landau-level transitions in the bilayer graphene at high perpendicular magnetic field at the filling-factor v<<1 have been studied. The next-nearest-neighbor transitions, energy difference between dimer and non-dimer sites and layer asymmetry are included. The influence of Coulomb interaction is taken into account. The magnetoplasmon excitations in bilayer graphene at small momenta are considered in the frame of the Hartree-Fock approximation. It is shown that asymmetry in cyclotron resonance of clean bilayer graphene depends on magnetic field. At lower magnetic fields the energy splitting in the spectrum is due to electron-hole one-particle asymmetry, at higher magnetic fields the energy splitting in the spectrum is due to Coulomb interaction. For the fullsymmetric case with half-filled zero-energy levels the energy splitting proportional to the energy of Coulomb interaction is found both for bilayer and monolayer graphene.

cond-mat.mes-hall↗

arXiv2005

Coherent spin dynamics of an interwell excitons gas in GaAs/AlGaAs coupled quantum wells

The spin dynamics of an interwell excitons gas has been investigated in n-i-n GaAs/AlGaAs coupled quantum wells (CQWs). In these heterostructures the electron and the hole are spatially separated in neighboring quantum wells by a narrow AlAs barrier, when an electric field is applied. The time evolution kinetics of the interwell exciton photoluminescence has been measured under resonant excitation of the 1sHH intrawell exciton, using a pulsed tunable laser. The formation of a collective exciton phase in time and the temperature dependence of its spin relaxation rate have been studied. The spin relaxation rate of the interwell excitons is strongly reduced in the collective phase. This observation provides evidence for the coherence of the indirect excitons collective phase at temperatures below a critical $T_c$.

cond-mat.mes-hall↗