Condensed-matter physics

  • Article
    | Open Access

    The majority of polar structures emerging naturally in ferroelectrics are topologically trivial. Here, the authors demonstrate reconstruction of topologically trivial strip-like domain architecture into arrays of polar vortex in (PbTiO3)10/(SrTiO3)10 superlattice.

    • Congbing Tan
    • , Yongqi Dong
    •  & Jiangyu Li
  • Article
    | Open Access

    Compared to inorganic materials, the magnetoelectric coupling in macromolecules is still hidden. Here, the authors describe machine learning coupled with additive manufacturing to accelerate the discovery of multiferroic macromolecules with a proton-mediated magnetoelectric coupling effect.

    • Yong Hu
    • , Scott Broderick
    •  & Shenqiang Ren
  • Article
    | Open Access

    The detailed understanding of the structural variations during cycling in cathodes for Zn-ion aqueous rechargeable batteries is still limited. Here, the authors utilize atomic-column-resolved scanning transmission electron microscopy to elucidate multiphase evolution during hydrated Zn-Ion insertion in vanadium oxide.

    • Pilgyu Byeon
    • , Youngjae Hong
    •  & Sung-Yoon Chung
  • Article
    | Open Access

    Ferromagnetic systems rarely display a large or non-saturating magnetoresistance, due to the low Fermi velocity of the predominant charge carrier. Here, the authors show that MnBi, a ferromagnet, bucks this trend, showing both large and non-saturating magnetoresistance, and high charge carrier motilities.

    • Yangkun He
    • , Jacob Gayles
    •  & Claudia Felser
  • Article
    | Open Access

    Switching of ferrimagnets by current-induced spin-orbit torque is promising for spintronics, due to their high-speed dynamics and small macroscopic magnetization. Switching of perpendicularly magnetized materials, however, requires a bias field for symmetry breaking. Here, Zheng et al demonstrate field-free current-induced switching of perpendicular ferrimagnets, using a compositional gradient-driven Dzyaloshinskii–Moriya interaction.

    • Zhenyi Zheng
    • , Yue Zhang
    •  & Pedram Khalili Amiri
  • Article
    | Open Access

    Despite advances in the design of thermally activated delayed fluorescence (TADF) emitters for devices, the effect of spin interactions is not well understood. Here, the authors report the role of spin-vibronic coupling in TADF organic emitters using transient electron spin resonance spectroscopy.

    • Bluebell H. Drummond
    • , Naoya Aizawa
    •  & Emrys W. Evans
  • Article
    | Open Access

    Microcavity exciton-polaritons in atomically thin semiconductors are a promising platform for valley manipulation. Here, the authors show valley-selective control of polariton energies in monolayer WS2 using the optical Stark effect, thereby extending coherent valley manipulation to a hybrid light-matter regime

    • Trevor LaMountain
    • , Jovan Nelson
    •  & Nathaniel P. Stern
  • Article
    | Open Access

    RuCl3 has stood out as a prime candidate in the search for quantum spin liquids; however, its antiferromagnetic ordering at low temperature suggests deviations from typical QSL models. Here, using resonant inelastic x-ray scattering, the authors provide a comprehensive determination of the low energy effective Hamiltonian.

    • H. Suzuki
    • , H. Liu
    •  & B. Keimer
  • Article
    | Open Access

    It was predicted that complex thermalizing behaviour can arise in many-body systems in the absence of disorder. Here, the authors observe non-ergodic dynamics in a tilted optical lattice that is distinct from previously studied regimes, and propose a microscopic mechanism that is due to emergent kinetic constrains.

    • Sebastian Scherg
    • , Thomas Kohlert
    •  & Monika Aidelsburger
  • Article
    | Open Access

    Spin defects in two-dimensional materials potentially offer unique advantages for quantum sensing in terms of sensitivity and functionality. Here, the authors demonstrate the use of spin defects in hexagonal boron nitride as sensors of magnetic field, temperature and pressure, and show that their performance is comparable or exceeds that of existing platforms.

    • Andreas Gottscholl
    • , Matthias Diez
    •  & Vladimir Dyakonov
  • Article
    | Open Access

    Understanding the strange metal behavior, characterized by linear-in-temperature resistivity, could shed light on the mechanism of unconventional superconductivity. Here, by using electrical resistivity measurements into the micro-Kelvin regime, the authors report evidence of unconventional superconductivity in the strange metal YbRh2Si2 and propose a possible pairing mechanism.

    • D. H. Nguyen
    • , A. Sidorenko
    •  & S. Paschen
  • Article
    | Open Access

    The experimental realization of higher order topological insulator (HOTI) in solid state materials remains elusive. Here, Aggarwal et al. reveal hinge states on three edges of both Bi and Bi0.92Sb0.08 (110) islands, supporting them as a class of HOTI.

    • Leena Aggarwal
    • , Penghao Zhu
    •  & Vidya Madhavan
  • Article
    | Open Access

    Nuclear spins in diamond are promising for applications in quantum technologies due to their long coherence times. Here, the authors demonstrate a scalable electrical readout of individual intrinsic 14N nuclear spins in diamond, mediated by hyperfine coupling to electron spin of the NV center, as a step towards room-temperature nanoscale diamond quantum devices.

    • Michal Gulka
    • , Daniel Wirtitsch
    •  & Milos Nesladek
  • Article
    | Open Access

    Thermoelectric effects are limited to electrons to occur, and disappear at low temperatures due to electronic entropy quenching. Here, the authors report thermoelectric generation caused by nuclear spins down to 100 mK due to nuclear-spin excitation in a magnetically ordered material MnCO3.

    • T. Kikkawa
    • , D. Reitz
    •  & E. Saitoh
  • Article
    | Open Access

    Photomutiplication-type organic photodetectors (PM-OPDs) are attractive for various next-generation technologies due to their lower cost, higher sensitivity and technological utility. Here, the authors report vacuum-processed narrowband PM-OPDs with enhanced sub-bandgap external quantum efficiency.

    • Jonas Kublitski
    • , Axel Fischer
    •  & Karl Leo
  • Article
    | Open Access

    Light offers a fast and non-invasive way to generate spin-currents in materials, however, this typically requires special ingredients such as magnetic materials, or circularly polarised light. In this theory work, the authors show how the nonlinear optical effect can generate a spin current, with the only requirement being broken inversion symmetry.

    • Haowei Xu
    • , Hua Wang
    •  & Ju Li
  • Article
    | Open Access

    Advanced screening strategies for the design of high-entropy alloys are highly desirable. Here the authors use the project-oriented design strategy and CALPHAD-based high-throughput calculation tool to rapidly screen promising Al-Cr-Fe-Mn-Ti structural HEAs for high-temperature applications.

    • Rui Feng
    • , Chuan Zhang
    •  & Peter K. Liaw
  • Article
    | Open Access

    Ferroelectricity in orthoferrite perovskites has stimulated intense research, but the mechanism remains unclear. Here, the authors propose an antisite defect mechanism for introducing ferroelectricity in magnetically ordered YFeO3 and the family of rare earth orthoferrites.

    • Shuai Ning
    • , Abinash Kumar
    •  & Caroline A. Ross
  • Article
    | Open Access

    Magnetic Weyl semimetals in the 2D limit may behave like 2D Chern insulators and host the quantum anomalous Hall effect at high temperatures. Here, the authors report the observation of linearly dispersing topological states confined to the edges of the kagome Co3Sn terraces in the magnetic Weyl system Co3Sn2S2.

    • Sean Howard
    • , Lin Jiao
    •  & Vidya Madhavan
  • Article
    | Open Access

    Up-conversion photoluminescence in colloidal quantum dots is generally believed to be mediated by thermal activation from defect states. Here, the authors reveal that highly-efficient up-conversion photoluminescence instead is related to electron-phonon coupling.

    • Zikang Ye
    • , Xing Lin
    •  & Xiaogang Peng
  • Article
    | Open Access

    In real materials, a spin quantum number assumes a fixed value, which makes it challenging to realize a crossover between quantum and classical spin regimes. Here the authors demonstrate such a crossover in a weakly coupled chain compound by controlling the amount of quantum correlations, in the form of the inverse spin quantum number, with external pressure.

    • Daisuke Yamamoto
    • , Takahiro Sakurai
    •  & Yoshiya Uwatoko
  • Article
    | Open Access

    Skyrmions - nanoscale, topological spin textures - are promising elements for next-generation computing due to their efficient coupling to currents in racetrack devices. Here, Tan et al. examine over 20,000 instances of current induced skyrmion motion to unveil a comprehensive picture of skyrmion dynamics across currents and fields.

    • Anthony K. C. Tan
    • , Pin Ho
    •  & Anjan Soumyanarayanan
  • Article
    | Open Access

    It was suggested that the breakdown of the quantum Hall effect in graphene originates from the coupling between counter propagating edge modes. Here, by using scanning gate microscopy, the authors propose a microscopic mechanism of this coupling due to antidots present at graphene edges.

    • N. Moreau
    • , B. Brun
    •  & B. Hackens
  • Article
    | Open Access

    The observation of negative capacitance effect is focused on the ferroelectrics, while the antiferroelectrics based on Landau switches may have negative capacitance effect. Here, the authors report the static and transient negative capacitance effect in antiferroelectric PbZrO3 and reveal its origin.

    • Leilei Qiao
    • , Cheng Song
    •  & Feng Pan
  • Article
    | Open Access

    Laser-assisted electron scattering (LAES) is a commonly observed strong field process in gas phase systems. Here the authors use helium droplets with core atoms and molecules to observe increased electron energy due to multiple LAES events within the droplets.

    • Leonhard Treiber
    • , Bernhard Thaler
    •  & Markus Koch
  • Article
    | Open Access

    Control of the phases associated with the metal-insulator transition in VO2 underpins its applications as a phase change material. Here, the authors report phase management by means of oxide inhibitor-assisted growth and present high-performance VO2 actuators based on asymmetric phase transition routes.

    • Run Shi
    • , Yong Chen
    •  & Chun Cheng
  • Article
    | Open Access

    Single atom magnets on surfaces offer potentially long lived and stable spin states, particular lanthanides, which can be adsorbed onto Magnesium Oxide. Here, the authors report on Dysprosium adsorbed onto Magnesium Oxide, which exhibits large magnetic anisotropy energy, and a spin life time of several days at low temperatures

    • A. Singha
    • , P. Willke
    •  & T. Choi
  • Article
    | Open Access

    In this manuscript, the authors grow very thin layers of FeAs in a matrix of InAs. The resulting superlattice displays ferromagnetism, with the Curie temperature varying depending on the layer thickness. These results further illustrate the wide array of intriguing ground states of materials with tetrahedral FeAs bonds

    • Le Duc Anh
    • , Taiki Hayakawa
    •  & Masaaki Tanaka
  • Article
    | Open Access

    Twist-angle disorder is considered a major source of sample-to-sample variation in magic-angle twisted bilayer graphene. By using scanning tunnelling spectroscopy, the authors demonstrate that a small doping inhomogeneity, present in typical samples, is amplified near the flat band edges and can be another source of disturbance for the flat band physics.

    • Nikhil Tilak
    • , Xinyuan Lai
    •  & Eva Y. Andrei
  • Article
    | Open Access

    Despite the discovery of Majorana zero modes (MZM) in iron-based superconductors, sample inhomogeneity may destroy MZMs during braiding. Here, authors observe MZM in impurity-assisted vortices due to tuning of the bulk Dirac fermions in a homogeneous superconductor LiFeAs.

    • Lingyuan Kong
    • , Lu Cao
    •  & Hong Ding
  • Article
    | Open Access

    Hybrid devices based on electrons on helium may find application in quantum devices. Here the authors demonstrate surface acoustic wave driven acoustoelectric transport of electrons on superfluid helium.

    • H. Byeon
    • , K. Nasyedkin
    •  & J. Pollanen
  • Article
    | Open Access

    Normally the diffusionless solid-to-solid transition between phases are driven by athermal processes, due to strain being overwhelmingly dominant. Here, the authors present a unique series of in-situ particle level observations of the solid-to-solid transition in colloidal particles suspended in a solvent, revealing new transition pathways.

    • Minhuan Li
    • , Zhengyuan Yue
    •  & Peng Tan
  • Article
    | Open Access

    Nuclear spin polarization and relaxation can be studied using nuclear magnetic resonance (NMR). Here the authors demonstrate a combination of fast-field cycling and optical magnetometry techniques, to realize a NMR sensor that operates in the region of very low frequency and high relaxation rate.

    • Sven Bodenstedt
    • , Morgan W. Mitchell
    •  & Michael C. D. Tayler
  • Article
    | Open Access

    The nature of spin interactions and the field-induced quantum spin liquid phase in the Kitaev material α-RuCl3 have been debated. Here, using a combination of many-body techniques, the authors derive an effective spin model that explains the majority of experimental findings and predicts a new quantum spin liquid phase in strong out-of-plane magnetic field.

    • Han Li
    • , Hao-Kai Zhang
    •  & Wei Li
  • Article
    | Open Access

    Although N-heterocyclic carbenes (NHCs) are a promising class of ligands for forming robust self-assembled monolayers on metals, many questions remain about their behavior on surfaces. Here, the authors address these fundamental questions—such as the factors controlling NHC orientation, mobility, and ability to self-assemble—through an in-depth examination of NHC overlayers on Au(111).

    • Alex Inayeh
    • , Ryan R. K. Groome
    •  & Alastair B. McLean
  • Article
    | Open Access

    Recent advances in the identification and growth of antiferromagnetic topological insulators open the way to the manipulation of the chiral edge states that are topologically required at their step edges and domain walls. Here, the authors propose a quantum point junction formed by two types of edge states and discuss its applications in electron quantum optics.

    • Nicodemos Varnava
    • , Justin H. Wilson
    •  & David Vanderbilt
  • Article
    | Open Access

    In all experimentally observed Weyl semimetals so far, the Weyl points always appear in pairs in the momentum space. Here, the authors report one unpaired Weyl point without surface Fermi arc emerging at the center of the Brillouin zone, which is surrounded by charged Weyl nodal walls in PtGa.

    • J.-Z. Ma
    • , Q.-S. Wu
    •  & M. Shi
  • Article
    | Open Access

    The sub-gap absorption coefficient in organic semiconductors is often characterized by Urbach energies, which quantify both structural and dynamic disorders, yet the fundamental is not well-understood. Here, the authors provide a strategy to determine excitonic disorder energy, and reveal that absorption at energies well below the gap is universally dominated by thermal broadening.

    • Christina Kaiser
    • , Oskar J. Sandberg
    •  & Ardalan Armin
  • Article
    | Open Access

    Conductive domain walls have been usually found in ferroelectric oxides. Here, the authors report on giant conductivity of domain walls and their magnetically avalanche-like expulsion event in non-oxide ferroelectric GaV4S8, extending the source of phenomena beyond the realm of oxide electronics.

    • S. Ghara
    • , K. Geirhos
    •  & I. Kézsmárki
  • Article
    | Open Access

    Van der Waals magnetic materials (vdWs) have allowed for the exploration of the two dimensional limit of magnetism, however, most vdWs are only magnetic at low temperature. Herein, the authors overcome this limitation, observing room temperature magnetic ordering in Cobalt doped graphene-like Zinc-Oxide.

    • Rui Chen
    • , Fuchuan Luo
    •  & Jie Yao
  • Article
    | Open Access

    Two possible scenarios of the superconducting order parameter in Sr2RuO4 remain difficult to distinguish. Here, the authors observe that the onset temperature of time reversal symmetry breaking tracks the superconducting transition temperature in Sr2RuO4, supporting a dxz ± idyz order parameter.

    • Vadim Grinenko
    • , Debarchan Das
    •  & Rustem Khasanov
  • Article
    | Open Access

    It was suggested that some 3d materials display bond-dependent exchange interactions, leading to exotic many-body effects. Here, using inelastic neutron scattering, the authors reveal such interactions in the stacked honeycomb magnet CoTiO3 and show how they induce a spectral gap and affect the Dirac magnon band structure.

    • M. Elliot
    • , P. A. McClarty
    •  & R. Coldea