102 research outputs found
Nonlinear Terahertz Emission in Semiconductor Microcavities
We consider the nonlinear terahertz emission by the system of cavity
polaritons in the regime of polariton lasing. To account for the quantum nature
of terahertz-polariton coupling we use the Lindblad master equation approach
and demonstrate that quantum microcavities reveal rich variety of the nonlinear
phenomena in terahertz range, including bistability, short THz pulse generation
and THz switching.Comment: 4 pages + 5 figures + Supplementary Material. (Final version
containing the derivation of the kinetic equations.
Rashba plasmon polaritons in semiconductor heterostructures
We propose a concept of surface plasmon-polariton amplification in the
structure comprising interface between dielectric, metal and asymmetric quantum
well. Due to the Rashba spin-orbit interaction, mimina of dispersion relation
for electrons in conduction band are shifted with respect to the maximum of
dispersion dependence for holes in -point. When energy and momentum
intervals between extrema in dispersion relations of electrons and holes match
dispersion relation of plasmons, indirect radiative transition can amplify the
plasmons; excitation of leaky modes is forbidden due to the selection rules.
Efficiency of the indirect radiative transition is calculated and design of the
structure is analysed.Comment: Published (4 pages + 3 figures), 2nd proof versio
Gap solitons in quasiperiodic optical lattices
Families of solitons in one- and two-dimensional (1D and 2D) Gross-Pitaevskii
equations with the repulsive nonlinearity and a potential of the
quasicrystallic type are constructed (in the 2D case, the potential corresponds
to a five-fold optical lattice). Stable 1D solitons in the weak potential are
explicitly found in three bandgaps. These solitons are mobile, and they collide
elastically. Many species of tightly bound 1D solitons are found in the strong
potential, both stable and unstable (unstable ones transform themselves into
asymmetric breathers). In the 2D model, families of both fundamental and
vortical solitons are found and are shown to be stable.Comment: 8 pages, 11 figure
Bragg Polaritons: Strong Coupling and Amplification in an Unfolded Microcavity
Periodic incorporation of quantum wells inside a one--dimensional Bragg
structure is shown to enhance coherent coupling of excitons to the
electromagnetic Bloch waves. We demonstrate strong coupling of quantum well
excitons to photonic crystal Bragg modes at the edge of the photonic bandgap,
which gives rise to mixed Bragg polariton eigenstates. The resulting Bragg
polariton branches are in good agreement with the theory and allow
demonstration of Bragg polariton parametric amplification.Comment: 4 pages, 4 figure
Electric generation of vortices in an exciton-polariton superfluid
We have theoretically demonstrated the on demand electric generation of
vortices in an exciton-polariton superfluid. Electric pulses applied to a
horseshoe-shaped metallic mesa, deposited on top of the microcavity, generate a
non-cylindrically symmetric solitonic wave in the system. Breakdown of its
wavefront at focal points leads to the formation of vortex-antivortex pairs
which subsequently propagate in the superfluid. The trajectory of these vortex
dipoles can be controlled by applying a voltage to additional electrodes. They
can be confined within channels formed by metallic stripes and unbound by a
wedged mesa giving birth to grey solitons. Finally single static vortices can
be generated using a single metallic plate configuration.Comment: 7 pages and 7 figure
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