Physics

Abstract The evolution of electrochromic materials and technologies has opened innovative avenues for smart devices. However, their civilian adoption remains constrained by high material costs and energy-intensive fabrication processes. Recent research has shifted toward integrated electrochromic systems that combine energy storage with visualization capabilities. Among these, electrochromic supercapacitors (ECSCs) suffer from relatively low energy density, constraining their storage capacity, whereas electrochromic zinc-ion batteries (ECZIBs) demonstrate superior energy density, making them more promising for smart energy storage applications. This review systematically examines the fundamental structure, key performance parameters, and essential materials of ECZIBs, with particular focus on recent progress in the design of cathode, anode, and electrolyte materials. We summarize the major bottlenecks currently impeding performance enhancement and practical deployment, discuss potential strategies to overcome these challenges, and provide an outlook on future development trends in ECZIBs. We hope this concise review will offer valuable guidance and inspire further research, ultimately fostering new breakthroughs in this emerging field.

Abstract A thin tungsten filament glowing without boiling in helium-4 is a classic and widely used demonstration of infinite thermal conductivity of superfluidity. Under normal conditions, the filament exhibits Ohmic conductivity, referred to as "cold" state. However, this behavior abruptly changes when a helium vapor bubble forms around the filament, which is referred to as the "hot" state. The intense thermal counterflow generated by the hot filament can trigger turbulence within the superfluid. To investigate this quantum turbulence, which attenuates second sound, we constructed a second-sound resonator. A tungsten filament was positioned in the center of the resonator to create a radial thermal counterflow, serving as a source of turbulence. Our observations reveal that the attenuation of the second-sound resonance correlates with the filament’s Joule heating power. Surprisingly, quantum turbulence associated with thermal counterflow affects second-sound attenuation in markedly different ways depending on whether the filament is in the cold or hot state—even when the Joule heating power remains the same.

Abstract One-dimensional (1D) topological insulators provide a minimal setting for bulk-boundary correspondence, hosting symmetryprotected zero-dimensional (0D) end and domain-wall states. This review summarizes the 1D symmetries and topological invariants that protect these modes, and surveys experimental signatures used to identify them, including in-gap spectral weight, spatial localization, robustness to perturbations, and electrical tunability. We contrast engineered and intrinsic platforms, such as atom-by-atom assembled chains, self-organized Peierls systems, on-surface synthesized graphene nanoribbon superlattices, quantum spin Hall edges confined to the 1D limit, and quasi-1D chain materials where crystalline symmetries protect end states. We close with an outlook on electrically controllable end states and device-motivated directions enabled by robust, discrete 0D modes.

Abstract We review recent advances in Klein and anti-Klein tunneling in one-and two-dimensional materials. Using a general tight-binding framework applied to multiple periodic systems, we establish the criteria for the emergence of Klein tunneling based on the conservation of an effective reduced pseudospin. The inclusion of higher-order terms in the wave vector leads to nontrivial matching conditions for wave scattering at interfaces. We further examine the emergence of multiple types of Klein tunneling in two-dimensional materials beyond graphene, including phosphorene and borophene, as well as in one-dimensional systems such as Su-Schrieffer-Heeger lattices. Finally, we discuss how these tunneling phenomena can be tested in both synthesized and artificial lattices, including elastic metamaterials, optical, photonic, phononic, and superconducting platforms, demonstrating the universality of Klein tunneling across different wave natures and length scales.

Abstract Liquid Ga is considered to be in a mixed state of metallic and covalent local states, and shows complex behavior, similar to those of other polyvalent Group III-V elements on the Periodic Table, such as Si, Ge, Sn, and Bi. We studied liquid Ga by inelastic neutron scattering to obtain the pair-distribution function. We found that the structure of liquid Ga has the medium-range order characterized by two overlapping density waves (DWs), one originating from ionic repulsion and the other due to electronic driving force to create charge density waves. We suggest that the dual DW state is naturally elucidated by the density wave theory, rather than the widely used Ornstein-Zernike theory. 

such as Si, Ge, Sn, and Bi. We studied liquid Ga by inelastic neutron scattering to obtain the pairdistribution function. We found that the structure of liquid Ga has the medium-range order characterized by two overlapping density waves (DWs), one originating from ionic repulsion and the other due to electronic driving force to create charge density waves. We suggest that the dual DW state is naturally elucidated by the density wave theory, rather than the widely used Ornstein-Zernike theory..

Abstract We present a mode-resolved analysis of electron-phonon interactions in lithium under extreme conditions that identifies protected regions of k-space. The Li BCC phase exhibits topologically protected degenerate bands at the Fermi level that inhibit superconductivity by preventing gap formation via electron-phonon coupling. In contrast, the 9R and cl16 phase lacks the relevant symmetry protection. In the 9R phase, the strong electron-phonon interactions dynamically couple to degenerate valence and conduction bands opening an energy gap and lowering the ground-state energy. This stabilization energy, though small in magnitude, is comparable to the total energy difference between the BCC and 9R phases. Through mode-resolved calculations, we identify distinctive electron-phonon interaction patterns, including pole-like non-adiabatic coupling terms, localized spikes indicative of topological protection, and broad parabolic regions associated with conventional coupling. The same framework localizes the soft-mode instability in high-pressure FCC Li to a highly confined strong-coupling pocket in k-space (near X), with rapid suppression away from that point by symmetry-driven protection. We introduce the concept of "topological superposition energy," a quantum stabilization mechanism arising from the coherent mixing of conduction and valence states mediated by lattice vibrations. Near quasi-degenerate doublets, we show that these pole-like features directly reflect large lattice nonadiabatic coupling terms (NACTs), providing a quantitative link between the curvature fingerprints and interband derivative couplings. We further map the most strongly coupled doublets onto a mode-resolved spin–boson Hamiltonian, using the ratio of degeneracy lifting energy and phonon energy to gauge how effectively a phonon mode can drive degeneracy lifting and gap formation across the different Li phases. This mode-resolved, non-adiabatic approach thus converts electron–phonon data into a predictive k-space atlas of where symmetry blocks or enables gap formation, reconciling low-temperature and pressure-induced behavior in elemental lithium and offering a transferable recipe for other quantum materials.

To address persistent complications in diabetic wound healing, we present a photothermally responsive, multifunctional hydrogel. This system, integrating bioactive carbon nanomaterials into a chitosan network, is meticulously designed for comprehensive microenvironment regulation. Characterized by practical physical attributes such as injectability, self-healing capabilities, and sustained active component release, the hydrogel further offers a powerful suite of bioactive functionalities. It effectively combines potent antioxidant and antibacterial activities with a crucial ability to modulate immune responses, particularly by steering macrophage polarization toward a pro-regenerative phenotype. These therapeutic benefits are notably amplified by a photothermal effect, specifically derived from the magnesium-doped carbon dots. In vivo studies confirm this system significantly accelerates infected wound healing through synergistic bacterial eradication, inflammation suppression, and enhanced angiogenesis. This multimechanistic approach represents a significant step forward, offering a transformative material solution with strong potential to improve clinical outcomes for severe diabetic wounds.

The zero-excess lithium metal batteries (ZELMBs) offer a higher energy density and better manufacturing safety compared with the conventional LMBs. However, the practical application of such cells is hindered by the severe dendrite growth originating from the uneven Li+ distribution at the copper substrate. Here, we combine a top layer of polyacrylonitrile (PAN) and a bottom layer of poly(vinylidene difluoride) (PVDF), fabricated by electrospinning, to serve as an artificial solid electrolyte interphase (ASEI) promoting membrane, denoted as Cu@PAN + PVDF, for effectively dealing with this challenge. This configuration facilitates the desolvation and uniform flux of Li+, leading to form an inorganic-rich SEI layer to favor the uniform lithium deposition. In contrast, reversing the layer order (i.e., PVDF as the top layer and PAN as the bottom layer, denoted as Cu@PVDF + PAN) results in a high nucleation barrier and an uneven lithium deposit. The morphological evolution is further examined using a newly designed half-stripping experiment where lithium is plated and partially stripped at 1 mA cm–2 for 1 and 0.5 h, respectively. The Cu@PAN + PVDF electrode maintains a dense, uniform surface, whereas Cu@PVDF + PAN exhibits midlayer voids and disconnected “dead Li”, indicating the uneven delithiation. The Cu@PAN + PVDF||Li half-cell achieves over 160 cycles with a Coulombic efficiency (CE) exceeding 95%, outperforming the Cu@PVDF + PAN||Li (100 cycles) and bare Cu||Li (110 cycles) cells. This work identifies layer orientation as a governing parameter for the ASEI design and introduces a practical half-stripping methodology for evaluating the interfacial reversibility of the negative electrode in ZELMBs.

The nervous system processes information by translating chemical signals into electrical and biochemical responses, ultimately driving biological adaptation and computation. Chemical synapses are the primary communication channels between neurons, operating with remarkable speed and precision to enable complex neural information processing. In this perspective, we focus on these native signaling principles and explore the potential of synaptic structures as neurointerface modules. Building on this view, we argue that electrodes can be engineered to function as complementary synaptic terminals, enabling neuron–device communication that directly leverages the chemical, electrical, and biological logic of neural systems. In particular, we discuss whether synaptic cell adhesion molecules can be harnessed as synaptogenic cues to redefine electrode surfaces as functional synaptic counterparts of neuronal terminals, and we examine the distinctive properties and emerging applications of such interfaces.

We report an interfacial chemical stability-driven reduction of low-temperature damping losses in tensile-strained, ultrathin Y₃Fe₅O₁₂ (YIG) films grown by pulsed laser deposition, exhibiting ultralow room-temperature damping constants and tunable magnetic anisotropy. Comparative broadband FMR measurements show that tensile-strained YIG films on Gd₃Sc₂Ga₃O₁₂ (GSGG) retain measurable damping even at nanometer thicknesses and cryogenic temperatures down to 2 K, outperforming relaxed films on Gd₃Ga₅O₁₂. Based on static magnetometry measurements along with microstructural and compositional analyses, we attribute these enhanced dynamic properties to the suppression of interdiffusion across the YIG/GSGG interface, resulting from enhanced chemical stability and favorable growth kinetics by the presence of Sc. Our findings highlight the importance of chemical and kinetic factors in achieving a few-nanometer-thick YIG film with negligible low-temperature damping dissipation and perpendicular magnetic anisotropy for cryogenic spintronic applications.

Laccases, a typical metalloenzyme, catalyze the oxidation of organic substrates while reducing molecular oxygen to water. Reconstructing the in-between states (IBS) of the laccase active site is essential for understanding its catalytic mechanism and for guiding artificial enzyme design. In this study, we designed a peptide-metal coassembly using amyloid peptides with copper ions, forming stable and ordered structures. Structural characterization confirms β-sheet formation stabilized by Cu2+ coordination, providing a robust framework for catalysis. Computational analysis reveals the copper coordination geometry and catalytic electronic properties, demonstrating the realization of the key IBS at the active site of the assembly. Subsequent experimental validation confirms the significant laccase-like activity of the peptide-metal coassemblies even under challenging conditions of varying pH, temperature, and prolonged storage. This highlights their resilience and sustained catalytic efficiency, making them promising candidates for industrial and environmental applications. This study provides a comprehensive understanding of peptide-metal coassemblies as laccase mimetics, laying the groundwork for the rational design of more efficient and versatile catalytic systems for industrial and environmental applications.