Stacking-Dependent Correlated Gap and Kondo Peak in the Heterophase Bilayer with Picometer-Level Interlayer Shift.

Two-dimensional heterojunctions provide a versatile platform for exploring various quantum properties. Here, we create bilayer 1T/2H-NbSe heterophase junctions and realize two types of stacking configurations with picometer-level lattice shifts. By high-resolution scanning tunneling microscopy/spectroscopy, we found that the electronic states are highly dependent on the stacking configurations of the 1T layer on the 2H one.

Twist-Dependent Semiconductor-to-Metal Transition in Epitaxial Bilayer α-Antimonene.

In spite of the observation of various exotic correlated physics in twisted graphene and transition metal dichalcogenides, it remains a great challenge to prepare twisted bilayers of puckered elemental layered crystals in the developing field of twistronics. Here, we report the first discovery and success in epitaxial growth of the 39°-twisted bilayer α-Sb. Molecular dynamics simulations verify that the 39°-twisted bilayer α-Sb is energetically stable, consistent with the experiments.

Cornertronics in Two-Dimensional Second-Order Topological Insulators.

Traditional electronic devices rely on the electron's intrinsic degrees of freedom (d.o.f.

Charge-Selective 2D Heterointerface-Driven Multifunctional Floating Gate Memory for In Situ Sensing-Memory-Computing.

Flash memory, dominating data storage due to its substantial storage density and cost efficiency, faces limitations such as slow response, high operating voltages, absence of optoelectronic response, etc., hindering the development of sensing-memory-computing capability. Here, we present an ultrathin platinum disulfide (PtS)/hexagonal boron nitride (hBN)/multilayer graphene (MLG) van der Waals heterojunction with atomically sharp interfaces, achieving selective charge tunneling behavior and demonstrating ultrafast operations, a high on/off ratio (10), extremely low operating voltage, robust endurance (10 cycles), and retention exceeding 10 years.

Detonation performance and shock sensitivity of energetic material NTO with embedded small molecules: a deep neural network potential accelerated molecular dynamics study.

Accurate description of detonation performance for explosives remains a challenge for current experimental and theoretical methodologies. Herein, we address this issue through combining a multi-scale shock technique and a first-principles based deep neural network potential. This approach enables us to conduct molecular dynamics simulations encompassing over a thousand atoms and extending for several nanoseconds, allowing us to evaluate the detonation performance of the insensitive explosive NTO crystal.

Fully Polarized Topological Isostatic Metamaterials in Three Dimensions.

Topological surface states are unique to topological materials and are immune to disturbances. In isostatic lattices, mechanical topological floppy modes exhibit softness depending on the polarization relative to the terminating surface. However, in three dimensions, the polarization of topological floppy modes is disrupted by the ubiquitous mechanical Weyl lines.

Rich magnon topology in triangular lattice magnets.

The two-dimensional magnet has been an emerging and rapidly growing field. The nontrivial topological phenomenon in these materials is an attracting subject. Yet, the realization of such magnets exhibiting topological magnons remains a challenge.

Evidence for time-reversal symmetry-breaking kagome superconductivity.

Superconductivity and magnetism are often antagonistic in quantum matter, although their intertwining has long been considered in frustrated-lattice systems. Here we utilize scanning tunnelling microscopy and muon spin resonance to demonstrate time-reversal symmetry-breaking superconductivity in kagome metal Cs(V, Ta)Sb, where the Cooper pairing exhibits magnetism and is modulated by it. In the magnetic channel, we observe spontaneous internal magnetism in a fully gapped superconducting state.

Chiral kagome superconductivity modulations with residual Fermi arcs.

Superconductivity involving finite-momentum pairing can lead to spatial-gap and pair-density modulations, as well as Bogoliubov Fermi states within the superconducting gap. However, the experimental realization of their intertwined relations has been challenging. Here we detect chiral kagome superconductivity modulations with residual Fermi arcs in KVSb and CsVSb using normal and Josephson scanning tunnelling microscopy down to 30 millikelvin with a resolved electronic energy difference at the microelectronvolt level.

Predictable Gate-Field Control of Spin in Altermagnets with Spin-Layer Coupling.

Spintronics, a technology harnessing electron spin for information transmission, offers a promising avenue to surpass the limitations of conventional electronic devices. While the spin directly interacts with the magnetic field, its control through the electric field is generally more practical, and has become a focal point in the field. Here, we propose a mechanism to realize static and almost uniform effective magnetic field by gate-electric field.

Robust Edge States of Quasi-1D Material TaNiSe and Applications in Saturable Absorbers.

The helical edge states (ESs) protected by underlying topology in two-dimensional topological insulators (TIs) arouse upsurges in saturable absorptions thanks to the strong photon-electron coupling in ESs. However, limited TIs demonstrate clear signatures of topological ESs at liquid nitrogen temperatures, hindering the applications of such exotic quantum states. Here, we demonstrate the existence of one-dimensional (1D) ESs at the step edge of the quasi-1D material TaNiSe at 78 K by scanning tunneling microscopy.

Evidence for Two-Dimensional Weyl Fermions in Air-Stable Monolayer PtTe.

The Weyl semimetals represent a distinct category of topological materials wherein the low-energy excitations appear as the long-sought Weyl Fermions. Exotic transport and optical properties are expected because of the chiral anomaly and linear energy-momentum dispersion. While three-dimensional Weyl semimetals have been successfully realized, the quest for their two-dimensional (2D) counterparts is ongoing.

Conventional superconductivity in the doped kagome superconductor Cs(VTa)Sb from vortex lattice studies.

A hallmark of unconventional superconductors is a complex electronic phase diagram where intertwined orders of charge-spin-lattice degrees of freedom compete and coexist. While the kagome metals such as CsVSb also exhibit complex behavior, involving coexisting charge density wave order and superconductivity, much is unclear about the microscopic origin of the superconducting pairing. We study the vortex lattice in the superconducting state of Cs(VTa)Sb, where the Ta-doping suppresses charge order and enhances superconductivity.

Colossal anomalous Hall effect in the layered antiferromagnetic EuAlSi compound.

The anomalous Hall effect (AHE), significantly enhanced by the extrinsic mechanism, has attracted attention for its almost unlimited Hall response, which exceeds the upper limit of the Berry curvature mechanism. However, due to the high conductivity in the clean regime and weak skew scattering, it is a great challenge to obtain large anomalous Hall conductivities and large anomalous Hall angles at the same time. Here, we unveil a new magnetic metal system, EuAlSi, which hosts both colossal anomalous Hall conductivity (Axy ≥ 10 Ω cm) and large anomalous Hall angle (AHA >10%).

Three-dimensional hidden phase probed by in-plane magnetotransport in kagome metal CsVSb thin flakes.

Transition metal compounds with kagome structure have been found to exhibit a variety of exotic structural, electronic, and magnetic orders. These orders are competing with energies very close to each other, resulting in complex phase transitions. Some of the phases are easily observable, such as the charge density wave (CDW) and the superconducting phase, while others are more challenging to identify and characterize.

Quasi-Homoepitaxial Growth of Highly Strained Alkali-Metal Ultrathin Films on Kagome Superconductors.

Applying lattice strain to thin films, a critical factor to tailor their properties such as stabilizing a structural phase unstable at ambient pressure, generally necessitates heteroepitaxial growth to control the lattice mismatch with substrate. Therefore, while homoepitaxy, the growth of thin film on a substrate made of the same material, is a useful method to fabricate high-quality thin films, its application to studying strain-induced structural phases is limited. Contrary to this general belief, here the quasi-homoepitaxial growth of Cs and Rb thin films is reported with substantial in-plane compressive strain.

Superconducting diode effect and interference patterns in kagome CsVSb.

The interplay among frustrated lattice geometry, non-trivial band topology and correlation yields rich quantum states of matter in kagome systems. A series of recent members in this family, AVSb (A = K, Rb or Cs), exhibit a cascade of symmetry-breaking transitions, involving the 3Q chiral charge ordering, electronic nematicity, roton pair density wave and superconductivity. The nature of the superconducting order is yet to be resolved.