Найдено научных статей и публикаций: 1, для научной тематики: Low-dimensional electronic systems
1.
E. V. Dumanov, M. A. Liberman, S. A. Moskalenko, B. V. Novikov, and S. S. Rusu
- WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim , 2012
The collective elementary excitations of the two-dimensional
(2D) magnetoexcitons in the state of their Bose–Einstein
condensation (BEC) with nonzero wave vector k and inplane
parallel oriented motional dipole moments are investigated
in the Hartree–Fock–Bogoliubov approximation (HFBA).
The breaking...
The collective elementary excitations of the two-dimensional
(2D) magnetoexcitons in the state of their Bose–Einstein
condensation (BEC) with nonzero wave vector k and inplane
parallel oriented motional dipole moments are investigated
in the Hartree–Fock–Bogoliubov approximation (HFBA).
The breaking of the gauge symmetry is achieved using the
Bogoliubov theory of quasiaverages and the Keldysh–Kozlov–
Kopaev (KKK) method. The starting Hamiltonian and the
Green’s functions are determined using the integral twoparticle
operators instead of the single-particle Fermi operators.
The infinite chains of equations of motion for the multioperator
four- and six-particle Green-s functions are truncated following
the Zubarev method and introducing a small parameter of
the perturbation theory related with the lowest Landau levels
(LLLs) filling factor and with the phase-space filling factor.
The energy spectrum of the collective elementary excitations
consists of the mixed exciton–plasmon energy braches, mixed
exciton–plasmon quasienergy branches as well as the optical
and acoustical plasmon energy branches. The exciton branches
of the spectrum have gaps related with the negative values of
the chemical potential and attractive interaction between the
2D megnetoexcitons with inplane, parallel oriented motional
dipole moments. The slopes of the mixed exciton–plasmon
branches are determined by the group velocities of the moving
condensed excitons in the laboratory reference frame. The
acoustical and optical plasmon energy branches are gapless.
Their dependence on the small wave vectors accounted from the
condensate wave vector k is linear and quadratic, respectively,
with saturation in the range of high values of the wave vectors.
Phys. Status Solidi B 250, No. 1, 115–127 (2013)