122 research outputs found
An acoustic black hole in a stationary hydrodynamic flow of microcavity polaritons
We report an experimental study of superfluid hydrodynamic effects in a
one-dimensional polariton fluid flowing along a laterally patterned
semiconductor microcavity and hitting a micron-sized engineered defect. At high
excitation power, superfluid propagation effects are observed in the polariton
dynamics, in particular, a sharp acoustic horizon is formed at the defect
position, separating regions of sub- and super-sonic flow. Our experimental
findings are quantitatively reproduced by theoretical calculations based on a
generalized Gross-Pitaevskii equation. Promising perspectives to observe
Hawking radiation via photon correlation measurements are illustrated.Comment: 5 pages Main + 5 pages Supplementary, 8 figure
Controlled light-matter coupling for a single quantum dot embedded in a pillar microcavity using far-field optical lithography
Using far field optical lithography, a single quantum dot is positioned
within a pillar microcavity with a 50 nm accuracy. The lithography is performed
in-situ at 10 K while measuring the quantum dot emission. Deterministic
spectral and spatial matching of the cavity-dot system is achieved in a single
step process and evidenced by the observation of strong Purcell effect.
Deterministic coupling of two quantum dots to the same optical mode is
achieved, a milestone for quantum computing.Comment: Modified version: new title, additional experimental data in figure
Field Localization and Enhancement of Phase Locked Second and Third Harmonic Generation in Absorbing Semiconductor Cavities
We predict and experimentally observe the enhancement by three orders of
magnitude of phase mismatched second and third harmonic generation in a GaAs
cavity at 650nm and 433nm, respectively, well above the absorption edge. Phase
locking between the pump and the harmonics changes the effective dispersion of
the medium and inhibits absorption. Despite hostile conditions the harmonics
become localized inside the cavity leading to relatively large conversion
efficiencies. Field localization plays a pivotal role and ushers in a new class
of semiconductor-based devices in the visible and UV ranges
Nonlinear Polariton Fluids in a Flatband Reveal Discrete Gap Solitons
Phase frustration in periodic lattices is responsible for the formation of
dispersionless flat bands. The absence of any kinetic energy scale makes flat
band physics critically sensitive to perturbations and interactions. We report
here on the experimental investigation of the nonlinear dynamics of cavity
polaritons in the gapped flat band of a one-dimensional Lieb lattice. We
observe the formation of gap solitons with quantized size and very abrupt
edges, signature of the frozen propagation of switching fronts. This type of
gap solitons belongs to the class of truncated Bloch waves, and had only been
observed in closed systems up to now. Here the driven-dissipative character of
the system gives rise to a complex multistability of the nonlinear domains
generated in the flat band. These results open up interesting perspective
regarding more complex 2D lattices and the generation of correlated photon
phases.Comment: 6 pages, 4 figures + supplemental material (6 pages, 6 figures
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