138 research outputs found
Exciton-Polariton Oscillations in Real Space
We introduce and model spin-Rabi oscillations based on exciton-polaritons in
semiconductor microcavities. The phase and polarization of oscillations can be
controlled by resonant coherent pulses and the propagation of oscillating
domains gives rise to phase-dependent interference patterns in real space. We
show that interbranch polariton-polariton scattering controls the propagation
of oscillating domains, which can be used to realize logic gates based on an
analogue variable phase.Comment: 6 page
Spontaneous polariton currents in periodic lateral chains
We predict spontaneous generation of superfluid polariton currents in planar
microcavities with lateral periodic modulation of both potential and decay
rate. A spontaneous breaking of spatial inversion symmetry of a polariton
condensate emerges at a critical pumping, and the current direction is
stochastically chosen. We analyse the stability of the current with respect to
the fluctuations of the condensate. A peculiar spatial current domain structure
emerges, where the current direction is switched at the domain walls, and the
characteristic domain size and lifetime scale with the pumping power.Comment: 6+6 pages, 4+1 figures (with supplemental material
Stochastic polarization formation in exciton-polariton Bose-Einstein condensates
We demonstrate theoretically the spontaneous formation of a stochastic
polarization in exciton-polariton Bose-Einstein condensates in planar
microcavities under pulsed excitation. Below the threshold pumping intensity
(dependent on the polariton life-time) the average polarization degree is close
to zero, whilst above threshold the condensate acquires a polarization
described by a (pseudospin) vector with random orientation, in general. We
establish the link between second order coherence of the polariton condensate
and the distribution function of its polarization. We examine also the
mechanisms of polarization dephasing and relaxation.Comment: 4 pages, 3 figure
Pseudo diamagnetism of four component exciton condensates
We analyze the spin structure of the ground state of four-component exciton
condensates in coupled quantum wells as a function of spin-dependent
interactions and applied magnetic field. The four components correspond to the
degenerate exciton states characterized by and spin projections
to the axis of the structure. We show that in a wide range of parameters, the
chemical potential of the system increases as a function of magnetic field,
which manifests a pseudo-diamagnetism of the system. The transitions to
polarized two- and one-component condensates can be of the first-order in this
case. The predicted effects are caused by energy conserving mixing of
and excitons.Comment: 4 pages, 2 figure
Exciton-photon correlations in bosonic condensates of exciton-polaritons
Exciton-polaritons are mixed light-matter quasiparticles. We have developed a
statistical model describing stochastic exciton-photon transitions within a
condensate of exciton polaritons. We show that the exciton-photon correlator
depends on the "hidden variable" which characterizes the rate of exciton-photon
transformations in the condensate. We discuss implications of this effect for
the quantum statistics of photons emitted by polariton lasers.Comment: 5 pages, 2 figure
Pseudoconservative dynamics of coupled polariton condensates
© 2021 The Authors. Published by American Physical Society. This is an open access article available under a Creative Commons licence.
The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1103/PhysRevResearch.3.033187Open-dissipative systems obeying parity-time (PT) symmetry are capable of demonstrating oscillatory dynamics akin to the conservative systems. In contrast to limit cycle solutions characteristic of nonlinear systems, the PT-symmetric oscillations form a continuum of nonisolated orbits. However, precise sculpturing of the real potential and the gain-loss spatial profiles required for establishing of the PT symmetry is practically challenging. The optical devices, such as lasers, exhibit relaxation dynamics and do not operate as the PT-symmetric systems. Here we demonstrate how these constraints can be overcome. We predict that a pair of optically trapped polariton condensates (a polariton dimer) can be excited and operated in the oscillating regime typical of the isolated systems. This regime can be realized in the presence of both dissipative and conservative coupling between the condensates and can be maintained at an arbitrary external pump intensity. Every orbit is characterized by a frequency comb appearing in the spectrum of a dimer in the presence of the conservative nonlinearity. Our results pave the way for the creation of the optical computing devices operating under the constant-wave external pumping.Published versio
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