Synthesis of high-entropy hydride from the cantor alloy (fcc-CoCrFeNiMn) at extreme conditions

Glazyrin, K.*; Spektor, K.*; Bykov, M.*; Carvalho, P. H. B.*; Dong, W.*; Krmann, F.*; Sano, Asami; Hattori, Takanori; Beyer, D. C.*; Sahlberg, M.*; et al.

Nature Communications (Internet), 17, p.2622_1 - 2622_10, 2026/03

https://doi.org/10.1038/s41467-026-70483-3

Studies of high entropy materials contribute to various fields of science and reveal ever more exciting properties of applied interest. Here, we perform a study of the resistance of a Cantor alloy (CoCrFeNiMn) to hydrogen through high-pressure experiments at elevated temperatures by X-ray and neutron time-of-flight experiments and ab initio calculations. We report formation of an fcc hydride based on the Cantor alloy composition. We also provide its characterization, including an estimate of hydrogen content. These findings contribute to the growing body of knowledge on the complex chemistry of high-entropy alloys and high-entropy-hydrides.

Magnetic evolution, phase transitions, and electronic band structure of the ferrotoroidic candidate BaCrS

Zhao, G.*; Li, J.*; Zhang, J.*; Kojima, Kenji M*; Cai, Y.*; Ito, Takashi; Yoon, S. W.*; Wang, X.*; Maekawa, Sadamichi*; Su, G.*; et al.

Physical Review Research (Internet), 8(1), p.013331_1 - 013331_10, 2026/03

https://doi.org/10.1103/h576-nnnz

Progress in lattice simulations for two Higgs doublet models

Catumba, G.*; Hiraguchi, Atsuki; Hou, G. W.-S.*; Jansen, K.*; Kao, Y.-J.*; David Lin, C.-J.*; Ramos, A.*; Sarkar, M.*

Proceedings of Science (Internet), 466, p.145_1 - 145_10, 2025/12

https://doi.org/10.22323/1.466.0145

The custodial Two-Higgs-Doublet-Model with SU(2) gauge fields is studied on the lattice. This model has the same global symmetry structure as the Standard Model but the additional Higgs field enlarges the scalar spectrum and opens the possibility for the occurrence of spontaneous symmetry breaking of the global symmetries. Both the spectrum and the running of the gauge coupling of the custodial 2HDM are studied on a line of constant Standard Model physics with cutoff ranging from 300 to 600 GeV. The lower bounds of the realizable masses for the additional BSM scalar states are found to be well bellow the W boson mass. In fact, for the choice of quartic couplings in this work the estimated lower mass for one of the BSM states is found to be about 0.2 and independent of the cutoff.

Lattice investigation of custodial two-Higgs-doublet model at weak quartic couplings

Catumba, G.*; Hiraguchi, Atsuki; Hou, W.-S.*; Jansen, K.*; Kao, Y.-J.*; David Lin, C.-J.*; Ramos, A.*; Sarkar, M.*

Journal of High Energy Physics (Internet), 2025(10), p.214_1 - 214_34, 2025/10

https://doi.org/10.1007/JHEP10(2025)214

The SU(2)-gauged custodial two-Higgs-doublet model, which shares the same global-symmetry properties with the standard model, is studied non-perturbatively on the lattice. The additional Higgs doublet enlarges the scalar spectrum and opens the possibility for spontaneous breaking of the global symmetry. In this work we start by showing the occurrence of spontaneous breaking of the custodial symmetry in a region of the parameter space of the model. Following this, both the spectrum and the running of the gauge coupling are examined at weak quartic couplings in the presence of the custodial symmetry. The calculations are performed with energy cutoffs ranging from 300 to 600 GeV on a line of constant standard model physics, obtained by tuning bare couplings to fix the ratio between the masses of the Higgs and the W bosons, as well as the value of the renormalized gauge coupling at the scale of the W boson mass. The realizable masses for the additional scalar states are explored. For the choice of bare quartic couplings in this work, the estimated lower bound of these masses is found to be well below the W boson mass, and independent of the cutoff. We also study the finite temperature electroweak transition along this line of constant standard model physics, revealing properties of a smooth crossover behavior.

Spin dynamics of triple- magnetic orderings in a triangular lattice; Implications for multi- orderings in general two-dimensional lattices

Park, P.*; Cho, W.*; Kim, C.*; An, Y.*; Iida, Kazuki*; Kajimoto, Ryoichi; Matin, S.*; Zhang, S.-S.*; Batista, C. D.*; Park, J.-G.*

Physical Review X, 15(3), p.031032_1 - 031032_29, 2025/07

https://doi.org/10.1103/y9ly-4kld

Residual stress relaxation of railway gradient S38C steel during fatigue crack growth by neutron imaging and diffraction

Hu, F. F.*; Qin, T. Y.*; Su, Y. H.; He, L. H.*; Ao, N.*; Parker, J. D.*; Shinohara, Takenao; Wu, S. C.*

International Journal of Fatigue, 193, p.108826_1 - 108826_14, 2025/04

https://doi.org/10.1016/j.ijfatigue.2025.108826

Robustness of ferromagnetism in van der Waals magnet FeGeTe to hydrostatic pressure

Wang, Y.*; Zeng, X.-T.*; Li, B.*; Su, C.*; Hattori, Takanori; Sheng, X.-L.*; Jin, W.*

Chinese Physics B, 34(4), p.046203_1 - 046203_6, 2025/03

https://doi.org/10.1088/1674-1056/adb26f

Two-dimensional van der Waals ferromagnet FeGeTe (FGT) holds a great potential for applications in spintronic devices, due to its high Curie temperature, easy tunability, and excellent structural stability in air. In this study, we have performed high-pressure neutron powder diffraction (NPD) up to 5 GPa, to investigate the evolution of its structural and magnetic properties with hydrostatic pressure. The NPD data clearly reveal the robustness of the ferromagnetism in FGT, despite of an apparent suppression by hydrostatic pressure. As the pressure increases from 0 to 5 GPa, the Curie temperature is found to decrease monotonically from 225(5) K to 175(5) K, together with a dramatically suppressed ordered moment of Fe, which is well supported by the first-principles calculations. Although no pressure-driven structural phase transition is observed up to 5 GPa, quantitative analysis on the changes of bond lengths and bond angles indicate a significant modification of the exchange interactions, which accounts for the pressure-induced suppression of the ferromagnetism in FGT.

High-pressure polymerization of phenol toward degree-4 carbon nanothread

Yang, X.*; Che, G.*; Wang, Y.*; Zhang, P.*; Tang, X.*; Lang, P.*; Gao, D.*; Wang, X.*; Wang, Y.*; Hattori, Takanori; et al.

Nano Letters, 25(3), p.1028 - 1035, 2025/01

https://doi.org/10.1021/acs.nanolett.4c04895

Saturated sp-carbon nanothreads (CNTh) have garnered significant interest due to their predicted high Young's modulus and thermal conductivity. While the incorporation of heteroatoms into the central ring has been shown to influence the formation of CNTh and yield chemically homogeneous products, the impact of pendant groups on the polymerization process remains underexplored. In this study, we investigate the pressure-induced polymerization of phenol, revealing two phase transitions occurring below 0.5 and 4 GPa. Above 20 GPa, phenol polymerizes into degree-4 CNThs featuring hydroxyl and carbonyl groups. Hydrogen transfer of hydroxyl groups was found to hinder the formation of degree-6 nanothreads. Our findings highlight the crucial role of the hydroxyl group in halting further intracolumn polymerization and offer valuable insights for future mechanism research and nanomaterial synthesis.

Lattice study of SU(2) gauge theory coupled to four adjoint Higgs fields

Catumba, G.*; Hiraguchi, Atsuki; Hou, W.-S.*; Jansen, K.*; Kao, Y.-J.*; David Lin, C.-J.*; Ramos, A.*; Sarkar, M.*

Physical Review Research (Internet), 6(4), p.043172_1 - 043172_12, 2024/11

https://doi.org/10.1103/PhysRevResearch.6.043172

Gauge theories with matter fields in various representations play an important role in different branches of physics. Recently, it was proposed that several aspects of the interesting pseudogap phase of cuprate superconductors near optimal doping may be explained by an emergent SU(2) gauge symmetry. Around the transition with positive hole-doping, one can construct a (2+1)-dimensional SU(2) gauge theory coupled to four adjoint scalar fields which gives rise to a rich phase diagram with a myriad of phases having different broken symmetries. We study the phase diagram of this model on the Euclidean lattice using the Hybrid Monte Carlo algorithm. We find the existence of multiple broken phases as predicted by previous mean field studies. Depending on the quartic couplings, the SU(2) gauge symmetry is broken down either to U(1) or in the perturbative description of the model. We further study the confinement-deconfinement transition in this theory, and find that both the broken phases are deconfining in the range of volumes that we studied. However, there exists a marked difference in the behavior of the Polyakov loop between the two phases.

Study of 3-dimensional SU(2) gauge theory with adjoint Higgs as a model for cuprate superconductors

Catumba, G.*; Hiraguchi, Atsuki; W.-S. Hou, G.*; Jansen, K.*; Kao, Y.-J.*; David Lin, C.-J.*; Ramos, A.*; Sarkar, M.*

Proceedings of Science (Internet), 453, p.362_1 - 362_7, 2024/11

https://doi.org/10.22323/1.453.0362

We study a 3-dimensional SU(2) gauge theory with 4 Higgs fields which transform under the adjoint representation of the gauge group, that has been recently proposed by Sachdev et al. to explain the physics of cuprate superconductors near optimal doping. The symmetric confining phase of the theory corresponds to the usual Fermi-liquid phase while the broken (Higgs) phase is associated with the interesting pseudogap phase of cuprates. We employ the Hybrid Monte-Carlo algorithm to study the phase diagram of the theory. We find the existence of a variety of broken phases in qualitative accordance with earlier mean-field predictions and discuss their role in cuprates. In addition, we investigate the behavior of Polyakov loop to probe the confinement/deconfinement phase transition, and find that the Higgs phase hosts a stable deconfining phase consistent with previous studies.