Featured
-
-
Article
| Open AccessThree-stage ultrafast demagnetization dynamics in a monolayer ferromagnet
Ultrafast demagnetization refers to the process where an intense optical drive can destroy the magnetic order in a magnetic material on a femto-second timescale. Here, Wu et al resolve a three-stage ultrafast demagnetization process in a monolayer of Fe3GeTe2.
- Na Wu
- , Shengjie Zhang
- & Sheng Meng
-
Article
| Open AccessCharge state-dependent symmetry breaking of atomic defects in transition metal dichalcogenides
The microscopic structure of quantum defects in 2D materials is crucial to understand their optical properties and spin-photon interface. Here, the authors report the direct imaging of charge state-dependent symmetry breaking of sulfur vacancies and rhenium dopants in 2D MoS2, showing evidence of a Jahn-Teller effect.
- Feifei Xiang
- , Lysander Huberich
- & Bruno Schuler
-
Article
| Open AccessReversible non-volatile electronic switching in a near-room-temperature van der Waals ferromagnet
The controlled manipulation of the topological phases of electronic materials is a central goal of modern condensed matter research. Here, the authors demonstrate controllable switching between two distinct topological phases in a layered ferromagnet via thermal cycling.
- Han Wu
- , Lei Chen
- & Ming Yi
-
Article
| Open AccessAnomalous anti-Kasha excited-state luminescence from symmetry-breaking heterogeneous carbon bisnanohoops
It is a long-standing scientific controversy to achieve anti-Kasha emissions by tuning structures at a molecular level. Herein, the authors constructed two symmetry-breaking heterogeneous carbon bisnanohoops with unusual anti-Kasha characteristics.
- Xinyu Zhang
- , Cheng Chen
- & Pingwu Du
-
Article
| Open AccessLayer-polarized ferromagnetism in rhombohedral multilayer graphene
Rhombohedral multilayer graphene has emerged as an exciting solid-state platform for studying correlated electron physics. Here, the authors demonstrate field-tunable layer-polarized ferromagnetism and isolated surface flat bands engineered with a moiré potential.
- Wenqiang Zhou
- , Jing Ding
- & Shuigang Xu
-
Article
| Open AccessElectrically driven amplification of terahertz acoustic waves in graphene
Electron–phonon interactions are a crucial aspect of high-quality graphene devices. Here, the authors show that graphene resistivity grows strongly in the direction of the carrier flow when the drift velocity exceeds the speed of sound due to the electrical amplification of acoustic terahertz phonons.
- Aaron H. Barajas-Aguilar
- , Jasen Zion
- & Javier D. Sanchez-Yamagishi
-
Article
| Open AccessSpin-orbital Jahn-Teller bipolarons
The interplay between electron-phonon and spin-orbit interactions has led to the concept of a spin-orbit polaron. Here the authors show that such a regime is realized in a spin-orbit-coupled Mott insulator, leading to a new polaron quasiparticle, and study its effect on the Mott metal-insulator transition.
- Lorenzo Celiberti
- , Dario Fiore Mosca
- & Cesare Franchini
-
Article
| Open AccessThree-dimensional ultrafast charge-density-wave dynamics in CuTe
Some materials host multiple charge density wave states, however, their dynamics and the nature of phase transitions are often unclear. Here, using temperature and orientation resolved ultrafast spectroscopy, the authors reveal charge density waves of different dimensionality in CuTe and elucidate their mechanism.
- Nguyen Nhat Quyen
- , Wen-Yen Tzeng
- & Chih-Wei Luo
-
Article
| Open AccessRevealing Fermi surface evolution and Berry curvature in an ideal type-II Weyl semimetal
The authors study the field-induced ferromagnetic state of MnBi2-xSbxTe4 by quantum oscillations and high-field Hall effect measurements. They confirm a single pair of type-II Weyl nodes, the long-sought “ideal” Weyl semimetal.
- Qianni Jiang
- , Johanna C. Palmstrom
- & Jiun-Haw Chu
-
Article
| Open AccessHigher order gaps in the renormalized band structure of doubly aligned hBN/bilayer graphene moiré superlattice
In moiré superlattices, a multitude of higher order Bragg gaps and van Hove singularities emerges as the band structure renormalizes. Here, the authors map these gaps uniquely to the recently predicted topological Bragg indices of the underlying supermoiré lattice.
- Mohit Kumar Jat
- , Priya Tiwari
- & Aveek Bid
-
Article
| Open AccessTheory of resonantly enhanced photo-induced superconductivity
The authors theoretically propose a simple microscopic mechanism for light-induced superconductivity based on a boson coupled to an electronic interband transition. The electron-electron attraction needed for the superconductivity can be resonantly amplified when the boson’s frequency is close to the energy difference between the two electronic bands. The model can be engineered using a 2D heterostructure.
- Christian J. Eckhardt
- , Sambuddha Chattopadhyay
- & Marios H. Michael
-
Article
| Open AccessThe discovery of three-dimensional Van Hove singularity
Van Hove singularities (VHS) are believed to exist in one and two dimensions, but rarely found in three dimensions (3D). Here the authors report the discovery of 3D VHS in a topological magnet EuCd2As2 by magneto-infrared spectroscopy.
- Wenbin Wu
- , Zeping Shi
- & Xiang Yuan
-
Article
| Open AccessUnveiling diverse coordination-defined electronic structures of reconstructed anatase TiO2(001)-(1 × 4) surface
By measuring in energy, momentum and real space, the authors unveil diverse coordination environments and electronic structures on the reconstructed anatase TiO2(001), giving insights into its structure-property relationship with atomic precision.
- Xiaochuan Ma
- , Yongliang Shi
- & Bing Wang
-
Article
| Open AccessElectrostatic potentials of atomic nanostructures at metal surfaces quantified by scanning quantum dot microscopy
Surface averaging techniques offer only limited access to the electrostatic potentials of nanostructures, which are determined by shape, material, and environment. Here, the authors quantify these potentials for gold and silver adatom chains, explaining the mechanisms of dipole formation.
- Rustem Bolat
- , Jose M. Guevara
- & Christian Wagner
-
Article
| Open AccessTuning of the flat band and its impact on superconductivity in Mo5Si3−xPx
R. Khasanov et al. report thermodynamic and muon-spin-rotation measurements on the Mo5Si3−xPx superconducting family. They find that a flat band reaches the Fermi level at x ≃ 1.3, leading to enhancement of electronic correlations and an abrupt change of the superconducting properties.
- Rustem Khasanov
- , Bin-Bin Ruan
- & Zurab Guguchia
-
Article
| Open AccessDirect observation of altermagnetic band splitting in CrSb thin films
The fundamental hallmark of altermagnetism lies in the spin splitting of electronic valence bands. Here, the authors observe splitting in metallic CrSb, revealing an exceptionally large value and energetic placement just below the Fermi energy.
- Sonka Reimers
- , Lukas Odenbreit
- & Martin Jourdan
-
Article
| Open AccessQuantifying the photocurrent fluctuation in quantum materials by shot noise
The bulk photovoltaic effect and DC photocurrent generation can be used to detect topology and geometry in non-centrosymmetric quantum materials. Here, the authors theoretically propose the detection of DC shot noise as a diagnostic tool for the characterization of the band quantum geometry under relaxed symmetry conditions.
- Longjun Xiang
- , Hao Jin
- & Jian Wang
-
Article
| Open AccessPrediction of highly stable 2D carbon allotropes based on azulenoid kekulene
Discovery of 2D materials with useful electronic properties is challenging. Here, the authors use DFT to design a stable semiconducting 2D carbon allotrope for optoelectronic applications that has light charge carriers and unusual secondary bandgap.
- Zhenzhe Zhang
- , Hanh D. M. Pham
- & Rustam Z. Khaliullin
-
Article
| Open AccessCompeting itinerant and local spin interactions in kagome metal FeGe
FeGe is a Kagome metal that exhibits a very rich array of magnetic and electronic phases. Here, using neutron scattering, Chen et al add to this zoo, by showing the emergence of a spin density wave order.
- Lebing Chen
- , Xiaokun Teng
- & Pengcheng Dai
-
Article
| Open AccessDisentangling the multiorbital contributions of excitons by photoemission exciton tomography
Understanding excitonic optical excitations is integral to improving optoelectronic and photovoltaic semiconductor devices. Here, Bennecke et al. use photoemission exciton tomography to unravel the multiorbital electron and hole contributions of entangled excitonic states in the prototypical organic semiconductor C60.
- Wiebke Bennecke
- , Andreas Windischbacher
- & Stefan Mathias
-
Article
| Open AccessFinite-momentum Cooper pairing in proximitized altermagnets
An altermagnet has highly anisotropic spin splitting but zero net magnetization. Here, S.-B. Zhang et al. theoretically study the behavior of s-wave superconductor/altermagnet hybrid structures, finding that Cooper pairs in the proximitized altermagnet have an anisotropic non-zero momentum.
- Song-Bo Zhang
- , Lun-Hui Hu
- & Titus Neupert
-
Article
| Open AccessEngineering surface dipoles on mixed conducting oxides with ultra-thin oxide decoration layers
Improving materials for energy devices relates to an optimisation of their surfaces. Here authors show that surface modification with ultrathin oxide layers allows for a tailoring of the surface dipole and the work function of mixed ionic and electronic conducting oxides.
- Matthäus Siebenhofer
- , Andreas Nenning
- & Markus Kubicek
-
Article
| Open AccessPhase-selective in-plane heteroepitaxial growth of H-phase CrSe2
Phase engineering of 2D transition metal dichalcogenides enables the investigation of emerging physical properties. Here, the authors report a phase selective in-plane heteroepitaxial method to grow semiconducting H-phase CrSe2 thin films from MoSe2 nanoribbons, showing Tomonaga-Luttinger liquid behaviour in the CrSe2 mirror twin boundaries.
- Meizhuang Liu
- , Jian Gou
- & Andrew T. S. Wee
-
Article
| Open AccessPhonon promoted charge density wave in topological kagome metal ScV6Sn6
The mechanism of charge density wave order in V-based kagome metals has been debated. Here the authors use a range of experimental techniques combined with ab initio calculations to study the electronic structure and phonon modes of ScV6Sn6, revealing the dominant role of strong electron-phonon coupling.
- Yong Hu
- , Junzhang Ma
- & Ming Shi
-
Article
| Open AccessCrystal-chemical origins of the ultrahigh conductivity of metallic delafossites
Certain delafossite materials are the most conductive oxides known, for poorly understood reasons. This work elucidates this finding by uncovering a sublattice purification mechanism that enables ultrapure conductive planes even in impure crystals.
- Yi Zhang
- , Fred Tutt
- & Chris Leighton
-
Article
| Open AccessHeavy fermions vs doped Mott physics in heterogeneous Ta-dichalcogenide bilayers
Recent experiments reported the Kondo effect in 1H/1T dichalcogenide hetero-bilayers. Crippa et al. re-examine this interpretation using ab initio calculations and dynamical mean-field theory demonstrating strong charge transfer sensitive to the interlayer separation, indicative of a doped Mott insulator regime.
- Lorenzo Crippa
- , Hyeonhu Bae
- & Roser Valentí
-
Article
| Open AccessInteracting topological quantum chemistry in 2D with many-body real space invariants
While the classification of single-particle topological phases has been established, recent efforts have been made to extend it to interacting limit. Here the authors present a classification of interacting topological systems in 2D based on the generalization of real space invariants.
- Jonah Herzog-Arbeitman
- , B. Andrei Bernevig
- & Zhi-Da Song
-
Article
| Open AccessSurface triggered stabilization of metastable charge-ordered phase in SrTiO3
Charge order has been typically reported in doped systems with high d-electron occupancy. Here the authors demonstrate a charge-ordered insulating state in a La-doped SrTiO3 epitaxial film which has the lowest d-electron occupancy and attribute it to surface distortion that favours electron-phonon coupling.
- Kitae Eom
- , Bongwook Chung
- & Jaichan Lee
-
Article
| Open AccessRealization of large-area ultraflat chiral blue phosphorene
Blue phosphorene (BlueP) is a 2D phosphorus allotrope predicted to host Dirac fermions and other interesting electronic properties. Here, the authors report the growth of large-area BlueP films with ordered chiral nanostructures on Cu(111) substrates, expanding the range of its potential applications.
- Ye-Heng Song
- , M. U. Muzaffar
- & Zhenyu Zhang
-
Article
| Open AccessDeceptive orbital confinement at edges and pores of carbon-based 1D and 2D nanoarchitectures
The apparent electronic confinement at nanographene boundaries in scanning tunneling microscopy/spectroscopy is often misinterpreted. Here, the authors explain this phenomenon in terms of the decay of frontier orbitals and confinement at the edges of graphene nanoribbons and pores in nanoporous graphene.
- Ignacio Piquero-Zulaica
- , Eduardo Corral-Rascón
- & Johannes V. Barth
-
Article
| Open AccessCharge-density wave mediated quasi-one-dimensional Kondo lattice in stripe-phase monolayer 1T-NbSe2
The realization of heavy-fermion physics in van der Waals materials with d-electrons has attracted attention recently. Here the authors present evidence for a quasi-1D Kondo lattice in monolayer NbSe2, driven into a stripe phase by Se-deficient line defects created during growth.
- Zhen-Yu Liu
- , Heng Jin
- & Ying-Shuang Fu
-
Article
| Open AccessDual Higgs modes entangled into a soliton lattice in CuTe
The Higgs mode in condensed matter physics refers to the oscillations of the amplitude of the order parameter, and single Higgs modes have been studies in various systems. Here the authors report real-space observation of two coupled Higgs modes in a 1D charge density wave phase of CuTe.
- SeongJin Kwon
- , Hyunjin Jung
- & Han Woong Yeom
-
Article
| Open AccessHigh-throughput computational stacking reveals emergent properties in natural van der Waals bilayers
2D bilayers have recently attracted significant attention due to fundamental properties like interlayer excitons and interfacial ferroelectricity. Here, the authors report a density functional theory approach to identify 2586 stable homobilayer systems and calculate their stacking-dependent electronic, magnetic and vibrational properties.
- Sahar Pakdel
- , Asbjørn Rasmussen
- & Kristian S. Thygesen
-
Article
| Open AccessElectrically induced cancellation and inversion of piezoelectricity in ferroelectric Hf0.5Zr0.5O2
Hf0.5Zr0.5O2 ferroelectric capacitors undergo a continuous transition from a positive effective to a fully inverted negative piezoelectric coefficient d33 upon electrical cycling. With proper ac training, both the net effective and the local piezoresponses can be nullified while the polarization is kept fully switchable.
- Haidong Lu
- , Dong-Jik Kim
- & Catherine Dubourdieu
-
Article
| Open AccessSupercurrent mediated by helical edge modes in bilayer graphene
P. Rout et al. study Josephson junctions where the weak link is WSe2-encapsulated bilayer graphene, which features helical edge modes. They argue that the supercurrent channels along opposite edges of the weak link are coupled by a circulating helical mode.
- Prasanna Rout
- , Nikos Papadopoulos
- & Srijit Goswami
-
Article
| Open AccessTwo-component nematic superconductivity in 4Hb-TaS2
I. Silber et al. discover a two-fold symmetry of the superconducting upper critical field in hexagonal 4Hb-TaS2 just below Tc, a clear signature of nematic, two-component superconductivity. They further suggest a theoretical model that reconciles the nematic superconductivity with the previously-observed time-reversal-symmetry-breaking in this material.
- I. Silber
- , S. Mathimalar
- & Y. Dagan
-
Article
| Open AccessUltrafast and persistent photoinduced phase transition at room temperature monitored by streaming powder diffraction
Photoinduced phase transitions occur in a variety of materials and allow for the optical control of the materials properties. Here, Herve et al present a streaming powder X-ray diffraction method allowing them to study the ultrafast photoinduced phase transition of Rb0.94Mn0.94Co0.06[Fe(CN)6]0.9 within thermal hysteresis.
- Marius Hervé
- , Gaël Privault
- & Eric Collet
-
Article
| Open AccessTowards near-term quantum simulation of materials
The use of NISQ devices for useful quantum simulations of materials and chemistry is still mainly limited by the necessary circuit depth. Here, the authors propose to combine classically-generated effective Hamiltonians, hybrid fermion-to-qubit mapping and circuit optimisations to bring this requirement closer to experimental feasibility.
- Laura Clinton
- , Toby Cubitt
- & Evan Sheridan
-
Article
| Open AccessGiant tunnelling electroresistance in atomic-scale ferroelectric tunnel junctions
The authors report ferroelectric tunnel junctions based on samarium-substituted layered bismuth oxide, which show tunnelling electroresistance of 7 × 105 and high endurance over 5 billion cycles, even when the film is down to one nanometer.
- Yueyang Jia
- , Qianqian Yang
- & Rui Yang
-
Article
| Open AccessUnraveling the crucial role of trace oxygen in organic semiconductors
Conventional deoxygenation methods typically result in inevitable trace oxygen residue in organic semiconductors. Here, Huang et al. reports a non-destructive soft-plasma treatment for deoxygenation and that removal of trace oxygen can be used to modulate p-type characteristics.
- Yinan Huang
- , Kunjie Wu
- & Wenping Hu
-
Article
| Open AccessSpin-resolved topology and partial axion angles in three-dimensional insulators
3D higher-order topological insulators (HOTIs) exhibit 1D hinge states depending on extrinsic sample details, while intrinsic features of HOTIs remain unknown. Here, K.S. Lin et al. introduce the framework of spin-resolved topology to show that helical HOTIs can realize a doubled axion insulator phase with nontrivial partial axion angles.
- Kuan-Sen Lin
- , Giandomenico Palumbo
- & Barry Bradlyn
-
Article
| Open AccessField-induced bound-state condensation and spin-nematic phase in SrCu2(BO3)2 revealed by neutron scattering up to 25.9 T
SrCu2(BO3)2 realizes the Shastry-Sutherland model (SSM), a 2D frustrated dimer model. Here, via high-magnetic-field inelastic neutron scattering measurements and matrix-product-state calculations, Fogh et al. find evidence for Bose-Einstein condensation of S = 2 two-triplon bound states, which is a spin-nematic phase.
- Ellen Fogh
- , Mithilesh Nayak
- & Henrik M. Rønnow
-
Article
| Open AccessElectrically and mechanically driven rotation of polar spirals in a relaxor ferroelectric polymer
Polar spirals induced in a relaxor ferroelectric can be quasi-continuously rotated by applying electric/mechanical fields, due to an asymmetric Coulomb interaction. The rotations are non-volatile with robust retention, and can be optically read out.
- Mengfan Guo
- , Erxiang Xu
- & Yang Shen
-
Article
| Open AccessQuasi-2D Fermi surface in the anomalous superconductor UTe2
A. G. Eaton et al. directly probe the Fermi surface of the candidate triplet superconductor UTe2 by measuring magnetic quantum oscillations in ultra-pure crystals. By comparison with model calculations, the data are found to be consistent with a Fermi surface that consists of two cylindrical sections of electron and hole-type respectively.
- A. G. Eaton
- , T. I. Weinberger
- & M. Vališka
-
Article
| Open AccessFractional quantum ferroelectricity
A concept of fractional quantum ferroelectricity is proposed, where the direction of ferroelectric polarization difference no longer subjects to the symmetry restrictions of Neumann’s principle. It indicates that ferroelectricity can exist in nonpolar systems, which may lead to discovery of many overlooked ferroelectrics.
- Junyi Ji
- , Guoliang Yu
- & H. J. Xiang
-
Article
| Open AccessOrbital perspective on high-harmonic generation from solids
Here the authors identify real-space contributions to the characteristics of high-harmonic generation in ReS2 and demonstrate the possibility of laser-controlled emission. They find that the spectrum is not just determined by the band structure, but also by the interference between HHG signals coming from different atoms within the unit cell.
- Álvaro Jiménez-Galán
- , Chandler Bossaer
- & Giulio Vampa
-
Article
| Open AccessA coherent phonon-induced hidden quadrupolar ordered state in Ca2RuO4
Ultrafast laser excitation can generate metastable states in quantum materials, with no counterpart in equilibrium. Here the authors demonstrate a transient quadrupolar ordered state in Ca2RuO4 single crystals via excitation of a phonon mode coupled to the order parameter.
- Honglie Ning
- , Omar Mehio
- & David Hsieh
-
Article
| Open AccessLarge scale purification in semiconductors using Rydberg excitons
Charged impurities are a major source of charge noise in semiconductors. Here, using pump-probe time-resolved relative transmission measurements on cuprous oxide, the authors demonstrate a strategy for mitigating charged impurities by injection and subsequent breakdown of Rydberg excitons.
- Martin Bergen
- , Valentin Walther
- & Marc Aßmann
-
Article
| Open AccessA microscopic Kondo lattice model for the heavy fermion antiferromagnet CeIn3
Kondo materials exhibit extremely rich physics, from unconventional superconductivity to topological phases. Unfortunately, for a real material, direct solution of the Kondo lattice is practically impossible. Here, Simeth et al. present a tractable approach to this problem, showing how a multi-orbital periodic Anderson model can be reduced to a Kondo lattice model, and be applied to relevant materials and quantitatively validated with neutron spectroscopy.
- W. Simeth
- , Z. Wang
- & M. Janoschek