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Localized exciton polaritons excited by multiple non-resonant injections a–c, The integrated angle-resolved spectra for single-pulse injection below (a) and above (b) the condensation threshold, and for two successive pulse injections (c) at a delay of 5 ps. The fluence of each pulse is kept at about 0.6Fth. d, Spectra for two pulse injections as a function of the time delay. Condensation can be achieved within a delay of about 120 ps. e, Time-resolved photoluminescence intensity obtained for the indicated relative delays. The light blue dashed line represents the arrival of the first excitation pulse at zero time delay. The dashed lines of other colours indicate the arrival time of the second excitation laser pulses. f, The linewidth and buildup time of the resulting condensation signals for bi-injection at various delays. Error bars are estimated from the experimental instability (n = 3). g, Simulation results based on solving the open-dissipative GP equation. The light blue dashed line indicates the injection of the first laser pulse at zero time delay. The dark blue curve shows the dynamics of exciton density where the sudden enhancement at about 20 ps is induced by the second pulse injection (marked by the purple dashed line). The red curve represents the time-resolved EP population produced by stimulated amplification. ∣ψ∣² is the density of the lower polariton mode, which is presented by a magnification of 70 times for better comparison. nR represents the calculated density of the exciton reservior. h, Threshold behaviours as a function of the second injection fluence with delays of 10, 40 and 70 ps, respectively. The dark yellow curve represents a single-pulse injection scenario.
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Exciton polaritons—quasi-particle excitations consisting of strongly coupled photons and excitons—present fascinating possibilities for photonic circuits, owing to their strong nonlinearity, ultrafast reaction times and their ability to form macroscopic quantum states at room temperature via non-equilibrium condensation. Past implementations of tra...
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Polaritons, arising from the strong coupling between excitons and photons within microcavities, hold promise for optoelectronic and all-optical devices. They have found applications in various domains, including low-threshold lasers and quantum information processing. To realize complex functionalities, non-intuitive designs for polaritonic devices...
Citations
... This research uncovers new physical phenomena, such as quantum entanglement and chiral quantum light fields [11], while also offering practical implications for the advancement of cuttingedge optoelectronic devices and quantum information technologies. Chiral exciton-polaritons, for instance, hold potential for realizing all-optical switches [12]- [14], optical logic gates [15], novel quantum light sources [16], [17], and optical isolators [18], furthering advancements in quantum computing and communication. ...
Chirality of exciton-polaritons can be tuned by the chirality of photons, excitons, and their coupling strength. In this work, we propose a general analytical model based on coupled harmonic oscillators to describe the chirality of exciton-polaritons. Our model predicts the degree of circular polarization (DCP) of exciton-polaritons, which is determined by the DCPs and weight fractions of the constituent excitons and photons. At the anticrossing point, the DCP of exciton-polaritons is equally contributed from both constituents. Away from the anticrossing point, the DCP of exciton-polaritons relaxes toward the DCP of the dominant constituent, with the relaxation rate decreasing as the coupling strength increases. We validate our model through simulations of strongly coupled topological edge states and excitons, showing good agreement with model predictions. Our model provides a valuable tool for designing the chirality of strong coupling systems and offers a framework for the inverse design of exciton-polaritons with tailored chirality.
... The photonic component of polariton results in an ultra-low effective mass, leading to excellent transport properties, when the excitonic component of polaritons gives rise to significant interparticle interactions. From the perspective of applications, polaritons have been used for creating optical lattices 17 , simulators 18,19 , energy-efficient, ultrafast optical switches 20,21 , logic gates [22][23][24] , routers 25 , transistors 26, 27 , and neural networks 9,10 . Nevertheless, neural network implementations have been limited to cryogenic temperatures. ...
Limitations of electronics have stimulated the search for novel unconventional computing platforms that enable energy-efficient and ultra-fast information processing. Among various systems, exciton-polaritons stand out as promising candidates for the realization of optical neuromorphic devices. This is due to their unique hybrid light-matter properties, resulting in strong optical nonlinearity and excellent transport capabilities. However, previous implementations of polariton neural networks have been restricted to cryogenic temperatures, limiting their practical applications. In this work, using non-equillibrium Bose-Einstein condensation in a monocrystalline perovskite waveguide, we demonstrate the first room-temperature exciton-polariton neural network. Its performance is verified in various machine learning tasks, including binary classification, and object detection. Our result is a crucial milestone in the development of practical applications of polariton neural networks and provides new perspectives for optical computing accelerators based on perovskites.
Lead halide perovskites exhibit superior properties compared to classical III–V semiconductor quantum wells for room‐temperature polaritonic applications, particularly owing to the significant crystalline anisotropy. This anisotropy results in a sizeable split in condensate energy, which can profoundly influence polariton interactions and spin relaxation pathways. Besides, trapped exciton‐polariton (TEP) exhibits a quantized energy landscape, which is essential for modulating polaritonic logical circuits. Herein, spin‐orbit coupled TEP lasing is demonstrated in birefringent perovskite. Cascade condensate processes between orthogonally polarized polariton branches happen considering the dominance of reservoir exciton–polariton or polariton–polariton scattering within each stage. Such condensation adequately is verified via the input‐output “S” curve, the narrowed linewidth, the energy blueshift, and the real space spatial coherence of the orthogonally polarized modes. This trapped anisotropic condensate holds great promise for room‐temperature polaritonic and spintronics.
