Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userPolariton pattern formation and photon statistics of the associated emission
69
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We report on the formation of a diverse family of transverse spatial polygon patterns in a microcavity polariton fluid under coherent driving by a blue-detuned pump. Patterns emerge spontaneously as a result of energy-degenerate polariton-polariton scattering from the pump state to interfering high order vortex and antivortex modes, breaking azimuthal symmetry. The interplay between a multimode parametric instability and intrinsic optical bistability leads to a sharp spike in the value of second order coherence $g^{(2)}(0)$ of the emitted light, which we attribute to the strongly superlinear kinetics of the underlying scattering processes driving the formation of patterns. We show numerically by means of a linear stability analysis how the growth of parametric instabilities in our system can lead to spontaneous symmetry breaking, predicting the formation and competition of different pattern states in good agreement with experimental observations.
rate research
Read More
Using a high-quality GaAs planar microcavity, we optically generate polariton pairs, and verify their correlations by means of time-resolved single-photon detection. We find that correlations between the different modes are consistently lower than identical mode correlations, which is attributed to the presence of uncorrelated background. We discuss a model to quantify the effects of such a background on the observed correlations. Using spectral and temporal filtering, the background can be suppressed and a change in photon statistics towards non-classical correlations is observed. These results improve our understanding of the statistics of polariton-polariton scattering and background mechanisms, and pave the way to the generation of entangled polariton pairs.
Polariton condensation can be regarded as a self-organization phenomenon, where phase ordering is established among particles in the system. In such condensed systems, further ordering can possibly occur in the particle density distribution, under particular experimental conditions. In this work we report on spontaneous pattern formation in a polariton condensate under non-resonant optical pumping. The slightly elliptical ring-shaped excitation laser we employ is such to force condensation to occur in a single-energy state with periodic boundary conditions, giving rise to a multi-lobe standing wave patterned state.
We investigate the statistics of photons emitted by tunneling electrons in a single electronic level plasmonic nanojunction. We compute the waiting-time distribution of successive emitted photons $w(tau)$. When the cavity damping rate $kappa$ is larger than the electronic tunneling rate $Gamma$, we show that in the photon-antibunching regime, $w(tau)$ indicates that the average delay-time between two successive photon emission events is given by $1/Gamma$. This is in contrast with the usually considered second-order correlation function of emitted photons, $g^{(2)}(tau)$, which displays the single time scale $1/kappa$. Our analysis shows a relevant example for which $w(tau)$ gives independent information on the photon-emission statistics with respect to $g^{(2)}(tau)$, leading to a physical insight on the problem. We discuss how this information can be extracted from experiments even in presence of a non-perfect photon detection yield.
We observe for the first time two-photon excited condensation of exciton-polaritons. The angle-resolved photoluminescence (PL) from the Lower Polariton (LP) ground state in our planar GaAs-based microcavity structure exhibits a clear intensity threshold as a function of increased two-photon excitation power, coinciding with an interaction-induced blueshift and a narrowing of spectral linewidth, characteristic of the transition from a thermal distribution of lower polaritons to polariton condensation. Two-Photon Absorption (TPA) is evidenced in the quadratic dependence of the input-output curves below and above the threshold region. Second Harmonic Generation (SHG) is ruled out by both this threshold behavior and by scanning the pump photon energy and observing a lack of dependence of the LP emission peak energy. Our results pave the way towards realization of a polariton-based stimulated THz radiation source, stemming from the dipole-allowed transition from the Quantum Well (QW) 2p dark exciton state to the 1s-exciton-based LP ground state, as theoretically predicted in [A. V. Kavokin et al., Phys. Rev. Lett. 108, 197401 (2012)].
We report on the simultaneous observation of spontaneous symmetry breaking and long-range spatial coherence both in the strong and the weak-coupling regime in a semiconductor microcavity. Under pulsed excitation, the formation of a stochastic order parameter is observed in polariton and photon lasing regimes. Single-shot measurements of the Stokes vector of the emission exhibit the buildup of stochastic polarization. Below threshold, the polarization noise does not exceed 10%, while above threshold we observe a total polarization of up to 50% after each excitation pulse, while the polarization averaged over the ensemble of pulses remains nearly zero. In both polariton and photon lasing regimes, the stochastic polarization buildup is accompanied by the buildup of spatial coherence. We find that the Landau criterion of spontaneous symmetry breaking and Penrose-Onsager criterion of long-range order for Bose-Einstein condensation are met in both polariton and photon lasing regimes.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
