Phase transitions and critical phenomena

  • Article
    | Open Access

    While multiband superconductivity is the subject of extensive studies, the possibility of multiband charge density waves (CDW) remains elusive. Here, the authors report evidence of gap opening on both inner and outer bands by a CDW state in 2H-NbSe2, suggesting a possible multiband CDW.

    • Árpád Pásztor
    • , Alessandro Scarfato
    •  & Christoph Renner
  • Article
    | Open Access

    Quasicrystals exhibit long-range order without periodicity. The authors report an approach for quasicrystal fabrication and show through in situ imaging and corresponding simulations the formation of a single decagonal quasicrystal arising from coalescence of multiple quasicrystals in a liquid.

    • Insung Han
    • , Kelly L. Wang
    •  & Ashwin J. Shahani
  • Article
    | Open Access

    Sr3Ru2O7 exhibits a quantum critical point tunable by magnetic field and has been widely used in the study of criticality. Here, by using inelastic neutron scattering, the authors measure collective magnetic excitations near the quantum critical point and relate them to thermodynamic properties and spin density wave order.

    • C. Lester
    • , S. Ramos
    •  & S. M. Hayden
  • Article
    | Open Access

    Strontium Ruthenate, Sr2RuO4, displays a remarkable number of intriguing physical phenomena, from superconductivity, to strain-induced ferromagnetism. Here, using low-energy muon spectroscopy, Fittipaldi et al. demonstrate the existence of unconventional magnetism at the surface of Sr2RuO4 in its normal state and without any applied strain.

    • R. Fittipaldi
    • , R. Hartmann
    •  & A. Di Bernardo
  • Article
    | Open Access

    Strain glass is a new glassy state characterized by frozen ferroelastic nanodomains. Here, the authors discover a low-temperature feature in the specific heat of a strain glass, which is similar to the well-known boson peak anomaly of structural glasses, but cannot be explained by existing mechanisms.

    • Shuai Ren
    • , Hong-Xiang Zong
    •  & Wei-Hua Wang
  • 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

    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

    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

    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

    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

    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

    Whether the electronic nematicity is related to electronic pairing in strongly hole-doped iron-based superconductors remains controversial. Here, the authors perform transport measurements on AFe2As2 (A = K, Rb, Cs) superconductors under elastic strain, and find no indication of a nematic ordered state.

    • P. Wiecki
    • , M. Frachet
    •  & A. E. Böhmer
  • Article
    | Open Access

    In their supercritical state simple fluids are generally thought to assume a homogeneous phase throughout. Lee et al. find that liquid droplets temporarily formed in a supercritical background after sub-critical injection can survive for a surprisingly long time.

    • Seungtaek Lee
    • , Juho Lee
    •  & Gunsu Yun
  • Article
    | Open Access

    The analysis of networks and network processes can require low-dimensional representations, possible for specific structures only. The authors propose a geometric formalism which allows to unfold the mechanisms of dynamical processes propagation in various networks, relevant for control and community detection.

    • Adam Gosztolai
    •  & Alexis Arnaudon
  • 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

    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

    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

    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

    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

    Neuromorphic nanowire networks are found to exhibit neural-like dynamics, including phase transitions and avalanche criticality. Hochstetter and Kuncic et al. show that the dynamical state at the edge-of-chaos is optimal for learning and favours computationally complex information processing tasks.

    • Joel Hochstetter
    • , Ruomin Zhu
    •  & Zdenka Kuncic
  • 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

    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
  • Article
    | Open Access

    Past studies on protein nucleation have focused on the routes that molecules follow towards a crystalline cluster, while possible interactions that may occur between nuclei have not been investigated. Here, the authors show that in the high supersaturation limit such interactions dominate the nucleation process in the form of inter-nucleus docking driving by oriented attachment.

    • Alexander E. S. Van Driessche
    • , Nani Van Gerven
    •  & Mike Sleutel
  • Article
    | Open Access

    Tensor network simulations of lattice gauge theories may overcome the limitations of the Monte Carlo approach, but results have been limited to 1+1 and 2+1 dimensions so far. Here, the authors report a tree-tensor-based numerical study of a 3+1d truncated U(1) lattice gauge theory with fermionic matter.

    • Giuseppe Magnifico
    • , Timo Felser
    •  & Simone Montangero
  • Article
    | Open Access

    The subtle connections between water’s supercooled liquid and glassy states are difficult to characterize. Gartner et al. suggest with MD simulations that the long-range structure of glassy water may reflect signatures of water’s debated second critical point in the supercooled liquid.

    • Thomas E. Gartner III
    • , Salvatore Torquato
    •  & Pablo G. Debenedetti
  • Article
    | Open Access

    Macroscopic properties usually follow algebraic scaling laws near phase transitions. Here, the authors investigate the scaling properties of the metal‐insulator transition at the LaAlO3/SrTiO3 interface, finding that coupling between structural and electronic properties prevents the universal behavior.

    • Eylon Persky
    • , Naor Vardi
    •  & Beena Kalisky
  • Article
    | Open Access

    Ride-sharing, combining similar concurrent trips into one, may support sustainable urban mobility yet lacks broad adoption. Storch et al. reveal how collective interactions in shared rides explain essential characteristics of ride-sharing adoption patterns e.g. observed in New York City and Chicago.

    • David-Maximilian Storch
    • , Marc Timme
    •  & Malte Schröder
  • Article
    | Open Access

    A 3D quantum Hall effect has been reported in Dirac semimetal ZrTe5 due to a magnetic-field-driven Fermi surface instability. Here, the authors show evidence of quasi-quantized Hall response without Fermi surface instability, but they argue that it is due to the interplay of the intrinsic properties of ZrTe5 electronic structure and Dirac semi-metallic character.

    • S. Galeski
    • , T. Ehmcke
    •  & J. Gooth
  • Article
    | Open Access

    Non-Abelian statistics plays a crucial role towards realizing topological quantum computation. Here, the authors discover new types of non-Abelian three-loop braiding statistics that can only be realized in 3D interacting fermionic systems.

    • Jing-Ren Zhou
    • , Qing-Rui Wang
    •  & Zheng-Cheng Gu
  • Article
    | Open Access

    Spinon excitations of a Kagome quantum spin liquid are expected to give rise to a magnetic continuum in Raman spectroscopy. Here, the authors report a magnetic Raman continuum in the Kagome spin liquid candidate Cu3Zn(OH)6FBr, in contrast to a sharp magnon Raman peak in the Kagome antiferromagnet EuCu3(OH)6Cl3.

    • Ying Fu
    • , Miao-Ling Lin
    •  & Jia-Wei Mei
  • Article
    | Open Access

    Previous work on critical scaling at the superconductor-to-insulator transition has shown variations across different materials. Here, the authors use a space charge doping technique to tune the transition in a single layer cuprate sample and present evidence of the universal scaling behaviour.

    • Fang Wang
    • , Johan Biscaras
    •  & Abhay Shukla
  • Article
    | Open Access

    Precise control of vibrational states coupled to electronic degrees of freedom could enable control over charge or magnetic order in a material. Here, the authors use a double-pulse photoexcitation combined with an X-ray probe to control vibrational states near the critical point of spin density wave in Cr films.

    • O. Yu. Gorobtsov
    • , L. Ponet
    •  & A. Singer
  • Article
    | Open Access

    The competition between the formation of different phases and their kinetics need to be clearly understood to make materials with on-demand and multifaceted properties. Here, the authors reveal, by a combination of complementary in situ techniques, the mechanism of a Cu-Zr-Al metallic glass’s high propensity for metastable phase formation, which is partially through a kinetic mechanism of Al partitioning.

    • Jiri Orava
    • , Shanoob Balachandran
    •  & Ivan Kaban
  • Article
    | Open Access

    The Mott transition is a celebrated example of a metal-insulator transition driven by electron correlations. Here, using magnetoresistance measurements, the authors demonstrate the presence of a spin-driven metal-insulator transition, where the insulating gap only opens below the Neel temperature.

    • Yejun Feng
    • , Yishu Wang
    •  & T. F. Rosenbaum
  • Article
    | Open Access

    Domains and domain walls can have distinctively different physical properties. Here, the authors show how to transfer domains into domain walls and vice versa while maintaining their physical properties. Thereby the authors tune a multiferroic state between three and two dimensions.

    • E. Hassanpour
    • , M. C. Weber
    •  & M. Fiebig
  • Article
    | Open Access

    Mixed halide perovskite undergoes halide segregation under illumination, which impairs its functionality as solar cells. Bobbert et al. present a unified thermodynamic theory to explain the phase separation behaviour that takes into account both ground state compositional and electronic part of free energy in the presence of photocarriers.

    • Zehua Chen
    • , Geert Brocks
    •  & Peter A. Bobbert
  • Article
    | Open Access

    Common mitigation measures gradually inhibit the spread of infectious diseases, yielding smooth transitions to large-scale epidemics. As Scarselli et al. show, limited testing may radically change the transition to include jumps, potentially resulting in unforseen, accelerated growth of case numbers.

    • Davide Scarselli
    • , Nazmi Burak Budanur
    •  & Björn Hof
  • Article
    | Open Access

    Chiral superconductors are very rare topological materials. Here, the authors report spontaneous magnetic fields inside the superconducting state and low temperature linear behavior in the superfluid density in LaPt3P, suggesting a chiral d-wave singlet superconducting state.

    • P. K. Biswas
    • , S. K. Ghosh
    •  & M. R. Lees
  • Article
    | Open Access

    The mechanism of the delocalization transition of 4f electrons in closely-packed Ce metal has been debated. Here, the authors present photoemission evidence for bandwidth-controlled Mott delocalization in a previously unreported structural phase of thin epitaxial Ce films obtained by thermal annealing.

    • Yi Wu
    • , Yuan Fang
    •  & Yang Liu
  • Article
    | Open Access

    Photo-induced phase transitions triggered by an ultrafast excitation cannot be described within the quasi-equilibrium framework. Here, using time-resolved experimental probes, the authors report a transient charge-density-wave order in TbTe3 and describe it using a model with a non-equilibrium transition temperature.

    • J. Maklar
    • , Y. W. Windsor
    •  & L. Rettig
  • Article
    | Open Access

    Network robustness is usually assessed following topological criteria, but disregards the role played by non-topological information. Artime et al. propose a flexible percolation framework that overcomes this limitation and combines both dimensions, offering new ways to protect real systems.

    • Oriol Artime
    •  & Manlio De Domenico
  • Article
    | Open Access

    Electric fields and currents can alter microstructures of materials in unexpected ways. Here the authors report how electrochemical reduction can cause a grain boundary disorder-to-order transition and show the electric field effects on microstructural stability and evolution.

    • Jiuyuan Nie
    • , Chongze Hu
    •  & Jian Luo
  • Article
    | Open Access

    Discrete time crystals are typically characterized by a period doubled response with respect to an external drive. Here, the authors predict the emergence of rich dynamical phases with higher-order and fractional periods in clean spin-1/2 chains with long-range interactions.

    • Andrea Pizzi
    • , Johannes Knolle
    •  & Andreas Nunnenkamp
  • Article
    | Open Access

    Tracking the evolution of non-equilibrium phases requires measurements over a wide range of timescales. Here, using a combination of femtosecond spectroscopy and scanning tunneling microscopy, the authors map out a temporal phase diagram of metastable states in a charge-ordered material 1T-TaS2.

    • Jan Ravnik
    • , Michele Diego
    •  & Dragan Mihailovic