158 research outputs found
Switching waves in multi-level incoherently driven polariton condensates
We show theoretically that an open-dissipative polariton condensate confined
within a trapping potential and driven by an incoherent pumping scheme gives
rise to bistability between odd and even modes of the potential. Switching from
one state to the other can be controlled via incoherent pulsing which becomes
an important step towards construction of low-powered opto-electronic devices.
The origin of the effect comes from modulational instability between odd and
even states of the trapping potential governed by the nonlinear
polariton-polariton interactions
Parity solitons in nonresonantly driven-dissipative condensate channels
We study analytically and numerically the condensation of a
driven-dissipative exciton-polariton system using symmetric nonresonant pumping
geometries. We show that the lowest condensation threshold solution carries a
definite parity as a consequence of the symmetric excitation profile. At higher
pump intensities competition between the two parities can result in critical
quenching of one and saturation of the other. Using long pump channels, we show
that the competition of the condensate parities gives rise to a different type
of topologically stable defect propagating indefinitely along the condensate.
The defects display repulsive interactions and are characterized by a sustained
wavepacket carrying a pair of opposite parity domain walls in the condensate
channel
Time-Delay Polaritonics
Non-linearity and finite signal propagation speeds are omnipresent in nature,
technologies, and real-world problems, where efficient ways of describing and
predicting the effects of these elements are in high demand. Advances in
engineering condensed matter systems, such as lattices of trapped condensates,
have enabled studies on non-linear effects in many-body systems where exchange
of particles between lattice nodes is effectively instantaneous. Here, we
demonstrate a regime of macroscopic matter-wave systems, in which ballistically
expanding condensates of microcavity exciton-polaritons act as picosecond,
microscale non-linear oscillators subject to time-delayed interaction. The ease
of optical control and readout of polariton condensates enables us to explore
the phase space of two interacting condensates up to macroscopic distances
highlighting its potential in extended configurations. We demonstrate
deterministic tuning of the coupled-condensate system between fixed point and
limit cycle regimes, which is fully reproduced by time-delayed coupled
equations of motion similar to the Lang-Kobayashi equation
Enhanced coupling between ballistic exciton-polariton condensates through tailored pumping
We propose a method to enhance the spatial coupling between ballistic
exciton-polariton condensates in a semiconductor microcavity based on available
spatial light modulator technologies. Our method, verified by numerically
solving a generalized Gross-Pitaevskii model, exploits the strong
nonequilibrium nature of exciton-polariton condensation driven by localized
nonresonant optical excitation. Tailoring the excitation beam profile from a
Gaussian into a polygonal shape results in refracted and focused radial streams
of outflowing polaritons from the excited condensate which can be directed
towards nearest neighbors. Our method can be used to lower the threshold power
needed to achieve polariton condensation and increase spatial coherence in
extended systems, paving the way towards creating extremely large-scale quantum
fluids of light
EDSOA: An Event-Driven Service-Oriented Architecture Model For Enterprise Applications
Enterprise Applications are difficult to implement and maintain because they require a monolith of code to incorporate required business processes. Service-oriented architecture is one solution, but challenges of dependency and software complexity remain. We propose Event-Driven Service-Oriented Architecture, which combines the benefits of component-based software development, event-driven architecture, and SOA
Photonic Berry curvature in double liquid crystal microcavities with broken inversion symmetry
We investigate a photonic device consisting of two coupled optical cavities
possessing Rashba-Dresselhaus spin-orbit coupling, TE-TM splitting, and linear
polarisation splitting that opens a tuneable energy gap at the diabolic points
of the photon dispersion; giving rise to an actively addressable local Berry
curvature. The proposed architecture stems from recent advancements in the
design of artificial photonic gauge fields in liquid crystal cavities [K.
Rechci\'{n}ska et al., Science 366, 727 (2019)]. Our study opens new
perspectives for topological photonics, room-temperature spinoptronics, and
studies on the quantum geometrical structure of photonic bands in extreme
settings
Vortex clusters in a stirred polariton condensate
The response of superfluids to the external rotation, evidenced by emergence
of quantised vortices, distinguishes them from conventional fluids. In this
work, we demonstrate that the number of vortices in a stirred polariton
condensate depends on the characteristic size of the employed rotating
potential induced by the nonresonant laser excitation. For smaller sizes, a
single vortex with a topological charge of +-1 corresponding to the stirring
direction is formed. However, for larger optical traps, clusters of two or
three co-rotating vortices appear in the narrow range of GHz stirring speed
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