126 research outputs found
Soliton physics with semiconductor exciton–polaritons in confined systems
In the past decade, there has been a significant progress in the study of non-linear
polariton phenomena in semiconductor microcavities. One of the key features of nonlinear
systems is the emergence of solitons. The complexity and the inherently strong
nonlinearity of the polariton system made it a perfect sandpit for observing solitonic
effects in half-light half-matter environment. This review focuses on the theory and the
latest experimental elucidating physics as well as potential applications of conservative
and dissipative solitons in exciton–polariton systems
Vortices in resonant polariton condensates in semiconductor microcavities
Covering general theoretical concepts and the research to date, this book demonstrates that Bose-Einstein condensation is a truly universal phenomenon
Polarization bistability and resultant spin rings in semiconductor microcavities
The transmission of a pump laser resonant with the lower polariton branch of
a semiconductor microcavity is shown to be highly dependent on the degree of
circular polarization of the pump. Spin dependent anisotropy of
polariton-polariton interactions allows the internal polarization to be
controlled by varying the pump power. The formation of spatial patterns, spin
rings with high degree of circular polarization, arising as a result of
polarization bistability, is observed. A phenomenological model based on spin
dependent Gross-Pitaevskii equations provides a good description of the
experimental results. Inclusion of interactions with the incoherent exciton
reservoir, which provides spin-independent blueshifts of the polariton modes,
is found to be essential.Comment: 5 pages, 3 figure
Backward Cherenkov radiation emitted by polariton solitons in a microcavity wire
Exciton-polaritons in semiconductor microcavities form a highly nonlinear platform to study a variety of effects interfacing optical, condensed matter, quantum and statistical physics. We show that the complex polariton patterns generated by picosecond pulses in microcavity wire waveguides can be understood as the Cherenkov radiation emitted by bright polariton solitons, which is enabled by the unique microcavity polariton dispersion, which has momentum intervals with positive and negative group velocities. Unlike in optical fibres and semiconductor waveguides, we observe that the microcavity wire Cherenkov radiation is predominantly emitted with negative group velocity and therefore propagates backwards relative to the propagation direction of the emitting soliton. We have developed a theory of the microcavity wire polariton solitons and of their Cherenkov radiation and conducted a series of experiments, where we have measured polariton-soliton pulse compression, pulse breaking and emission of the backward Cherenkov radiation
Publisher's Note: Logic gates with bright dissipative polariton solitons in Bragg cavity systems [Phys. Rev. B 92, 174528 (2015)]
Spatiotemporal continuum generation in polariton waveguides.
We demonstrate the generation of a spatiotemporal optical continuum in a highly nonlinear exciton-polariton waveguide using extremely low excitation powers (2-ps, 100-W peak power pulses) and a submillimeter device suitable for integrated optics applications. We observe contributions from several mechanisms over a range of powers and demonstrate that the strong light-matter coupling significantly modifies the physics involved in all of them. The experimental data are well understood in combination with theoretical modeling. The results are applicable to a wide range of systems with linear coupling between nonlinear oscillators and particularly to emerging polariton devices that incorporate materials, such as gallium nitride and transition metal dichalcogenide monolayers that exhibit large light-matter coupling at room temperature. These open the door to low-power experimental studies of spatiotemporal nonlinear optics in submillimeter waveguide devices
Logic Gates with Bright Dissipative Polariton Solitons in Bragg-Cavity Systems
Optical solitons are an ideal platform for the implementation of communication lines, since they can be packed extremely close one to another without risking partial loss of the encoded information due to their interaction. On the other hand, soliton-soliton interactions are needed to implement computations and achieve all-optical information processing. Here we study how bright dissipative polariton solitons interact and exploit their interaction to implement AND and OR gates with state of the art technology. Moreover, we show that soliton-soliton interaction can be used to determine the sign of {\alpha}2, the parameter describing the interaction between polaritons with opposite spin
Recommended from our members
Spatial patterns of dissipative polariton solitons in semiconductor microcavities
We report propagating bound microcavity polariton soliton arrays consisting of multipeak structures
either along (x) or perpendicular (y) to the direction of propagation. Soliton arrays of up to five solitons are
observed, with the number of solitons controlled by the size and power of the triggering laser pulse. The
breakup along the x direction occurs when the effective area of the trigger pulse exceeds the characteristic
soliton size determined by polariton-polariton interactions. Narrowing of soliton emission in energymomentum
space indicates phase locking between adjacent solitons, consistent with numerical modeling
which predicts stable multihump soliton solutions. In the y direction, the breakup originates from
inhomogeneity across the wave front in the transverse direction which develops into a stable array only in
the solitonic regime via phase-dependent interactions of propagating fronts
Publisher's Note: Logic gates with bright dissipative polariton solitons in Bragg cavity systems [Phys. Rev. B 92, 174528 (2015)]
Effect of the GaAsP shell on optical properties of self-catalyzed GaAs nanowires grown on silicon
We realize growth of self-catalyzed core-shell GaAs/GaAsP nanowires (NWs) on
Si substrates using molecular-beam epitaxy. Transmission electron microscopy
(TEM) of single GaAs/GaAsP NWs confirms their high crystal quality and shows
domination of the zinc-blende phase. This is further confirmed in optics of
single NWs, studied using cw and time-resolved photoluminescence (PL). A
detailed comparison with uncapped GaAs NWs emphasizes the effect of the GaAsP
capping in suppressing the non-radiative surface states: significant PL
enhancement in the core-shell structures exceeding 2000 times at 10K is
observed; in uncapped NWs PL is quenched at 60K whereas single core-shell
GaAs/GaAsP NWs exhibit bright emission even at room temperature. From analysis
of the PL temperature dependence in both types of NW we are able to determine
the main carrier escape mechanisms leading to the PL quench
- …