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Recent Progress of Strong Exciton-Photon Coupling in Lead Halide Perovskites
摘要： The semiconductor exciton–polariton, arising from the strong coupling between excitons and confined cavity photon modes, is not only of fundamental importance in macroscopic quantum effects but also has wide application prospects in ultralow-threshold polariton lasers, slowing-light devices, and quantum light sources. Very recently, metallic halide perovskites have been considered as a great candidate for exciton–polariton devices owing to their low-cost fabrication, large exciton oscillator strength, and binding energy. Herein, the latest progress in exciton–polaritons and polariton lasers of perovskites are reviewed. Polaritons in planar and nanowires Fabry–Pérot microcavities are discussed with particular reference to material and photophysics. Finally, a perspective on the remaining challenges in perovskite polaritons research is given.
关键词： exciton–polariton,low threshold laser,lead halide perovskite,optical microcavity,strong light–matter interaction
更新于2025-09-23 15:21:01
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Multi-electron anisotropic quantum dots/TMDCs/CNT families under magnetic field: analytical treatment to first Brillouin zone by Fermi liquid model
摘要： Acute Coulomb interaction of the two-dimensional systems has drawn special attention due to its unusual logarithmic Green function expansion. As the number of electrons (N) increases, Pauli Exclusion principle emerges inevitably with rapidly growing electronic correlations. Quantum dot, Transition metal dichalcogenides (TMDC) and Carbon nanotube (CNT) families of 2-D anisotropic mesoscopic systems are rich habitats of electrons. Schr?dinger equations of such electrons in electrical confinement and transverse magnetic field can be recast in self-adjoint Whittaker-M functions facilitating each Coulomb interaction to terminable, exact and single summed Lauricella function via Chu-Vandermonde identity. For N = 3, 4, 5, 6, . . . 20, multipoles of Green function expansion also succumb to terminable, single-summed, analytical integrals by inserting discretised closure relations. Thus, multi-configuration Slater determinantal states are employed for strong correlation of Fermi liquid model of first Brillouin zone (FBZ) within giga-units of reciprocal lattices (mesoscopic scale). Chemical potential, addition energies of WS2, GaAs and model systems of dielectric constant = 1.0 have set benchmark at low and high confinement potentials, as a function of magnetic field and density of electrons. Because of sharp falls in surface integrals of both Newman and Dirichlet forms of Green function, Coulomb interaction takes to (or leads to) multipole expansion of generic coordinates. Formation of composite-fermions may be anticipated. At the most, octupole is sufficient for the convergence.
关键词： Lauricella Functions,multi-configuration slater determinant,Fermi liquid model,strong Coulomb interaction,quantum dots/TMDC
更新于2025-09-23 15:21:01
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Direct in situ TEM visualization and insight of the facet-dependent sintering behaviours of gold on TiO?
摘要： To prevent sintering of supported nanocatalysts is an important issue in nanocatalysis. A feasible way is to choose a suitable support. However, whether the metal-support interactions promote or prevent the sintering has not been fully identified due to the lack of confirmed evidences. Herein, we report on completely different sintering behaviours of Au nanoparticles on distinct anatase TiO2 surfaces by in situ TEM. The full in situ sintering processes of Au nanoparticles were visualized on TiO2 (101) surface, which coupled the Ostwald ripening and particle migration coalescence. In contrast, no sintering of Au on TiO2 anatase (001) surface was observed under the same conditions. This facet-dependent sintering mechanism is fully explained by the density function theory calculations. Our work not only offers the direct evidence of the important role of supports in the sintering process, but also provides insightful information for the design of sintering-resistant nanocatalysts.
关键词： in situ TEM,particle migration and coalescence (PMC),sintering,metal?support interaction (MSI),Au-TiO2,Ostwald ripening (OR)
更新于2025-09-23 15:21:01
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Non-Fourier Estimate of Electron Temperature in Case of Femtosecond Laser Pulses Interaction with Metals
摘要： This work is devoted to the electron temperature variation in metals through interaction with femtosecond laser pulses. Our study was inspired by the last mathematical breakthroughs regarding the exact analytical solutions of the heat equation in the case of flash laser-matter interaction. To this purpose, the classical Anisimov’s two temperature model was extended via the 3D telegraph Zhukovsky equation. Based upon this new approach, the computational plots of electron thermal fields during the first laser pulse interaction with a gold surface were inferred. It is shown that relaxation times and coupling factors over electron thermal conductivities (g/K) govern the interaction between the laser pulse and metal sample during the first picoseconds. The lower the factor g/K, the higher the electron temperature becomes. In contrast, the lower the relaxation time, the lower the electron temperature.
关键词： two temperature model,3D telegraph equation,femtosecond lasers-metal interaction,metals
更新于2025-09-23 15:21:01
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Detecting task demand via an eye tracking machine learning system
摘要： Computerized systems play a significant role in today’s fast-paced digital economy. Because task demand is a major factor that influences how computerized systems are used to make decisions, identifying task demand automatically provides an opportunity for designing advanced decision support systems that can respond to user needs at a personalized level. A first step for designing such advanced decision tools is to investigate possibilities for developing automatic task load detectors. Grounded in decision making, eye tracking, and machine learning literature, we argue that task demand can be detected automatically, reliably, and unobtrusively using eye movements only. To investigate this possibility, we developed an eye tracking task load detection system and tested its effectiveness. Our results revealed that our task load detection system reliably predicted increased task demand from users’ eye movement data. These results and their implications for research and practice are discussed.
关键词： task demand,human computer interaction,cognitive effort,adaptive decision making,eye tracking,machine learning
更新于2025-09-23 15:21:01
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Appropriate Molecular Interaction Enabling Perfect Balance Between Induced Crystallinity and Phase Separation for Efficient Photovoltaic Blends
摘要： Fluorination is a promising modification method to adjust the photophysical profiles of organic semiconductors. Notably, the fluorine modification on donor or acceptor materials could impact the molecular interaction, which is strongly related to the morphology of bulk heterojunction (BHJ) blends and the resultant device performance. Therefore, it’s essential to investigate how the molecular interaction affect the morphology of BHJ films. In this study, a new fluorinated polymer PBDB-PSF is synthesized to investigate the molecular interaction in both nonfluorinated (ITIC) and fluorinated (IT-4F) systems. The results reveal that the F-F interaction in PBDB-PSF:IT-4F system could effectively induce the crystallization of IT-4F while retaining ideal phase separation scale, resulting in outstanding charge transport. On the contrary, poor morphology can be observed in PBDB-PSF:ITIC system due to the unbalanced molecular interaction. As a consequence, the PBDB-PSF:IT-4F device delivers an excellent PCE of 13.63%, which greatly exceeds PBDB-PSF:ITIC device (9.84%). These results highlight manipulating the micromorphology in regard of molecular interaction.
关键词： induced crystalline,molecular interaction,phase separation,fluorination,synergistic effect
更新于2025-09-23 15:21:01
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Parametric study of ultra-intense laser interaction with uniform and nano-porous near-critical plasmas
摘要： Responses of the uniform near-critical plasma (UNCP) and nano-porous near-critical plasma (NPNCP) upon interaction with a short-intense laser have been scrutinized using two-dimensional (2D) particle-in-cell simulations. Maximum proton energy variation by the deposition of uniform and nano-porous layers in front of a solid target for a wide range of laser intensities (normalized amplitude a0 = 5–25) and average densities of the front layer ne = 0.3 ? 3nc (where nc is the critical density) has been parametrically studied. It is found that the proton maximum energy for the front layers with sub-10 μm thicknesses is independent of the target porosity and density. However, in the relatively thick targets, the nano-porous structure decreases the laser energy absorption and, subsequently, the maximum proton energy compared to the uniform one. The results indicate that by employing UNCPs instead of NPNCPs, at the moderate laser intensity, the maximum proton energy reveals a 23% enhancement. This increment could be explained by rapid self-focusing of the laser pulse and dominant direct laser electron acceleration regime on the well-formed plasma channel in the UNCP layer. However, in the case of NPNCPs, the laser scattering from the plasma structure makes it less intense and more disordered, which influences the efficient laser energy coupling to the electrons.
关键词： proton acceleration,near-critical plasmas,particle-in-cell simulations,ultra-intense laser,laser-plasma interaction
更新于2025-09-23 15:21:01
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Mid-infrared saturated absorption spectroscopy inside a hollow glass waveguide
摘要： We report the saturation spectroscopy of carbon dioxide inside a hollow glass waveguide (GW) using a tunable mid-infrared difference frequency generation (DFG) source. This DFG source was generated in a periodically poled lithium niobate crystal with a tuning range from 3.97 to 4.71 μm. Saturated spectroscopy was performed on the R(60) transition of CO20001 ← 0000 band at 4.2 μm inside a hollow GW of diameter 300 μm and length 1 m. The saturation dip signal was found with a pump power as low as 0.18 mW inside the hollow GW. The linewidth of the dip was determined to be 4.40 MHz.
关键词： Nonlinear optical interaction,Mid-infrared,Saturation spectroscopy,Hollow glass waveguide
更新于2025-09-23 15:21:01
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Vectorial control of the spin-orbit interaction in suspended InAs nanowires
摘要： Semiconductor nanowires featuring strong spin-orbit interactions (SOI), represent a promising platform for a broad range of novel technologies, such as spintronic applications or topological quantum computation. However, experimental studies into the nature and the orientation of the SOI vector in these wires remain limited despite being of upmost importance. Typical devices feature the nanowires placed on top of a substrate which modifies the SOI vector and spoils the intrinsic symmetries of the system. In this work, we report experimental results on suspended InAs nanowires, in which the wire symmetries are fully preserved and clearly visible in transport measurements. Using a vectorial magnet, the non-trivial evolution of weak anti-localization (WAL) is tracked through all 3D space, and both the spin-orbit length lSO and coherence length l? are determined as a function of the magnetic field magnitude and direction. Studying the angular maps of the WAL signal, we demonstrate that the average SOI within the nanowire is isotropic and that our findings are consistent with a semiclassical quasi-1D model of WAL adapted to include the geometrical constraints of the nanostructure. Moreover, by acting on properly designed side gates, we apply an external electric field introducing an additional vectorial Rashba spin-orbit component whose strength can be controlled by external means. These results give important hints on the intrinsic nature of suspended nanowire and can be interesting for the field of spintronics as well as for the manipulation of Majorana bound states in devices based on hybrid semiconductors.
关键词： weak anti-localization,spin-orbit interaction,Rashba effect,indium arsenide,nanowire
更新于2025-09-23 15:21:01
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Tunable topological charge vortex microlaser
摘要： The orbital angular momentum (OAM) intrinsically carried by vortex light beams holds a promise for multidimensional high-capacity data multiplexing, meeting the ever-increasing demands for information. Development of a dynamically tunable OAM light source is a critical step in the realization of OAM modulation and multiplexing. By harnessing the properties of total momentum conservation, spin-orbit interaction, and optical non-Hermitian symmetry breaking, we demonstrate an OAM-tunable vortex microlaser, providing chiral light states of variable topological charges at a single telecommunication wavelength. The scheme of the non–Hermitian-controlled chiral light emission at room temperature can be further scaled up for simultaneous multivortex emissions in a flexible manner. Our work provides a route for the development of the next generation of multidimensional OAM-spin-wavelength division multiplexing technology.
关键词： data multiplexing,orbital angular momentum,chiral light emission,non-Hermitian symmetry breaking,vortex light beams,spin-orbit interaction,microlaser,telecommunication wavelength
更新于2025-09-23 15:21:01