Photodetectors, based on GaAs nanowires (NWs), hold significant promise in the fields of high integration micro- and nano-optoelectronics applications because of their outstanding electronic and optical properties. To date, significant efforts have been directed toward enhancing the performance of photodetectors, aiming for high detectivity and fast response. However, considerable challenges remain in achieving both efficient separation of carriers and enhancing gain capabilities simultaneously. In this work, we report a high-performance GaAs core-shell nanowire photodetector featuring a hybrid-crystallization (HC) Sb2S3 shell that incorporates homogeneous crystalline quantum dots (QDs) within an amorphous matrix. The Sb2S3 shell reconfigures the valence valley and introduces trap states, thereby effectively separating photo-generated carriers spatially while serving as a conduit for minority carriers. The unique hybrid-crystallization shell emerges as a crucial factor in enhancing performance. The core-shell nanowire photodetector presents a high responsivity of 1061.3 A W-1, a detectivity of 1.2 & times; 10(12) cm Hz(0.5) W-1, and an external quantum efficiency (EQE) of 1.63 & times; 10(5)% at 5 V under 808 nm irradiation, surpassing those of conventional GaAs nanowire photodetectors. Moreover, this device demonstrates rapid response characteristics. These findings underscore a unique strategy for designing high-performance nanowire photodetectors through the incorporation of engineered amorphous quantum dots.

Superconducting qubits stand as a pivotal platform for quantum computing, where scalable fabrication is crucial for building complex quantum circuits. Here, we develop a fabrication process for Nb/Al-AlOx/Nb tri-layer Josephson junctions on 4-inch silicon wafers using full-stepper lithography. Utilizing this process, we have produced both transmon and C-shunt flux qubits. The well-behaved I-V characteristics of junction arrays containing up to 1000 junctions highlight the excellent uniformity and scalability of our process. Furthermore, by introducing a RIE pre-etch before BOE treatment to remove most of the SiO2 insulator, we have suppressed dielectric loss and increased the coherence time of the Nb-based transmon qubit by almost 10 times, achieving a quality factor comparable to state-of-the-art Nb-based qubits on sapphire substrates. Given its compatibility with silicon technology, our method paves the way for the integration of multi-qubit processors and the co-fabrication of complex quantum circuits.

In recent years, low-dimensional semiconductors have attracted widespread attention in the field of next-generation broadband infrared photodetectors due to their tunable band structures, strong light-matter interactions, and compatibility with mixed-dimensional integration. Among them, tellurium (Te) and bismuth selenide (Bi2O2Se) have become ideal candidate materials for high-performance detection due to their inherent anisotropy, high carrier mobility, and broad spectral response. Constructing heterojunction photodetectors based on these materials can achieve self-powered operation and suppress dark current. Heterojunction interface engineering and band structure design capabilities are crucial for constructing highperformance Te/Bi2O2Se heterojunction photodetectors. Therefore, we in-situ construct a one-dimensional (1D) Te/two-dimensional (2D) Bi2O2Se heterojunction by a two-step chemical vapor deposition method, which shown a clear interface and type-II band alignment structure. Therefore, the photodetector based on Te/Bi2O2Se heterojunction working in self-driven mode exhibits high performance, showing a high responsivity of-0.89 A & centerdot;W-1 and a fast response time of-29/41 mu s under 1550 nm light irradiation. Further, owing to the optical absorption anisotropy of tellurium, the device exhibited a high polarization ratio of 2.8 and successfully demonstrated polarization optical communication and polarization imaging applications. This work provides new ideas for the in-situ construction strategy of high-quality mixed-dimensional van der Waals heterojunctions and the research on high-performance photodetectors and their applications.

The superlattice long-wavelength infrared focal plane detectors operate at low temperatures. The differences in the thermal expansion coefficients among the various material layers of the detectors can lead to deformation and generate thermal stress, which in turn affects the optoelectrical performance of the detector. This study designed two structural modules to achieve the regulation of stress in the superlattice detectors. The changes in the dark current and spectral response of InAs/GaSb type II superlattice long-wave infrared focal plane detectors under different stress conditions were explored. The research indicates that within the stress range of-10. 7 MPa to 131. 9 MPa, the variation in the opto- electrical performance of the detector is small. The detector was subjected to a temperature shock test, and it demon- strated high reliability. The research results provide guidance for the structural design of InAs/GaSb type II superlattice long-wave infrared focal plane detectors and offer a basis for their performance and reliability assessment.

We demonstrate a mid-infrared superconducting microstrip single-photon detector (SMSPD) based on a 5 nm thick, 0.92-mu m wide, and 50 mu m long NbN microbridge. The detection sensitivity is enhanced via He+ ion irradiation with a high fluence of 1 x 1017 ions/cm2. The SMSPD exhibits saturated internal detection efficiency over a broad spectral range from 400 nm to 5 mu m at 0.32 K, with a minimum timing jitter of 28 ps (at 1064 nm). The detection current scales with photon energy as alpha approximate to-0.5, indicating vortex-assisted hotspot formation as the underlying detection mechanism.

SiCf/SiC composites exhibit advantages such as high-temperature resistance, oxidation resistance and high strength, making them a "star" candidate material in the field of aerospace thermal protection. Under operational conditions, these materials are subjected to prolonged multiple coupled fields such as heat, water and oxygen, exhibiting complex failure mechanisms and damage evolution patterns. This study investigated the integrated oxidation mechanism of the matrix/interface/fiber in Mini-SiCf/BN/SiC composites under cyclic oxidation at 1100 degrees C in a water-oxygen coupled environment by using multi-scale macro/micro characterization techniques. The results showed that during the initial oxidation stage, an amorphous SiO2 glass layer with relatively smooth morphology formed on the material surface. However, with an increase in crystallinity, localized spallation occurred in the oxide layer, causing the surface roughness to initial decrease and subsequent increase. X-ray microscope results showed that numerous micro-defects were generated within the material after cyclic oxidation, and the number of defects increased by orders of magnitude (about 107 fold). Majority of these micro-defects were mainly distributed on the matrix surface, and the oxidation products played a certain filling role in these defects. The tensile strength showed no significant variation before ((328.47 +/- 32.84) MPa) and after ((343.27 +/- 35.71) MPa) cyclic oxidation, indicating continued effectiveness of the synergistic toughening mechanism of "strong matrix-weak interface". These observations indicate that an integrated oxidation protection mechanism involving matrix, interface and fiber exists in the Mini-SiCf/BN/SiC, which is predicated on the filling of defects by SiO2 and borosilicate glass generated by its interface layer and adjacent matrix with fibers in the direction parallel to the fiber axis. Dynamic "outer porous sacrificial layer-middle dense SiO2-inner SiC matrix" is a three-dimensional protective barrier of the matrix in the direction perpendicular to the fiber axis. This dual-protection system substantially alleviates material degradation under cyclic thermal water oxidative conditions.

Twin-field quantum key distribution (TF-QKD) elevates the secure key rate from a linear to a square-root dependence on channel loss while preserving measurement-device-independent security. This protocol is uniquely positioned to enable global-scale quantum networks, even under extreme channel loss. While fiber-based TF-QKD implementations have advanced rapidly since its proposal, free-space realizations have remained elusive due to atmospheric turbulence-induced phase distortions. Here, we report the first experimental demonstration of free-space TF-QKD over 14.2 km urban atmospheric channels, surpassing the effective atmospheric thickness -- a critical threshold for satellite compatibility. We achieve a secret key rate exceeding the repeaterless capacity bound, a milestone for practical quantum communication. Our approach eliminates the need for an auxiliary channel to stabilize a closed interferometer, instead leveraging open-channel time and phase control of optical pulses. This work represents a pivotal advance toward satellite-based global quantum networks, combining high-speed key distribution with inherent resistance to real-world channel fluctuations.

Superconducting quantum interference devices (SQUIDs) based on nanobridge junctions (NBJs) are promising platforms for highly sensitive magnetic detection. The SQUID performance is influenced by the non-sinusoidal current-phase relation (CPR) of NBJs. In this work, we measured the flux modulation of 10 asymmetric Nb SQUIDs based on three-dimensional NBJs, along with the CPR response in each device, which is mainly determined by the junction with the smaller critical current. By studying the CPR parameters (skewness Δθ, critical current Ic1, and effective junction inductance Lj), together with the SQUID modulation characteristics (voltage modulation amplitude ΔIcRn and current modulation ratio ΔIc/2Ic1), we found that as Ic1 increases from 0.6 μA to 6.6 μA and Lj correspondingly decreases from 106 pH to 70 pH, the CPR skewness Δθ increases from 0.2 rad to 1.5 rad. Over this range, ΔIc/2Ic1 decreases from 1.2 to 0.5, while ΔIcRn increases from about 0.06 mV to 0.22 mV. More specifically, ΔIcRn increases while ΔIc/2Ic1 decreases with increasing Ic1, whereas both quantities decrease with increasing Lj. These results reveal a trade-off between intrinsic SQUID response and tolerance to readout noise, suggesting that improved performance can be achieved by engineering NBJs with increased Ic1 and smaller Lj.

Abstract Employing superconducting memory to construct neuromorphic hardware offers a promising route to low-energy and high-speed computation while mitigating the data-transfer bottleneck between superconducting functional modules inherent to the conventional von Neumann architecture. In this work, we develop an in-memory computing architecture based on a superconducting multi-fluxon storage device made of nanoscale JJs. It is capable of implementing fundamental neural network operations, and supports 4 discrete synaptic weight storage and probabilistic weighted computation of inputs, achieving clear classification performance and 100% accuracy on a9-pixell image recognition task. By increasing the discretization levels of synaptic weights, the architecture is expected to handle more complex information-processing tasks, such as recognition of the Modified National Institute of Standard and Technology handwritten digit dataset. These results highlight the potential of superconducting memory devices as scalable and powerful building blocks for emerging computing architectures toward general artificial intelligence.

Perovskite relaxor ferroelectrics have emerged as the leading capacitive energy-storage materials in pulsed-power electronics and integrated energy systems. However, conventional relaxor design strategies encounter a fundamental trade-off, wherein increasing compositional complexity to suppress hysteresis typically weakens local polar strength, thereby hindering the simultaneous realization of ultrahigh recoverable energy density (Wrec) and efficiency (η). Herein, we demonstrate that sublattice-hierarchical local atom clustering provides an effective approach to overcoming this limitation. By combining strong A-site disorder with Mg/Hf-rich nanoregions on B-site sublattices, we embed atomic clusters within a relaxor ferroelectric matrix to stabilize a supercritical relaxor state. Through neutron total scattering techniques and atomic-resolution electron microscopy, we reveal that local atom clusters not only enhance lattice distortion to form ultrafine polar nanodomains but, more importantly, strengthen the local random field to enable strong and highly reversible polarization. As a result, the designed lead-free ceramic achieves an ultrahigh Wrec of 17.03 J cm-3 and an excellent η of 93.5%, resulting in a superior figure of merit up to 262. The fast-discharging capability and robust stability against temperature, frequency, and cycling further evidence its strong application potential. These findings identify local atom clustering as a general and powerful approach for designing high-performance dielectric ceramic capacitors.

ABSTRACT Machine vision, a crucial branch of artificial intelligence and computer vision, enables machines to perceive, analyze, and make decisions based on visual data from images or videos. Its basic process includes collecting environmental information with sensors, extracting features with image processing algorithms, and converting information into executable instructions. Two‐dimensional (2D) ferroelectric materials, due to their characteristics such as a surface without dangling bonds, ultrafast polarization switching, room‐temperature bulk photovoltaic effect, and ultra‐low power consumption, perform well in simulating synapses and retinas, and can achieve multi‐state storage and neuromorphic functions. This review examines the application of 2D ferroelectric materials in machine vision. It introduces several representative materials, analyzes various typical device structures, and highlights key achievements of thesse devices in this field. As an emerging class of materials, 2D ferroelectrics hold promise for integrated sensor‐memory‐computing systems, offering new pathways for the advancement of modern electronics.

To overcome the fiber chromatic dispersion(CD)-induced power fading in intensity modulation direct detection(IM/DD),self-coherent detection is an advanced DD solution enabling optical field recovery without local os-cillators(LOs)for CD compensation.For cost-efficient and high-performance short-reach links,we propose car-rier-extracted self-coherent(CESC)detection,which derives the LO from the incoming signal by employing a narrowband coupled-resonator optical waveguide(CROW)filter.Thus,the signal-to-signal beat interference(SSBI)could be effectively suppressed,enabling complex-valued double-sideband signal retrieval with linear equalization only.In this work,we demonstrate,to our knowledge,the first silicon photonic integrated CESC receiver,achieving 303.8-Gb/s data rate over 50-km standard single-mode fiber using a 62-Gbaud PCS-64QAM signal at a low carrier-to-signal power ratio(CSPR)of 0 dB with only linear equalizers,which is promising for short-reach links in datacenters and access networks.

Tungsten trioxide (WO3) is considered one of the most promising inorganic electrochromic materials due to its low cost, environmental friendliness, and high optical modulation capability. However, during the coloring/bleaching process, WO3 films often suffer from performance degradation caused by ion trapping, resulting in slow response times and poor cycling stability. Herein, a transparent WO3/Nb2O5 heterostructured electrode is designed, where a built-in electric field is formed at the interface due to differences in band alignment and Fermi levels between WO3 and Nb2O5. This internal field acts as a critical driving force for charge transfer and ion migration, thereby enabling a fast and reversible electrochromic response. The prepared WO3/Nb2O5 heterostructure exhibits a high optical contrast (78.4% at 700 nm), fast switching speed (tc/tb = 9.3/10.4 s), and excellent cycling stability (maintaining 97.2% of its initial modulation after 10 000 cycles). Moreover, simulation results indicate that the electrochromic window based on the WO3/Nb2O5 heterostructure demonstrate effective solar radiation regulation and significant energy-saving potential across various global regions. This work provides an effective strategy for the rational design of electrochromic materials and holds great promise for applications in smart windows and intelligent display technologies.

The cryogenic environment offers a promising platform for integrated quantum photonic systems thanks to its low noise characteristics and compatibility with key quantum components, such as superconducting detectors and quantum dots. To harness the full potential of cryogenic integrated quantum photonic circuits, the development of cryogenic adapted on-chip optical filters with exceptional performance is crucial, particularly for efficient extraction of single photon signals from intense pump light in nonlinear processes like spontaneous four-wave mixing. In this work, we demonstrate a cryogenic-compatible Bragg filter, featuring a sinusoidal coherency-broken cascaded architecture for ultrahigh rejection and narrowband. Two subwavelength gratings are deployed to eliminate the residual transverse magnetic mode photons induced by imperfect polarization alignment. Furthermore, a niobium nitride film is deposited on the chip surface as a light absorption layer to suppress background noise caused by scattered photons. The fabricated filter exhibits a rejection ratio of 82 dB at room temperature, and maintains 76 dB at a cryogenic temperature of 2.2 K, with corresponding bandwidths of 0.9 nm and 0.8 nm, respectively. These results confirm the suitability of this filter for the cryogenic working environment, providing crucial support for the cryogenic-compatible integrated quantum photonic circuits.

With the rapid advancement of 2D material-based optoelectronic devices, significant progress is made in the development of all-optical logic devices, synaptic biomimetic devices, and multidimensional detection systems. As entering to the high-speed information era, there is an urgent demand for complex, compact, multifunctional, low-energy, and high-speed intelligent sensing chips. Examining the evolution of current technologies reveals a parallel in the advancement of bipolar response mechanisms-from simple positive and negative responses to more intricate inhibition-promotion dynamics with persistent characteristics. This evolution significantly broadens their applications in biomimetic devices. Moreover, compared to unipolar responses, complex bipolar responses offer greater flexibility in adaptation and a unique one-to-one mapping with high-dimensional information parameters such as polarization, phase, and spectrum, positioning them as promising candidates for breakthroughs in multidimensional detection and resolution. In this review, design strategies are comprehensively explored for various bipolar responses in 2D materials, highlighting their deep applications and progress in advanced fields. It is aimed for this review to provide a broad overview of bi-directional response mechanisms, offering inspiration for designing the next generation of intelligent sensing chips.

In this study, we investigate the impact of substrates with distributed Bragg reflectors (DBRs) on the proximity effect during the fabrication of superconducting nanowire single-photon detectors (SNSPDs) using electron beam lithography. We compare the linewidth compression and line edge roughness of nanowires prepared on three different DBRs substrates. Additionally, we characterize the variations in switching current (Isw) and intrinsic detection efficiency (IDE) at a 2.2-K temperature. The results show that when the substrates are composed of low atomic number materials, such as Si and SiO2, the proximity effect is significantly mitigated. As a consequence, the lithography quality of nanowires is effectively improved, thus enhancing the IDE of SNSPDs. This study is expected to provide new insights into the fabrication of SNSPDs and lay the foundation for the preparation of high-performance and high-uniformity large-area devices.

Thin-film surface acoustic wave (SAW) devices exhibit high quality factors and are promising candidates for quantum transducers, with significant potential for on-chip integration with high-coherence superconducting quantum circuits and optical resonators. However, the experimental demonstration of strong coupling between thin-film SAWs and superconducting qubits in the quantum regime remains a considerable challenge. In this study, we demonstrate strong coupling between a ScAlN thin-film SAW resonator and a high-coherence qubit on the same substrate, where the enhanced qubit coherence was achieved through selective ScAlN etching. Distinct multimode anticrossings are observed in both the qubit and SAW resonator frequency spectra, with extracted coupling strengths closely matching theoretical predictions. Additionally, we investigate qubit decay and the dissipation properties of the SAW resonator in the SAW-qubit hybrid system. Our results confirm the feasibility of integrating thin-film SAW devices with high-coherence superconducting circuits and offer valuable insights for optimizing the performance of such hybrid systems.

Abrikosov vortices trapped in superconducting circuits can reduce their operation margin and, in some cases, even lead to failure. Moats have been introduced to reduce the impact of Abrikosov vortices by providing a favorable location for trapping them at a distance from the circuit. However, the distribution mechanism of vortices near moats driven by applied magnetic fields and currents remains unclear. In this study, we used multiple moats to construct square-shaped areas in the niobium (Nb) thin film and employed magnetic force microscopy to observe the distribution of vortices induced by applied magnetic fields and currents near these areas. The moats effectively prevented vortices from entering the square-shaped area, particularly when the spacing between two moats was <550 nm. Furthermore, we discovered that the edges of moats generated new vortices with polarities opposite to those entering from both the edges of the Nb film under applied current. These vortices attracted each other and annihilated in pairs. These findings provide more insights into designing the layouts of superconducting integrated circuits.

Efficiently distinguishing photon numbers is a crucial yet challenging technology for various quantum information and quantum metrology applications. While superconducting transition edge sensors offer good photon-number-resolving (PNR) capabilities, they are hampered by low detection speed, timing jitter, and complex cooling and readout requirements. In this work, we present a significant advancement toward achieving high-fidelity PNR single-photon detectors by combing high efficiency superconducting nanowire single-photon detector and spatial multiplexing technology. The unique twin-layer configuration of superconducting nanowire atop a dielectric mirror ensures the near-unity detection efficiency. The segmented design, where each section is shunted by a resistor, enables spatial multiplexing, establishing a mapping relationship between pulse amplitude and registered photons. The fabricated detector exhibits impressive performance metrics, including a single-photon system detection efficiency (SDE) of similar to 98% at a dark count rate of 20 cps and photon-number resolution capability up to 32. Further characterization through detector tomography reveals high fidelities for two-, three-, and four-photon events, approximately 87%, 73%, and 40% respectively. Moreover, the detector operates at a high count rate of 41 MHz at 3 dB-SDE, with a low timing jitter of as low as 40 ps. With its near-unity efficiency, high photon-number resolution, low dark count rate, fast detection speed, and superior timing resolution, we expect significant interest in these detectors, promising substantial benefits for weak light detection and optical quantum information applications.

High-quality entangling gates are crucial for scalable quantum information processing.Implementing all-microwave two-qubit gates on fixed-frequency transmons offers advantages in reducing wiring complexity,but the gate performance is often limited due to the residual ZZ interaction and the frequency crowding problem.Here,we introduce a novel scheme that enables a microwave drive-activated CZ gate compatible with the coupler structure to suppress the residual ZZ interaction.The microwave drive is applied to the coupler and the microwave drive frequency remains far detuned from the system's transition frequency to alleviate the frequency crowding problem.We model the gate process analytically and demonstrate a theoretical gate fidelity up to 99.9％numerically.Our scheme is compatible with current coupler-structure-based circuits,and insensitive to microwave crosstalk,showing a possible path for all-microwave quantum operations at scale.