Physics

  • Article
    | Open Access

    The honeycomb lattice with a spin-orbit interaction can give rise to exotic quantum states. With the measurements of bulk properties and inelastic neutron scattering, Lin et al demonstrate the existence of a field induced spin-disordered state in Na2Co2TeO6 and extend the Kitaev model to 3d system.

    • Gaoting Lin
    • , Jaehong Jeong
    •  & Jie Ma
  • Article
    | Open Access

    Cherenkov detectors are used to detect high energy particles and their performance capabilities depend heavily on the material used. Here, the authors propose use of a Brewster-optics-based angular filter for a detector with increased sensitivity and particle identification capability.

    • Xiao Lin
    • , Hao Hu
    •  & Yu Luo
  • Article
    | Open Access

    Graphene nanoribbons are potential systems for engineering topological phases of matter, but the pre-required gapped phases are difficult to find. Here, the authors show that chiral graphene nanoribbons undergo a transition from metallic to topological insulators, and then to trivial band insulators as they are narrowed down to nanometer widths.

    • Jingcheng Li
    • , Sofia Sanz
    •  & Jose Ignacio Pascual
  • Article
    | Open Access

    The awareness of rock shape dependence in rockfall hazard assessment is growing, but experimental and field studies are scarce. This study presents a large data set of induced single block rockfall events quantifying the influence of rock shape and mass on its complex kinematic behaviour.

    • Andrin Caviezel
    • , Adrian Ringenbach
    •  & Perry Bartelt
  • Article
    | Open Access

    Resistive switching usually occurs by the formation of conducting filaments in the direction of current flow. Here the authors study an intriguing type of volatile metal-to-insulator resistive switching in (La,Sr)MnO3, which occurs by the formation of an insulating barrier perpendicular to the current.

    • Pavel Salev
    • , Lorenzo Fratino
    •  & Ivan K. Schuller
  • Article
    | Open Access

    Here, the authors report on evidence of an excitonic species formed by electrons in high-energy conduction band states with a negative effective mass, explaining previous observations of quantum interference phenomena in two-dimensional semiconductors.

    • Kai-Qiang Lin
    • , Chin Shen Ong
    •  & John M. Lupton
  • Article
    | Open Access

    Valley anisotropy is proposed theoretically to benefit the electrical transport of thermoelectric materials but it lacks experimental demonstration. Here, the authors demonstrate how to utilize the single anisotropic Fermi pocket in p-type Mg3Sb2 to enhance its thermoelectric properties.

    • Airan Li
    • , Chaoliang Hu
    •  & Tiejun Zhu
  • Article
    | Open Access

    Magic-angle twisted bilayer graphene exhibits a quantum anomalous Hall effect at 3/4 filling; however, its mechanism is debated. Here, the authors show that such a phase can be realized in a lattice model of twisted bilayer graphene in the strong coupling limit, and interpret the results in terms of a topological Mott insulator phase.

    • Bin-Bin Chen
    • , Yuan Da Liao
    •  & Zi Yang Meng
  • Article
    | Open Access

    Strong light-matter coupling has been realized at the level of single atoms and photons throughout most of the electromagnetic spectrum, except for the THz range. Here, the authors report a THz-scale transport gap, induced by vacuum fluctuations in carbon nanotube quantum dot through the deep strong coupling of a single electron to a THz resonator.

    • F. Valmorra
    • , K. Yoshida
    •  & T. Kontos
  • Article
    | Open Access

    Several hydrides have been observed high-Tc superconductivity under pressure, but a physical-chemical understanding of the properties enhancing Tc is still lacking. Here, the authors propose a magnitude named as networking value, combined with hydrogen fraction and the contribution of hydrogen to the density of states at Fermi level, can predict Tc of all hydrogen-based compounds with an accuracy of about 60 K.

    • Francesco Belli
    • , Trinidad Novoa
    •  & Ion Errea
  • Article
    | Open Access

    Transition metal kagome compounds have been shown to host flat bands in their bulk electronic spectrum. Here, using planar tunnelling spectroscopy supported by first-principles calculations, the authors report the signature of a novel type of flat band at the surface of antiferromagnetic kagome metal FeSn.

    • Minyong Han
    • , Hisashi Inoue
    •  & Joseph G. Checkelsky
  • Article
    | Open Access

    The development of fast and dynamic topological photonic platforms is an ongoing challenge. Here, the authors demonstrate a reprogrammable plasmonic topological insulator in which ultrafast electric switches allow for nanosecond-level switching time between different configurations.

    • Jian Wei You
    • , Qian Ma
    •  & Tie Jun Cui
  • Article
    | Open Access

    Optical excitation of transition metal dichalcogenide monolayers mostly generates excitons species with inherently short lifetime and spin/valley relaxation time. Here, the authors demonstrate efficient spin/valley optical pumping of resident electrons in n-doped WSe2 and WS2 monolayers.

    • Cedric Robert
    • , Sangjun Park
    •  & Xavier Marie
  • Article
    | Open Access

    Ultrafast diffraction is fundamental in capturing the structural dynamics of molecules. Here, the authors establish a variant of quantum state tomography for arbitrary degrees of freedom to characterize the molecular quantum states, which will enable the reconstruction of a quantum molecular movie from diffraction data.

    • Ming Zhang
    • , Shuqiao Zhang
    •  & Zheng Li
  • Article
    | Open Access

    Superconductivity in FeSe attracted great interests to understand the mechanism of high temperature superconductivity. Here, the authors report a pressure induced superconductivity with a highest Tc of ~9 K in MnSe.

    • T. L. Hung
    • , C. H. Huang
    •  & T. K. Lee
  • Article
    | Open Access

    Atomic monolayers of large-gap quantum spin Hall insulators are challenging to synthesize. Here, the authors realize massive Dirac fermions emerging from Bloch wave-function interference on a triangular lattice and achieve topologically non-trivial domains with unprecedented spatial extension.

    • Maximilian Bauernfeind
    • , Jonas Erhardt
    •  & Giorgio Sangiovanni
  • Article
    | Open Access

    Though non-Hermitian physics has contributed toward the advance of research in quantum, electronic and classical systems, previous work focused on zero- or one-dimensional systems. Here, the authors report higher-order non-Hermitian skin effects in a 2D acoustic higher-order topological insulator.

    • Xiujuan Zhang
    • , Yuan Tian
    •  & Yan-Feng Chen
  • Article
    | Open Access

    Room-temperature exciton polaritons in a monolayer WS2 are shown to display strong motional narrowing of the linewidth and enhanced first-order coherence. They can propagate for tens of micrometers while maintaining partial coherence, and display signatures of ballistic (dissipationless) transport.

    • M. Wurdack
    • , E. Estrecho
    •  & E. A. Ostrovskaya
  • Article
    | Open Access

    Toroidal moments arise from vortex like spin arrangements. These moments can then interact, giving rise to ferri- or ferro-toroidal order, though controlling such order is difficult. Here, the authors demonstrate a ferri-toroidal state in BaCoSiO4, which under an applied magnetic field exhibits multiple toroidal and metamagnetic transitions.

    • Lei Ding
    • , Xianghan Xu
    •  & Huibo Cao
  • Article
    | Open Access

    Van der Waals structures provide a new platform to explore novel physics of superconductor/ferromagnet interfaces. Here, NbSe2 Josephson junction with Cr2Ge2Te6 enables non-trivial Josephson phase by spin-dependent interaction, boosting the study of superconducting states with spin-orbit coupling and phase-controlled quantum electronic device.

    • H. Idzuchi
    • , F. Pientka
    •  & P. Kim
  • Article
    | Open Access

    Anisotropic spin S >1/2 quantum magnets can have multiple low energy modes. In this manuscript, the authors study the interaction of such low energy modes in the S = 1 antiferromagnet Ba2FeSi2O7 by combining neutron scattering measurements with an SU(3) generalization of the 1/S expansion.

    • Seung-Hwan Do
    • , Hao Zhang
    •  & Andrew D. Christianson
  • Article
    | Open Access

    Conventional quantum particles can break up into fractionalized excitations under the right conditions; however, their direct experimental observation is challenging. Here, the authors predict strong optical conductivity signatures of such excitations in the vicinity of a topological phase transition.

    • Yan-Cheng Wang
    • , Meng Cheng
    •  & Zi Yang Meng
  • Article
    | Open Access

    Previous work has shown that helical domain walls can form between states of different spin-polarization during a ferromagnetic spin transition in the fractional quantum Hall regime. Here, the authors study the transport through a single helical domain wall and find strong deviations from a simplified theory of weakly interacting edge channels.

    • Ying Wang
    • , Vadim Ponomarenko
    •  & Leonid P. Rokhinson
  • Article
    | Open Access

    Skyrmions are topological two-dimensional spin textures that in three-dimensional systems resemble strings or tubes. Here, using transmission electron microscopy Zheng et al observe the braiding of skyrmion strings in FeGe and predict this phenomenon for a large family of magnets.

    • Fengshan Zheng
    • , Filipp N. Rybakov
    •  & Rafal E. Dunin-Borkowski
  • Article
    | Open Access

    Phase transition brings a plethora of exotic phenomena and intriguing effects such as spin and charge frustration. However, the phase transition order is not always explicit. Here, the authors discover phase transition frustration near a tricritical composition point in ferroelectric Pb(Zr,Ti)O3.

    • Xian-Kui Wei
    • , Sergei Prokhorenko
    •  & Zuo-Guang Ye
  • Article
    | Open Access

    The nonequilibrium regime provides an exciting frontier in the search for novel quantum phases of matter. Here, the authors show that optically driving a lightly-doped semiconductor can lead to the spontaneous formation of a dynamical quantum liquid crystalline phase with a rotating magnetization.

    • Iliya Esin
    • , Gaurav Kumar Gupta
    •  & Netanel H. Lindner
  • Article
    | Open Access

    Mn3Sn is an anti-ferromagnetic material which displays a large magneto-optical Kerr effect, despite lacking a ferromagnetic moment. Here, the authors show that likewise, Mn3Sn, also presents a particularly large magneto-optical Voigt signal, with a negligible change in the quench time over a wide temperature range.

    • H. C. Zhao
    • , H. Xia
    •  & H. B. Zhao
  • Article
    | Open Access

    Quantized response has so far eluded classical system beyond linear response theory. Here, the authors predict that a quantized classical response, arising from fundamental mathematical properties of the Green’s function, shows up in steady-state response of a non-Hermitian system without invoking a linear response theory.

    • Linhu Li
    • , Sen Mu
    •  & Jiangbin Gong
  • Article
    | Open Access

    Multistep nucleation phenomena are of considerable fundamental interest. Here the authors combine molecular dynamics, machine learning and molecular cluster analysis to investigate the multistep nucleation of smectic clusters from a nematic fluid that cannot be accounted for by the classical nucleation theory.

    • Kazuaki Z. Takahashi
    • , Takeshi Aoyagi
    •  & Jun-ichi Fukuda
  • Article
    | Open Access

    Free carriers and electrical polarization coexist in ferroelectric metals. Here, the authors use a capacitive method to probe the electronic compressibility of free carriers in a tunable semimetal, extract the polarized contribution, and study the carrier dependence of the ferroelectric state.

    • Sergio C. de la Barrera
    • , Qingrui Cao
    •  & Benjamin M. Hunt
  • Article
    | Open Access

    It was predicted that in the regime of strong electron-phonon interactions, electrons and phonons can form a coupled non-equilibrium state, characterized by the conservation of the total momentum and by hydrodynamic transport. Here, the authors report experimental evidence for such a coupled electron-phonon liquid in NbGe2.

    • Hung-Yu Yang
    • , Xiaohan Yao
    •  & Fazel Tafti
  • Article
    | Open Access

    N00N states are a key resource in quantum metrology, but the use of their multi-mode extension for multiparameter estimation has been elusive so far. Here, the authors use multi-mode N00N states - with N=2 photons in 4 modes - for multiple-phase estimation saturating the quantum Cramer-Rao bound.

    • Seongjin Hong
    • , Junaid ur Rehman
    •  & Hyang-Tag Lim
  • Article
    | Open Access

    Shock-wave driven reactions of organic molecules may have played a key role in prebiotic chemistry, but their mechanisms are difficult to investigate. The authors, using time-resolved x-ray diffraction and small-angle x-ray scattering experiments, observe the transformation of liquid benzene during a shock, identifying carbon and hydrocarbon solid products.

    • D. M. Dattelbaum
    • , E. B. Watkins
    •  & R. L. Sandberg
  • Article
    | Open Access

    Triplons are elementary spin excitations characteristic of dimerized magnets, carrying a spin angular momentum one. Here, the authors report evidence for spin current of triplons via thermal transport measurements in a spin-dimer compound CuGeO3.

    • Yao Chen
    • , Masahiro Sato
    •  & Eiji Saitoh
  • Article
    | Open Access

    Network dismantling allows to find minimum set of units attacking which leads to system’s break down. Grassia et al. propose a deep-learning framework for dismantling of large networks which can be used to quantify the vulnerability of networks and detect early-warning signals of their collapse.

    • Marco Grassia
    • , Manlio De Domenico
    •  & Giuseppe Mangioni
  • Article
    | Open Access

    So far, experimental results have favoured the often unstated assumption that quantum statistical properties of multiparticle systems are preserved in plasmonic platforms. Here, the authors show how multiparticle interference in photon-plasmon scattering can modify the excitation mode of plasmonic systems.

    • Chenglong You
    • , Mingyuan Hong
    •  & Omar S. Magaña-Loaiza
  • Article
    | Open Access

    Quantifying dimensionality of high-dimensional entangled states is challenging, especially in the presence of mixedness and noise. Here, the authors propose and demonstrate a method to quantify the dimensionality and purity of a bi-photon HD entangled state, scaling linearly with entanglement dimension.

    • Isaac Nape
    • , Valeria Rodríguez-Fajardo
    •  & Andrew Forbes
  • Article
    | Open Access

    Efficient conversion of microwave photons into electrical current would enable several applications in quantum technologies, especially if one could step outside of the gated-time regime. Here, the authors demonstrate continuous-time microwave photoconversion in double quantum dots with 6% efficiency.

    • Waqar Khan
    • , Patrick P. Potts
    •  & Ville F. Maisi
  • Article
    | Open Access

    In FeRh, it is possible to optically drive a phase transition between ferromagnetic (FM) and anti-ferromagnetic (AFM) ordering. Here, using a combination of photoelectron spectroscopy and ab-initio calculations, the authors demonstrate the existence of a transient intermediate phase, explaining the delayed appearance of the FM phase.

    • Federico Pressacco
    • , Davide Sangalli
    •  & Fausto Sirotti
  • Article
    | Open Access

    The question whether a given isolated quantum many-body system would thermalize has currently no general answer. Here, Shiraishi and Matsumoto demonstrate the computational universality of thermalization phenomena already for simplified 1D systems, thus proving that the thermalization problem is undecidable.

    • Naoto Shiraishi
    •  & Keiji Matsumoto
  • Article
    | Open Access

    Balances for nanoparticles such as resonating fluid-filled cantilevers usually probe only mass through changes in oscillation frequency. Katsikis and Collis et al. tap information from previously ignored rotational motion to simultaneously measure particle mass and volume.

    • Georgios Katsikis
    • , Jesse F. Collis
    •  & Scott R. Manalis
  • Article
    | Open Access

    Skyrmions are a type of topological spin texture that great potential across a wide variety of technological applications. Here, Yu et al. study the thermally driven motion of Skyrmions and find a minimum temperature gradient for the motion of skyrmions two orders of magnitude smaller than for domain walls.

    • Xiuzhen Yu
    • , Fumitaka Kagawa
    •  & Yoshinori Tokura
  • Article
    | Open Access

    Additives have been widely used for passivating defects in perovskite semiconductors, yet the role of additive and their interaction is not clear. Here, the authors reveal an additive-assisted crystal formation in FAPbI3 perovskite by tracking the chemical interaction in the precursor solution and crystallographic evolution using multi-functional additives.

    • Lin Zhu
    • , Hui Cao
    •  & Jianpu Wang
  • Article
    | Open Access

    The discovery of high temperature superconductivity in hydrogen-rich compounds stimulates further extensive studies. Here, the authors report superconductivity in pressurized yttrium-hydrogen system with highest predicted Tc among binary compounds.

    • Panpan Kong
    • , Vasily S. Minkov
    •  & Mikhail I. Eremets