The thermal Casimir effect, arising from fluctuating electromagnetic fields of thermally agitated charges, induces thermosensitive forces and presents a novel approach to detecting nanoscale hot electrons, elusive yet ubiquitous in modern miniaturized transistors. However, detecting thermal Casimir forces at the nanoscale remains extremely challenging due to background forces such as electrostatic force and quantum Casimir force. In this study, we present the first non-contact force measurement of hot electrons based on the thermal Casimir effect. Using an atomic force microscope (AFM) with a dual-resonant tip, we achieve thermosensitive force detection of nonequilibrium hot electrons while effectively suppressing background thermo-insensitive forces, thereby distinguishing them from cold electrons. In silicon nanoconstriction devices, the measured thermal Casimir pressure reaches approximately 3 bar at a separation of 5 nm at an electron temperature of about 10^3 K. Our work introduces a novel methodology for hot electron nanothermometry and provides critical insights into the thermo-mechanical properties of post-Moore nanoelectronics.

Superconducting bolometric detectors offer unrivaled sensitivity across a broad spectral range. However, their multispectral resolving capability is fundamentally constrained by a reliance on bulky external elements such as beam splitters, filters, or spectrometers. To overcome this limitation, we report an on-chip photon-sorting superconducting infrared nanobolometer based on a dual-band metal-insulator-metal metasurface. The device utilizes a nested two-channel Nb nanowire architecture to achieve simultaneous plasmonic infrared harvesting, spectral sorting, and photoelectric conversion within a single structure. At 5.7 K, the bolometer exhibits distinct responsivity peaks at similar to 1025 cm(-1) ( 9.7x10(6) V/W) and similar to 1377 cm(-1) ( 3.7x10(7) V/W), with a photon-sorting efficiency exceeding 70%. This integrated device provides a compact and highly sensitive platform for infrared photodetection, with direct applications in weak-light thermal imaging and precision temperature sensing.

High-sensitivity, bias-selective dual-band infrared detection is essential for two-color absolute thermometry of mid- to long-wavelength infrared sources, including the picowatt-class signal regime relevant to cryogenic near-field thermal measurements. Here, we report a triple-quantum-well charge-sensitive infrared phototransistor in which two spatially isolated floating gates provide electrically separated photoresponse pathways, allowing the 10.1 and 16.4 μm channels to be addressed individually or jointly by gate bias. The cross-hole plasmonic grating supports two geometrically distinguishable resonances with different dominant tuning sensitivities: a period-dominated Rayleigh anomaly–surface plasmon polaritons (SPP) mode and an arm-length-dominated localized shape plasmon–SPP hybrid mode. This partially mode-decoupled response reduces spectral entanglement and enables practical co-design of the two infrared bands. At an optimized well doping of 8.0 × 1017 cm−3, the device delivers an integration responsivity of 6.17 × 105 A W−1 at VSD = 10 mV under a 4.24 pW, 300 K background; the band-resolved photocurrent responsivities at VSD = 120 mV are 1.35 × 103 A W−1 at 10.1 μm and 6.07 × 103 A W−1 at 16.4 μm. Quantum efficiencies of 19.4% (10.1 μm) and 16.0% (16.4 μm) yield specific detectivities of 8.5 × 1011 and 1.1 × 1012 cm Hz1/2 W−1, respectively, with a balanced (∼1:1) dual-band spectral response suitable for two-color pyrometry. The architecture establishes a route to high-gain dual-band mid- to long-wavelength infrared sensing for cryogenic two-color thermometry.

Charge-sensitive infrared phototransistors (CSIPs) based on GaAs/AlGaAs double quantum well structures have emerged as promising detectors for the scattering type scanning near-field optical microscope (SNOM), owing to their exceptional sensitivity in infrared radiation detection. These devices enable real-space mapping of nanoscale thermal phenomena, including thermal electron energy dissipation. However, the performance of CSIP still requires further optimization to detect extremely weak near-field signals, enabling higher temporal and spatial resolution in SNOM. In this work, we have demonstrated a GaAs/AlGaAs CSIP with significantly enhanced optoelectronic performance, achieved through oxygen impurity concentration reduction and implementation of a modulation doping scheme to boost the two-dimensional electron gas mobility in the lower quantum well. The optimized device exhibits a photocurrent of 7.43μA under a source-drain bias of 30 mV at 4.2 K, achieving an exceptional responsivity of 1.34 × 106A W-1at a radiation power of 5.54 pW. Notably, the devices maintain a well-defined peak response wavelength at 11.78μm and remain operational at temperatures up to 50 K. These advancements significantly enhance the detection capability of CSIPs for near-field thermal imaging applications.

The relentless pursuit of smaller, faster nanoelectronics concentrates intense heat at nanometer scales, threatening performance and reliability. Yet directly mapping this heat from nonequilibrium hot electrons has remained elusive. Here we introduce the non-contact force technique that directly images hot-electron temperature distributions in operando devices. Using a bimodal atomic force microscope with sideband modulation, we harness frequency mixing to greatly boost sensitivity to hot-electron forces while suppressing parasitic electrostatic signals. This enables a thermal force microscope that visualizes hot electrons in the nanoconstriction of a silicon channel. Quantitative analysis reveals that thermal-fluctuation-induced force from hot electrons ( Δ T e ~ 700 K ) significantly exceed indirect effects from lattice heating ( Δ T L ~ 3 K ) or permittivity changes. At a 5 nm tip-sample gap, this pressure reaches ~3 bar, sufficient to drive substantial electro-thermo-mechanical effects. These results open a powerful route to probing hot-electron dynamics in working nanodevices and inform electro-thermal co-design strategies for post-Moore nanoelectronics.

High-performance multispectral infrared photodetectors are essential for advanced imaging and sensing technologies. Here, we demonstrate a frequency division multiplexed (FDM) dual-band infrared phototransistor operating at 9.9 and 14.9 mu m through a single source-drain channel. The device incorporates a double GaAs/AlGaAs quantum well (QW) structure, where two QWs of different thicknesses (7 and 11 nm) serve as charge-sensitive intersubband absorbers. Optical excitation at each wavelength induces opposite charge polarities on a floating gate, which are selectively demodulated by periodic resetting with distinct frequencies. This FDM operation enables simultaneous, independent readout of both spectral bands. Finally, we demonstrate absolute temperature sensing using the dual-band response, highlighting the device's potential for compact multispectral infrared sensing and imaging systems.

Localized hotspots arising from non-uniform energy dissipation fundamentally limit the performance of nanoscale electronic devices. Thermoelectric (TE) cooling provides a direct means to mitigate this challenge by coupling charge and heat transport. Conventional TE theory, however, typically assumes the Seebeck response as scalar, such that heat flow remains collinear with electrical current and cooling is restricted to the transport direction. Here, we observe a pronounced transverse TE response without external magnetic fields and demonstrate absolute cooling at room temperature in the anisotropic van der Waals semimetals Td-WTe2 and TaIrTe4. Control measurements on isotropic Bi2Te3 devices show that the effect originates from the intrinsic in-plane anisotropy of the Seebeck tensor. By exploiting this tensorial response in asymmetric monolithic TE legs, we achieve local TE cooling that surpasses Joule heating (ΔT_TE-cold≥ΔT_J) in the region of maximal dissipation, driving the hotspot lattice temperature below ambient, with maximum net cooling values of approximately -60 mK in WTe2 and -100 mK in TaIrTe4. These results establish anisotropic thermoelectricity as a zero-field route to directional heat-flow control in solids and suggest a general strategy for site-specific cooling in on-chip devices.

In advanced microelectronics, heat originates within nanoscale transistor channels, where field-driven electrons accelerate and scatter before equilibrating with the lattice—forming highly localized hotspots. Heat then dissipates through mechanisms ranging from angstrom-scale phonon interactions to packaging-level conduction. Despite decades of efforts in chip thermal management, such as packaging-level cooling, the role of hot electrons at the root of nanoscale hotspot formation has remained insufficiently recognized. This perspective highlights recent advances in passive imaging of hot-electron dynamics in hotspot regions, revealing strong electron–lattice nonequilibrium (Te ∼ 103 K, far exceeding TL ∼ 300 K) and spatial decoupling that go beyond the classical Joule heating paradigm at the macroscale. This calls for a shift toward electron-focused thermal design at the individual transistor level. We outline emerging strategies to either suppress nanoheat generation (e.g., ΔTe ∼−50 K by evaporative cooling) or harness hot electrons to overcome thermal-equilibrium Boltzmann limits in post-Moore nanoelectronics.

Miniaturized reconstructive spectrometers are of critical significance as they enable the acquisition of incident spectra for analysis with a compact footprint by utilizing reconstruction techniques. However, the typical miniaturized reconstructive spectrometers are not readily adaptable to large‐scale production due to their lack of compatibility with complementary metal‐oxide‐semiconductor (CMOS) manufacturing. Here a silicon nanomembrane miniaturized spectrometer with wedge‐shaped structures based on the silicon‐on‐insulator wafer is demonstrated. The fabrication technique is straightforward and CMOS‐compatible, suggesting the potential of wafer‐scale manufacturing. The atomic‐level thickness variation of the structure enables our spectrometer to theoretically achieve a high level of integration. The spectrometer achieves a resolution of ≈1.85 nm and a spectral wavelength accuracy of up to ≈0.1 nm in a broad bandwidth (from 400 to 1 000 nm) with micron‐scale footprint. Furthermore, the spectrometer's spectrum imaging capabilities are also showcased. This research will introduce a feasible paradigm for miniaturized reconstructive spectrometers with a high performance and the potential for commercial application.

Epitaxial strain is an effective way to control thermoelectricity of a thin film system. In this work, we investigate strain-dependent thermoelectricity of [(SrTiO3)3/(SrTi0.8Nb0.2O3)3]10 superlattices grown on different substrates, including -0.96% on (LaAlO3)0.3(SrAl0.5Ta0.5O3)0.7(001) (LSAT), 0% on SrTiO3(001) (STO), +0.99% on DyScO3(110) (DSO) and +1.64% on GdScO3(110) (GSO), respectively. Our results show that the highest room-temperature thermoelectricity is achieved when the STO-based superlattice is grown on the DSO substrate with +0.99% tensile strain. This is attributed to the high permittivity and low dielectric loss arising from the ferroelectric domain and electron-phonon coupling, which boost the power factor (PF) to 10.5 mW & sdot;m-1 & sdot;K-2 at 300 K.

Bipolar photoresponse - where photocurrent polarity reverses with excitation wavelength, gate voltage, or other conditions - is essential for optical logic, neuromorphic computing, and imaging. Unlike unipolar responses, bipolar behavior enables direct binary encoding and enhanced photodetection contrast. However, in conventional photoconductive or photovoltaic systems, the simultaneous and opposite-directional transport of electrons and holes often suppresses polarity switching. Recent self-powered Shockley-Ramo (SR) photoresponse in gapless materials also show only unipolar signals due to strong, irreversible electron-hole asymmetry. Here, we demonstrate for the first-time bipolar SR photoresponse in GaAs nanoconstriction devices by exploiting reversible electron-hole asymmetry. The longer carrier lifetimes in GaAs enable sub-diffusion-length control of carrier dynamics through geometry. By tuning photocarrier dynamics near the nanoconstriction for both majority electrons and minority holes, we modulate the SR response to exhibit dual polarities. At low excitation, photoelectrons dominate; as excitation increases, intervalley scattering populates higher-energy L-valleys, reducing electron contribution and leading to polarity reversal driven by the growing dominance of photoexcited holes. These results, supported by SR theory, show that nanoscale geometric engineering, together with the reversible electron-hole asymmetry, enables self-powered bipolar photocurrent responses, offering new routes toward advanced optoelectronic devices.

The recently emerged remote epitaxy technique, utilizing 2D materials (mostly graphene) as interlayers between the epilayer and the substrate, enables the exfoliation of crystalline nanomembranes from the substrate, expanding the range of potential device applications. However, remote epitaxy has been so far applied to a limited range of material systems, owing to the need of stringent growth conditions to avoid graphene damaging, and has therefore remained challenging for the synthesis of oxide nanomembranes. Here, we demonstrate the remote epitaxial growth of an oxide nanomembrane (vanadium dioxide, VO2) with a sub-nanometer thick amorphous interlayer, which can withstand potential sputtering-induced damage and oxidation. By removing the amorphous interlayer, a 4-inch wafer-scale freestanding VO2 nanomembrane can be obtained, exhibiting intact crystalline structure and physical properties. In addition, multi-shaped freestanding infrared bolometers are fabricated based on the epitaxial VO2 nanomembranes, showing high detectivity and low current noise. Our strategy provides a promising way to explore various freestanding heteroepitaxial oxide materials for future large-scale integrated circuits and functional devices.

Hafnium zirconium oxide with antiferroelectric polarizations holds great promise for emerging applications such as neuromorphic computing, energy-efficient storage, and nonvolatile memory, owing to its tunable phase transitions, fast switching speed, improved endurance, and excellent compatibility with silicon-based processes. In practical memory applications, however, the moderate residual polarizations of antiferroelectric hafnium zirconium oxide films pose greater challenges for nondestructive readout than their ferroelectric counterparts, particularly when relying solely on electrical pulses applied via metal electrodes. Here, we introduce graphite nanosheets as photoactive top electrodes for Hf0.1Zr0.9O2-based nonvolatile memories, enabling nondestructive optical readout through the photo-pyroelectric effect. The optothermally active van der Waals graphite nanosheet top electrode triggers nonpolar-to-polar state transition, thereby inducing a pyroelectric response in the Hf0.1Zr0.9O2 layer. This mechanism enables self-powered and nondestructive photo-pyroelectric sensing capabilities, as well as voltage-programmable in-memory logic functionalities-circumventing the destructive readout issues faced by traditional hafnium-based ferroelectrics. Our work paves the way for hafnium-zirconium-oxide-based, photonic-compatible memory architectures for post-Moore electronics.

Silicon is one of the most promising anode materials for next-generation high-energy-density lithium-ion batteries (LIBs), but it suffers from low conductivity and huge volume variation during lithiation/delithiation. In this work, graphite/silicon/graphite hybrid anodes with unique multilayered structures, called SG/Si/SG and SG/(Si/SG)5, are assembled on copper collectors using magnetron sputtering combined with a coating process. This strategy utilizes the graphite layer to alleviate the volume change of Si and prevent direct contacts of Si with both a current collector and an electrolyte to protect the falling off of the active material from the current collector and to inhibit side reactions. The as-fabricated SG/Si/SG anode has an initial lithiation capacity of 589.4 mAh g-1 with an initial Coulombic efficiency (ICE) of 86.5%. After 300 cycles at 1C, it maintains a specific capacity of 381.8 mAh g-1, with a remarkable capacity retention of 102.3%. Furthermore, under a high loading of ∼7.4 mg cm-2, the SG/(Si/SG)5 anode exhibits an initial areal capacity of 3.433 mAh cm-2 (specific capacity of 463.9 mAh g-1) and an ICE of 89.9%. After 100 cycles at 0.1C, it maintains an areal capacity of 2.024 mAh cm-2 (specific capacity of 290.2 mAh g-1), corresponding to a capacity retention of 67.8%. The multilayered carbon-silicon anode, with SG/(Si/SG)n configuration, should be practically useful for high-energy-density LIBs manufacture.

AbstractFerroelectric semiconductors have the advantages of switchable polarization ferroelectric field regulation and semiconductor transport characteristics, which are highly promising in ferroelectric transistors and nonvolatile memory. However, it is difficult to prepare a Sn-based perovskite film with both robust ferroelectric and semiconductor properties. Here, by doping with 2-methylbenzimidazole, Sn-based perovskite [93.3 mol% (FA0.86Cs0.14)SnI3 and 6.7 mol% PEA2SnI4] semiconductor films are transformed into ferroelectric semiconductor films, owing to molecular reconfiguration. The reconfigured ferroelectric semiconductors exhibit a high remanent polarization (Pr) of 23.2 μC/cm2. The emergence of ferroelectricity can be ascribed to the hydrogen bond enhancement after imidazole molecular doping, and then the spatial symmetry breaks causing the positive and negative charge centers to become non-coincident. Remarkably, the transistors based on perovskite ferroelectric semiconductors have a low subthreshold swing of 67 mv/dec, which further substantiates the superiority of introducing ferroelectricity. This work has developed a method to realize Sn-based ferroelectric semiconductor films for electronic device applications.

Coherent control of magnon excitations is crucial for their potential device application. The integration of the exceptional point in a magnon-photon hybrid system is shown to offer fast, coherent and topologically robust control of magnon-polariton states.

Miniaturized reconstructive spectrometers play a pivotal role in on-chip and portable devices, offering high-resolution spectral measurement through precalibrated spectral responses and AI–driven reconstruction. However, two key challenges persist for practical applications: artificial intervention in algorithm parameters and compatibility with complementary metal-oxide-semiconductor (CMOS) manufacturing. We present a cutting-edge miniaturized reconstructive spectrometer that incorporates a self-adaptive algorithm referenced with Fabry–Perot resonators, delivering precise spectral tests across the visible range. The spectrometers are fabricated with CMOS technology at the wafer scale, achieving a resolution of ~2.5 nm, an average wavelength deviation of ~0.27 nm, and a resolution-to-bandwidth ratio of ~0.46%. Our approach provides a path toward versatile and robust reconstructive miniaturized spectrometers and facilitates their commercialization.

The topology of the photonic bath shows excellent potential to engineer the intriguing interaction properties between light and matter. Here, we study the dielectric resonator array with a zigzag geometry, an analogy of the Su-Schrieffer-Heeger model equipped with peculiar freedom to manipulate the nearest-neighbor coupling strength by the internal interaction. A staggered coupling strength of s-type pillar modes is experimentally achieved via the photonic spin-orbit coupling by employing the zigzag dielectric resonator chain. As a result, we observe that the robust edge states of the zigzag chains manifest themselves with linear polarization for an even number of dielectric resonators but elliptical polarization for an odd number. In addition, by coupling magnons to the topological waveguide, we observe resonant magnon-magnon-edge-state coupling, whose coupling strength is topologically protected. More broadly, our work shows that topological waveguide-QED systems may provide the potential for synthesis and study of many-body states with attractive long-range interaction.

AbstractOptical sensors with in-cell logic and memory capabilities offer new horizons in realizing machine vision beyond von Neumann architectures and have been attempted with two-dimensional materials, memristive oxides, phase-changing materials etc. Noting the unparalleled performance of superconductors with both quantum-limited optical sensitivities and ultra-wide spectrum coverage, here we report a superconducting memlogic long-wave infrared sensor based on the bistability in hysteretic superconductor-normal phase transition. Driven cooperatively by electrical and optical pulses, the device offers deterministic in-sensor switching between resistive and superconducting (hence dissipationless) states with persistence > 105 s. This results in a resilient reconfigurable memlogic system applicable for, e.g., encrypted communications. Besides, a high infrared sensitivity at 12.2 μm is achieved through its in-situ metamaterial perfect absorber design. Our work opens the avenue to realize all-in-one superconducting memlogic sensors, surpassing biological retina capabilities in both sensitivity and wavelength, and presents a groundbreaking opportunity to integrate visional perception capabilities into superconductor-based intelligent quantum machines.

Graphene is a promising candidate for the thermal management of downscaled microelectronic devices owing to its exceptional electrical and thermal properties. Nevertheless, a comprehensive understanding of the intricate electrical and thermal interconversions at a nanoscale, particularly in field-effect transistors with prevalent gate operations, remains elusive. In this study, nanothermometric imaging is used to examine a current-carrying monolayer graphene channel sandwiched between hexagonal boron nitride dielectrics. It is revealed for the first time that beyond the expected Joule heating, the thermoelectric Peltier effect actively plays a significant role in generating hotspots beneath the gated region. With gate-controlled charge redistribution and a shift in the Dirac point position, an unprecedented systematic evolution of thermoelectric hotspots, underscoring their remarkable tenability is demonstrated. This study reveals the field-effect Peltier contribution in a single graphene-material channel of transistors, offering valuable insights into field-effect thermoelectrics and future on-chip energy management.