Atomic-like emitters in the solid state serve as important resources in the advancement of future quantum networks. In particular, intra-4f optical transitions of rare earth ions exhibit excellent coherence properties thanks to the shielding effect of outer electrons. Still, the presence of various dephasing channels in solid state hosts introduces additional decoherence beyond the radiative decay

Two-dimensional (2D) materials offer great prospects in room temperature (RT) gas sensors with minimum power consumption, compared to conventional metal oxide semiconductor sensors that require high temperature operation. In this work, we prepared violet phosphorus (VP) nanosheets by optimized liquid-phase exfoliation in various solvents. A highly sensitive gas sensor has been fabricated by using the

Vacancy related defects play a crucial role in optoelectronic properties and carrier transport for photovoltaic materials, especially for its structural evolution becoming non-radiative defects induced by strain. Thus far, the evolution phenomena of vacancy defects in halide perovskite triggered by energy or strain have not been systematically investigated. Herein, we study the change in defect levels

Field-effect transistors based on semiconductor integration technology have come to a bottleneck, while electric field control of magnetism has great potential for applications in next-generation magnetic memory and calculators based on electron spins. Magnetic properties manipulation from a mechanism of ion migration driven by an electric field has the advantages of low energy consumption, nonvolatility

Amplification of weak ultraviolet signals has always been a challenging issue to design and fabricate high-performance ultraviolet photodetectors. Here, we observe a distinctive microplasma breakdown behavior in AlGaN-based ultraviolet avalanche photodiodes with artificial mesa architecture. At 107 V breakdown voltage, the photocurrent increases sharply whereas dark current intriguingly remains at

Bound states in the continuum (BICs) of plasmonic systems offer a powerful method for enhancing light–matter interaction at the nanoscale. The recent emergence of flatband quasi-BICs has alleviated the limitation of the incident angle of the excitation light on generating high-quality-factor (high-Q-factor) resonances, which makes it feasible to produce substantial near-field enhancement by focused

Memcapacitor devices based on ferroelectric material have attracted attention recently in application of neuromorphic computing due to lower static power relative to memristors. They have been used for establishing fully connected neural networks but not yet for recurrent neural networks (RNNs), which owns the advantage in temporal signal processing. As an improved network architecture for RNNs, reservoir

Most of the existing memristors are complicated to prepare, which is not conducive to actual applications. In this paper, a Zn/ZnSO4/Pt (ZSP) memristor with a simple preparation method is fabricated. The I–V characteristics show good switching characteristics and a stable SET/RESET process. By modulating the weight (current of the memristor) continuously, the ZSP memristor simulates typical synaptic

Ferroelectric polymers with high flexibility and inherent piezo- and pyro-electric properties have gained tremendous importance for next-generation wearable electronics. In this context, we investigate the intrinsic polarity mediated work function modulation in α-, γ-, and β-crystalline phases of a ferroelectric polymer, namely, polyvinylidene fluoride. A wide range of surface potentials (i.e., −5

The 1T′ structural phase of monolayer transition metal dichalcogenides MX2 (M = Mo, W; X = S, Se, Te) has attracted broad interest because of an exotic quantum spin Hall insulator state. Among them, the investigation on the electronic structures of the 1T′-WS2 monolayer is still lacking due to the difficulty in obtaining the 1T′-WS2 as a metastable phase. Here, we report the growth of 1T′ phase WS2

As one of the most important members of the two-dimensional (2D) chalcogenide family, MoS2 plays a fundamental role in the development of 2D electronic and optoelectronic designs. However, MoS2-based optoelectronic devices are hindered by their weak light–matter interactions, which make it challenging to achieve excellent device performance in photoelectronic memory applications. Here, we developed

Internet of Things sensor nodes, which integrate information acquisition, processing, exchange, and execution modules, have widely been used for unattended industrial production, environmental monitoring, and other fields. However, limited battery power constrains the lifespan of the sensor nodes. In this paper, we propose a near-zero-power infrared relay consists of microfluidic switches and a metamaterial

Photonic computing has the potential to significantly improve energy efficiency and data processing speed beyond that of von Neumann architecture. Although various optical processing techniques have been developed during recent two decades, the photonic manipulation is still a big challenging due to the bosonic nature of photons. Herein, we propose a ferroelectric field-controlled photonic computing

Antiferromagnets exhibit ultrafast magnetization precession, which has the potential to enable the development of terahertz spin torque nano-oscillators. By utilizing perpendicularly magnetized magnetic nanopillars with a synthetic antiferromagnetic (SAF) free layer, we have demonstrated through theoretical and numerical analysis that stable out-of-plane precession states can be achieved by applying

A deep-ultraviolet Al0.6Ga0.4N p–i–n avalanche photodiode (APD) structure was grown on a (0001) AlN bulk substrate by metalorganic chemical vapor deposition. The wafer was fabricated into 20 μm diameter mesa APD devices both with and without ion-implantation with nitrogen ions on the periphery of the p-type region of the diode mesa and tested. The dark current density vs bias, photoresponse, and the

Binary α-Ga2O3 and ternary α-(AlxGa1−x)2O3 thin films with x = 0.29 and 0.54 were deposited on a-plane Al2O3 substrates via plasma-assisted molecular beam epitaxy. The strain relaxation dynamics along three orthogonal crystal directions was investigated ex situ and in situ by synchrotron-based high-resolution x-ray diffraction. A pronounced in-plane anisotropy was observed as strain is preferably built

Materials displaying resistive switching have emerged as promising candidates for implementation as components for neuromorphic computing. Under an applied electric field, certain resistive switching materials undergo an insulator-to-metal transition through the formation of a percolating filament, resulting in large resistance changes. The location and shape of these filaments are strongly influenced

We provide a theoretical analysis of the possibility of using circularly polarized radiation to switch between two different quantum states of a superconducting nanoring subjected to the half quantum flux. Numerical modeling, performed in the framework of the time-dependent Ginzburg–Landau equation, reveals the condition for on-demand switching between current-carrying states with different helicities

Tensegrity metamaterials are a type of artificial materials that can exploit the tunable nonlinear mechanical behavior of the constituent tensegrity units. Here, we present reduced-order analytical models describing the prestrain-induced bistable effect of two particular tensegrity units. Closed-form expressions of the critical prestrain at which a unit transitions into a bistable regime are derived

GdCo films have been widely used in spintronic applications, owing largely to their tunable degree of ferrimagnetic compensation. However, all key properties likewise depend on the alloy composition, and a systematic study of the interdependent spintronic properties with composition has not been reported. Here, we report the compositional dependence of key spintronic properties, including anisotropy

Spintronic terahertz (THz) emitters have been intensively explored as next-generation sources of THz waves due to their low-cost, nanometer thickness, and broadband spectra. Growing research works are focusing on how to improve the THz emission efficiency, mainly by using a larger spin-Hall angle heavy metal. Currently, the highest intensity spintronic THz emission was based on a CoFeB/Pt heterostructure

Onsite gain-loss-induced topological braiding principle of non-Hermitian energy bands is theoretically formulated in multiband lattice models with Hermitian hopping amplitudes. Braid phase transition occurs when the gain-loss parameter is tuned across exceptional point degeneracy. Laboratory realizable effective-Hamiltonians are proposed to realize braid groups B2 and B3 of two and three bands, respectively

In this work, a wavefront division interferometry method for determining the topological charge (l) of vortex beams (VB) is proposed and utilized for the detection of beam displacement. The method uses Fresnel biprism as a single element to determine vortex charge for up to l = ±10. Additionally, the interference pattern configuration is utilized to detect beam displacement in orthogonal directions

Mn4N thin films meet the requirements for efficient current-driven magnetic domain wall motion, such as perpendicular magnetic anisotropy and small magnetization. To demonstrate efficient field-free spin–orbit torque (SOT)-driven domain wall motion, the thickness of the Mn4N layer must be reduced. In this study, we focus on the fabrication of Mn4N ultrathin films on SrTiO3(001) substrates and demonstrate

Drop impact on superhydrophobic surfaces has gained great attention because of its physics and application in water repellency, drag reduction, and anti-icing. Spreading lengths and the contact time are the crucial parameters determining the extend of drop–surface interaction and effective heat transfer between the two and are, hence, trivial to many engineering applications. Post-collisional dynamics

We experimentally demonstrate the formation of a superradiant optical mode in the room-temperature reflection spectra from a resonant Bragg structure composed of 30 equidistant GaN quantum wells separated by (Al,Ga)N barriers. The mode arises when the condition of the Bragg diffraction is fulfilled at the wavelength corresponding to the energy of the quasi-two-dimensional excitons in the quantum wells

We report variable in-plane fourfold magnetic anisotropy in epitaxial exchange-biased Fe/IrMn bilayers with different layer thicknesses. The fourfold magnetic anisotropy of the bilayers continuously decreases and even appears negative as the thickness of the Fe layer decreases, indicating a change in the easy axes from Fe 100 to Fe 110, which can be interpreted by the competition between the intrinsic

This Letter investigates low frequency 1/f noise in an hBN encapsulated graphene device in a dual gated geometry. The noise study is performed as a function of top gate carrier density (nTG) at different back gate density (nBG). The noise at low nBG is found to be independent of top gate carrier density. With increasing nBG, noise value increases, and a noise peak is observed near charge inhomogeneity

Antimonide semiconductor laser diodes with high brightness are ideal light sources for a variety of applications. However, the traditional structure of broad-area (BA) lasers with high-power output is normally accompanied by a multi-lobed far field profile and large lateral divergence. In this paper, we put up an on-chip microstructure for mode filtering. The excellent mode control capability is doubly

In recent decades, particle characterization has been one of the most widely used achievements. The article presents a method to simplify the setup using unsupervised machine learning techniques, such as K-means, K-medoids, and Hierarchical clustering. Utilizing these three methods together, our approach can accurately measure particle diameter with a precision of 0.1 μm and a refractive index of 0

MoSH is a representative example of a Janus two-dimensional monolayered system consisting of a molybdenum atomic layer sandwiched between sulfur and hydrogen atomic layers. Extensive experimental and theoretical efforts have suggested the great promise of the MoSH material, but the validity of the MoSH model (with a Mo–S–H ratio of 1:1:1) remains uncertain. While various experiments have established

Advanced functional fibers, which can endow common textiles with specific functionalities by traditional weaving processes without losing their basic features, including flexibility, breathability, and wash ability, are desired in flexible and wearable devices. However, the performance of piezoelectric wire sensors in previous studies has been unsatisfactory, especially in harsh environments. This

We report on photoluminescence emission in copper iodide bulk single crystals induced by two- and three-photon absorption around 1.525 eV. These non-linear optical processes are investigated utilizing density-dependent, steady-state, as well as time-resolved photoluminescence spectroscopy as a function of the excitation energy. Using an excitation energy that corresponds to half of the bandgap energy

Perpendicular exchange bias (PEB) is an essential effect of antiferromagnetic materials. It has the advantages over the in-plane exchange bias in application of magnetic random access memory (MRAM) technology, particularly in terms of higher packing density. The influence of the strain effect on PEB of Ta/Pt/Co/Ir20Mn80/Pt multilayers deposited on the piezoelectric substrate is studied in this work

Rare earth (RE):transition metal (TM) ferrimagnetic alloys continue to attract significant attention for spintronics. This work focuses on the elemental distribution of RE and TM elements throughout the thickness of nominally uniform films and the resulting spatial variations of the magnetization within these layers. Samples of CoFe alloyed with Gd were studied using secondary ion mass spectroscopy

We attempted to grow (10–13) semi-polar GaN on graphene to confirm the possibility of a remote epitaxy of semi-polar GaN. Single crystalline (10–13) GaN was obtained on an optimized template using optimized growth conditions. However, (10–13), (0002), and other GaN orientations were found under the same growth conditions on a graphene-coated template. Scanning transmission electron microscopy and energy-dispersive

We report on the realization of all-optical planar microlensing for exciton–polariton condensates in semiconductor microcavities. We utilize spatial light modulators to structure a nonresonant pumping beam into a plano–concave lens-shape focused onto the microcavity plane. When pumped above condensation threshold, the system effectively becomes a directional polariton antenna, generating an intense

This Letter presents oriented growth and switching of thin (∼30 nm) co-sputtered ferroelectric (FE) aluminum scandium nitride (AlScN) films directly on degenerately doped 4H silicon carbide (SiC) wafers. We fabricate and test metal ferroelectric semiconductor capacitors, comprising of Al/Al0.68Sc0.32N/4H-SiC. Our devices exhibit asymmetric coercive electric field values of −5.55/+12.05 MV cm−1 at 100

We report an easy-to-make, resonance-based mechanism to realize negative rotational inertia. The device consists of three parts: a heavy inner core, a lightweight outer shell, and rubber connections between the core and shell. We theoretically predict and experimentally observe the negative rotational inertia in the range of 100–230 Hz. The experimental values are obtained via measurements of vibrational

Transition metal dichalcogenides (TMDCs), such as semiconducting WSe2, are typically interfaced with a high-quality dielectric layer in device applications. The unreactive basal plane of TMDCs makes the standard technique for deposition of dielectric oxides, atomic layer deposition (ALD), challenging on TMDC surfaces. In this work, we make use of atmospheric ultraviolet–ozone (UV-O3) exposure of WSe2

Refractive index (RI) of polymers plays a crucial role in the design of optoelectronic devices, including displays and image sensors. We have developed a framework for (1) high-throughput computation of RI values for computationally synthesized amorphous polymer structures based on a generalized polarizable reactive force-field (ReaxPQ+) model, which is orders-of-magnitude faster than quantum-mechanical

In this study, we identify the killer defect responsible for the reverse leakage in the halide vapor phase epitaxial (011) β-Ga2O3 Schottky barrier diode via ultrahigh sensitive emission microscopy, synchrotron x-ray topography, and scanning transmission electron microscopy. A polycrystalline defect was found to be causing a leakage current of −5.1 μA at a reverse bias of −50 V. They were distributed

The detection capability of GaN-based nano-diodes is measured up to 110 GHz in two configuration schemes: voltage and current responsivity. The ratio between both figures of merit allows one to extract the AC resistance of the diode, showing a very flat value in all the frequency spans. An optimization on the geometrical parameters is performed, finding that the narrower the channel, the higher the

In this Letter, the phase profile of the self-rotating beam is modified by introducing the radial shift factor c and the azimuthal shift factor θ0. The effect of the radial shift factor c on the corresponding intensity distribution is discussed. The results demonstrate that the focal-field intensity patterns of the modified self-rotating beams with different radial shift factors moved away from the

Fear neural circuits can recognize precisely threatening stimuli and enable the early-warning for the individual in the real world. In this regard, implementation of fear neural circuits functions by neuromorphic devices could potentially improve the intelligent adaptability and cognition of humanoid robots. Here, an artificial fear neural circuit is proposed, which consists of a noise triboelectric

Integration of the emerging layered materials with the existing CMOS platform is a promising solution to enhance the performance and functionalities of the future CMOS based integrated circuits. In this direction, we have experimentally studied the suitability of the layered semimetals, namely, Td-WTe2, 1T′-MoTe2, 1T-PtTe2, and 1T-PtSe2, as an electrode with two most commonly used semiconductors, i

We demonstrate the use of a low-cost liquid-crystal-based wavelength-tunable filter and CMOS video camera to add hyperspectral imaging capabilities to a probe station equipped with a simple optical microscope. The resultant setup is used to rapidly resolve the spectral and spatial variations in electroluminescence typically observed for InxGa1−xN/GaN light-emitting diodes. Applying standard statistical

Various techniques have been applied to visualize superconducting vortices, providing clues to their electromagnetic response. Here, we present a wide-field, quantitative imaging of the stray field of the vortices in a superconducting thin film using perfectly aligned diamond quantum sensors. Our analysis, which mitigates the influence of the sensor inhomogeneities, visualizes the magnetic flux of

In digital holography, extracting the +1-order spectrum accurately and making full utilization of the spatial bandwidth of the CCD sensor are essential for high-resolution and artifacts-free quantitative phase imaging. In this paper, using the light intensity symmetry of the Gaussian laser beam, we delicately eliminate the zero-order spectrum by means of subtraction of two off-axis hologram spectra

Motivated by recent experimental results, we calculate from first principles the lifetime of low-energy quasiparticles in bilayer graphene (BLG). We take into account the scattering rate arising from electron–electron interactions within the GW approximation for the electron self-energy and consider several p-type doping levels ranging from 0 to ρ≈2.4×1012 holes/cm2. In the undoped case, we find that

A noninvasive method was developed to measure the electrical potential in an atmospheric pressure plasma jet. The spatiotemporal evolution of electrical potential was measured by a wire electrode in experiment and simulated by a two-dimensional self-consistent numerical model, which demonstrates that the electrical potential along with the traveling ionization wave outside the discharge tube in ambient

We propose a strain relaxed template (SRT), which consists of an InGaN decomposition layer (DL) and GaN protecting layers grown at three different temperatures as decomposition stop layers (DSLs), to enhance the indium incorporation in quantum wells. The high-temperature growth of the DSL decomposed the InGaN DL and created voids inside to release the strain of the as-grown templates. Although the

Optical control of the exchange bias field in IrMn/[Co/Pt]N heterostructures has been recently demonstrated. We show that this phenomenon can be used to create specific nucleation areas and even decide the preferential direction of propagation of the domain wall inside these preferred areas of nucleation. Using different features of a femtosecond laser, such as the helicity, fluence, and number of

Achieving spin current switching functionality is crucial for the development next-generation low power information storage. In this study, the spin reorientation and temperature dependence of spin Hall angle θSH in the Permalloy (Py)/Pd bilayer were investigated by using ferromagnetic resonance, spin pumping, inverse spin Hall effect, and quantum interference transport. The uniaxial ferromagnetic

We present an electric power meter that capitalizes on the interaction of electrothermal strain and mechanical vibration in a micro-electro-mechanical systems (MEMS) beam undergoing the antisymmetric mode of vibration. This is achieved by using a resonant bridge driven with an electrothermal modulation technique. The change in electrical power is monitored through the alteration in the mechanical stiffness

Ferroelectric heterostructures hold great promise for developing multifunctional memristors and optoelectronic devices. In this study, we report a ferroelectrically modulated photoresponse and optically modulated electroresistance behaviors in the Pt/PbZr0.2Ti0.8O3(PZT)/Nb-doped SrTiO3 (NSTO) heterostructure. The short-circuit photocurrent rises from 28 nA (after poling at +5 V) to 345 nA (after poling

Cerium-substituted yttrium iron garnet (Ce:YIG, Ce0.9Y2.1Fe5O12) was epitaxially grown on a (111)-oriented yttrium aluminum garnet (YAG) substrate using radio frequency ion beam sputtering. Magnetic hysteresis loops, transmissivity spectra, and magnetooptical (MO) responses, including Faraday rotation and Faraday ellipticity, were measured. The structural properties of the grown Ce:YIG were characterized

Nanoscale spontaneous light sources are promising alternatives to lasers for high-speed optical communications and interconnections through energy-efficient integrated circuits. Yet, developing the spontaneous light sources faster than lasers is hampered by the detection means (e.g., time-resolved fluorescence spectroscopy). Here, by coupling monolayer WSe2 to individual plasmonic nanocavities, we

Incorporating color centers in diamond with mature integrated photonics using hybrid integration techniques such as transfer printing provides a promising route toward scalable quantum applications. However, single-crystal diamond nanostructures fabricated using current etching technologies have triangular bottoms that are unsuitable for conventional pick-and-place integration. Herein, we present an

Lithium metal is considered as a highly desirable anode for high-energy and safe quasi-solid-state batteries. Nevertheless, the terrible wettability of molten lithium does not permit it to spread out on the lithiophobic current collectors, limiting their practical applications. Herein, we report an ultrathin lithium–molybdenum (Li–Mo) composite anode to settle this hurdle by reacting molten Li with