Article
Multidisciplinary Sciences
Alexander J. Breindel, Yuhang Deng, Camilla M. Moir, Yuankan Fang, Sheng Ran, Hongbo Lou, Shubin Li, Qiaoshi Zeng, Lei Shu, Christian T. Wolowiec, Ivan K. Schuller, Priscila F. S. Rosa, Zachary Fisk, John Singleton, M. Brian Maple
Summary: This article reports the study of the conductive surface state (CSS) and bulk phase properties of FeSi, and finds that a CSS exists below 19K. Comparison with the Kondo insulator SmB6 reveals similar behavior in magnetoresistance and energy gap changes between the two materials.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Optics
Christian Heide, Yuki Kobayashi, Denitsa R. Baykusheva, Deepti Jain, Jonathan A. Sobota, Makoto Hashimoto, Patrick S. Kirchmann, Seongshik Oh, Tony F. Heinz, David A. Reis, Shambhu Ghimire
Summary: Researchers have found that circularly polarized laser-field-driven high-harmonic generation is highly sensitive to the non-trivial and trivial topological phases in topological insulators. By chemically reducing the spin-orbit interaction strength, the phase transition between non-trivial and trivial topological states can be achieved. This purely optical method offers sensitivity to the electronic structure of the material and is compatible with a wide range of samples and sample environments.
Article
Chemistry, Physical
Yang Song, Wen-Han Dong, Kuan-Rong Hao, Shixuan Du, Lizhi Zhang
Summary: We propose a method to design unconventional magnetic configurations in two-dimensional magnetic materials using d-orbital-based superatomic lattices. By calculating the non-uniform stoichiometries and geometric effects, we found that spin-polarized charges can arrange in different magnetic configurations, leading to nontrivial band topology or strong correlation. This work not only reveals the potential of d-orbital-based superatoms for generating unusual magnetic configurations, but also provides a new avenue for material engineering at the nanoscale.
Article
Multidisciplinary Sciences
Michal Papaj, Cyprian Lewandowski
Summary: Understanding strongly correlated states in flat-band materials is a major focus for both experimental and theoretical research. While various techniques have been successful in studying the properties of the order, the exact nature of the ground state remains unknown. In this study, we propose using strong light-matter coupling in flat-band systems to gain insight into the many-body ground state through dynamical dielectric response. We demonstrate that the plasmon spectrum and dynamical dielectric response are susceptible to the underlying order, providing valuable insights into interaction-driven band gaps, spin structure, and order periodicity.
Article
Materials Science, Multidisciplinary
M. Carlone, J. C. Souza, J. Sichelschmidt, P. F. S. Rosa, R. R. Urbano, P. G. Pagliuso, Z. Fisk, P. A. Venegas, P. Schlottmann, C. Rettori
Summary: This study reports on the temperature dependence of electron spin resonance (ESR) of Gd3+-doped SmB6 single crystals. An anomalous inhomogeneous broadening of the Gd3+ ESR linewidth was observed within a certain temperature range, which is attributed to slow crystalline electric field fluctuations. The observed properties are related to the structure and charge fluctuations of SmB6, providing important insights into its physical properties.
Article
Multidisciplinary Sciences
Yoshiyuki Ohtsubo, Toru Nakaya, Takuto Nakamura, Patrick Le Fevre, Francois Bertran, Fumitoshi Iga, Shin-Ichi Kimura
Summary: The breakdown of in-plane rotation symmetry in topological surface states (TSSs) of SmB6 is shown to be related to the importance of surface atomic structure. Experimentally, it is found that TSSs are anisotropic and lack the fourfold rotation symmetry observed in the bulk on the SmB6(001)-p(2 x 2) surface. These results suggest that engineering the surface atomic structure could provide a new pathway to tailor various properties of TSSs.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
V. V. Glushkov, V. S. Zhurkin, A. D. Bozhko, O. E. Kudryavtsev, B. V. Andryushechkin, N. S. Komarov, V. V. Voronov, N. Yu. Shitsevalova, V. B. Filipov
Summary: The galvanomagnetic characteristics of SmB6 single crystals were studied at different temperatures and crystal faces orientations. The results showed that the surface conductivity in SmB6 is influenced by both the orientation of the surface and the processing method. Etching of polar surfaces led to changes in density and mobility of surface charge carriers.
Article
Chemistry, Multidisciplinary
Hao-Ke Xu, Mingqiang Gu, Fucong Fei, Yi-Sheng Gu, Dang Liu, Qiao-Yan Yu, Sha-Sha Xue, Xu-Hui Ning, Bo Chen, Hangkai Xie, Zhen Zhu, Dandan Guan, Shiyong Wang, Yaoyi Li, Canhua Liu, Qihang Liu, Fengqi Song, Hao Zheng, Jinfeng Jia
Summary: Research has discovered that MnBi4Te7 is a topological insulator with quantum anomalous Hall effect and axion insulator phase. Through scanning tunneling spectroscopy, it has been observed that there is an electronic state at the edge of the magnetic MnBi2Te4 layer at 4.5 K, but not in the nonmagnetic Bi2Te3 layer. As the temperature increases, the edge state disappears, while the state induced by point defects persists.
Article
Physics, Multidisciplinary
Ryan Requist, E. K. U. Gross
Summary: The study focuses on factorizing a many-body wave function in Fock space, describing strongly correlated orbitals and weakly correlated parts separately. By using a generalized Kohn-Sham equation with an orbital-dependent functional approximation, the researchers were able to reproduce the topological phase diagram of a multiband Hubbard model. The roles of band filling and interband fluctuations were also elucidated in the study.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Yugui Cui, Yi Chu, Zhencun Pan, Yingjie Xing, Shaoyun Huang, Hongqi Xu
Summary: This study reports the observation of anisotropic magnetoresistance in a single SmB6 nanowire, showcasing high-symmetry crystal facets and immunity to magnetic dopant pollution. The cosine function behavior of the AMR provides evidence supporting the topologically non-trivial nature of the surface-states by rotation of the in-plane magnetic field.
Article
Physics, Multidisciplinary
Shaowen Chen, Minhao He, Ya-Hui Zhang, Valerie Hsieh, Zaiyao Fei, K. Watanabe, T. Taniguchi, David H. Cobden, Xiaodong Xu, Cory R. Dean, Matthew Yankowitz
Summary: Twisted monolayer-bilayer graphene (tMBG) systems exhibit various correlated metallic and insulating states, as well as topological magnetic states. The phase diagram of tMBG can be switched under different perpendicular electric fields, providing a tunable platform for investigating correlated and topological states.
Article
Chemistry, Physical
Qing Lin He, Taylor L. Hughes, N. Peter Armitage, Yoshinori Tokura, Kang L. Wang
Summary: This Perspective discusses the interplay between magnetism and topology in condensed matter. Topological electronic materials, such as topological insulators, have unique electronic band structures that lead to stable and unconventional topological states, potentially revolutionizing developments in electronics. This Perspective summarizes the advancements of topological insulators in various electronic applications, including spintronics and magnetoelectronics, and analyzes several important phenomena related to topological insulators.
Article
Materials Science, Multidisciplinary
Yadong Jiang, Zhaochen Liu, Jing Wang
Summary: The unoccupied part of the band structure in the magnetic topological insulator MnBi2Te4 has been studied using first-principles calculations. A possible second, unoccupied topological surface state is proposed, which has a similar electronic structure to the occupied topological surface state. Two optical effects are proposed to detect the unoccupied surface state if it exists.
Article
Materials Science, Multidisciplinary
Rui Wang, Z. Y. Xie, Baigeng Wang, Tigran Sedrakyan
Summary: Topological phase transitions involving intrinsic topological orders cannot be described by conventional mean-field theories, but lattice Chern-Simons theory shows that traditional concepts can still play a crucial role in certain cases, while simplifying the transitions to effective mean-field theories based on fermionic degrees of freedom.
Article
Engineering, Electrical & Electronic
Xianzhe Chen, Hua Bai, Yuchen Ji, Yongjian Zhou, Liyang Liao, Yunfeng You, Wenxuan Zhu, Qian Wang, Lei Han, Xiaoyang Liu, Ang Li, Xiaodong Han, Jia Yin, Xufeng Kou, Feng Pan, Cheng Song
Summary: The antiferromagnetic moments in the topological insulator/antiferromagnetic insulator bilayer can be reversibly switched using electrical currents at room temperature, with a critical current density that is one order of magnitude smaller than that in heavy-metal/magnetic insulator systems. This finding has potential applications in building low-power, high-speed memory devices.
NATURE ELECTRONICS
(2022)
Article
Physics, Condensed Matter
A. Azarevich, V Glushkov, S. Demishev, A. Bogach, V. Voronov, S. Gavrilkin, N. Shitsevalova, V Filipov, S. Gabani, J. Kacmarcik, K. Flachbart, N. Sluchanko
Summary: Precise angle-resolved magnetoresistance and magnetization measurements have revealed strong charge transport and magnetic anisotropy, as well as the emergence of multiple magnetic phases in the ground state of isotopically B-11-enriched TmB12 antiferromagnetic metal. The angular H-phi phase diagrams of the antiferromagnetic state were analyzed for the first time and it was proposed that the symmetry lowering is responsible for the appearance of radial phase boundaries between different phases. The Neel field in the (110) plane was found to have significant anisotropy in (TmB12)-B-11 unlike the isotropic AF-P boundary in (HoB12)-B-11.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Physics, Multidisciplinary
A. L. Khoroshilov, A. Bogach, S. Demishev, K. M. Krasikov, S. E. Polovets, N. Yu Shitsevalova, V. B. Filipov, N. E. Sluchanko
Summary: Detailed measurements of the Hall effect in the antiferromagnetic compound Ho0.8Lu0.2B12 were performed in magnetic fields up to 80 kOe. The dominant contribution to the Hall resistance, which results in the double inversion of its sign, was found to be the anisotropic positive contribution. Additionally, a sharp decrease in the amplitude of the isotropic negative contribution at the transition to the antiferromagnetic phase was observed. The anomalies detected in this antiferromagnetic metal with dynamic charge stripes and spin-wave component of the magnetic structure are discussed.
Article
Materials Science, Multidisciplinary
K. M. Krasikov, A. Bogach, S. Demishev, V. V. Voronov, N. Yu Shitsevalova, V. B. Filipov, N. E. Sluchanko
Summary: The study investigates the charge transport and magnetization anisotropy in the antiferromagnetic metal ErB 12 with cooperative Jahn-Teller distortions and electronic instability. It is found that fluctuations of electron density play a crucial role in producing magnetic phase diversity in ErB12.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Physics, Atomic, Molecular & Chemical
S. V. Demishev, A. V. Semeno
Summary: This paper proposes a simple semi-classical model of magnetization dynamics based on Landau-Lifshits equation of motion, which is applied to electron paramagnetic resonance (EPR). The model predicts the polarization effect on the EPR line shape and magnitude due to the orientation of the oscillating magnetization vector, successfully explaining the polarization effect observed in CuGeO3 doped with 2% of Co impurity in EPR mode.
APPLIED MAGNETIC RESONANCE
(2022)
Article
Physics, Multidisciplinary
S. Demishev, A. N. Samarin, M. S. Karasev, S. Grigoriev, A. Semeno
Summary: A study on a manganese monosilicide (MnSi) single crystal using high-frequency electron paramagnetic resonance method reveals the occurrence of spin fluctuation transition and extends the applicability of the concept of spin fluctuation transitions.
Article
Chemistry, Physical
A. V. Gribanov, E. A. Ptashkina, S. F. Dunaev, S. V. Gribanova, M. A. Anisimov, A. V. Bogach, S. V. Demishev, A. V. Semeno
Summary: The crystal structure of a novel CePcl(12)Ge(2) intermetallic compound was determined and refined using single-crystal X-ray diffraction data. The compound exhibits a tetragonal structure of a new type and has a relationship with the known binary compound BaCd11. The magnetic and transport properties of CePd12Ge2 were studied, showing no signs of long-range magnetic ordering below 1.7 K. However, there are hints of magnetic ordering below this temperature based on magnetoresistance data, and a low temperature logarithmic rise in resistivity indicates the important role of Kondo interactions in CePd12Ge2.
Article
Chemistry, Physical
A. V. Semeno, V. N. Krasnorussky, A. V. Bogach, S. V. Demishev, S. V. Gribanova, K. B. Kalmykov, A. V. Gribanov
Summary: We report a new cerium germanide Ce3Pd2Ge7 that exhibits a two-step metamagnetic transition at low temperatures. The transition is associated with two nonequivalent positions of Ce ions in the lattice, and the transition magnitude increases with decreasing temperature.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Biochemistry & Molecular Biology
Artem L. L. Khoroshilov, Kirill M. M. Krasikov, Andrey N. N. Azarevich, Alexey V. V. Bogach, Vladimir V. V. Glushkov, Vladimir N. N. Krasnorussky, Valery V. V. Voronov, Natalya Y. Y. Shitsevalova, Volodymyr B. B. Filipov, Slavomir Gabani, Karol Flachbart, Nikolay E. E. Sluchanko
Summary: The charge transport in the paramagnetic phase of Ho0.8Lu0.2B12 was studied, revealing the existence of an anomalous Hall effect due to the instability of the fcc lattice and the electronic structure. The Hall effect was observed in four mono-domain single crystals of Ho0.8Lu0.2B12 with different crystal axis orientations. An intrinsic anisotropic positive Hall resistivity was found at low temperatures, along with a negative Hall resistivity at high magnetic fields. The anomalies in the resistivity tensor components were explained as the formation of fluctuating charge chains in the structure, with intrinsic and extrinsic mechanisms contributing to the Hall effect. Additionally, a ferromagnetic contribution from magnetic polarization of 5d states was observed in the Hall signal.
Article
Physics, Condensed Matter
Maria Victoria Ale Crivillero, Jean C. Souza, Vicky Hasse, Marcus Schmidt, Natalya Shitsevalova, Slavomir Gabani, Konrad Siemensmeyer, Karol Flachbart, Steffen Wirth
Summary: Scanning Tunneling Microscopy and Spectroscopy (STM/S) is a powerful technique for studying surface states at atomic length scales. This article focuses on the STM/S investigation of two materials, ZrTe2 and TmB4. While ZrTe2 is relatively easy to prepare and study, TmB4 poses significant challenges in obtaining suitable surfaces for analysis. Further efforts are needed to establish a connection between the experimental results and the predicted electronic structure.
Correction
Chemistry, Inorganic & Nuclear
M. Anisimov, V. Voronov, S. Gavrilkin, A. Tsvetkov, K. Mitsen, N. Shitsevalova, G. Levchenko, V. Filipov, S. Demishev, V. Glushkov
SOLID STATE SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Zuzana Pribulova, Miroslav Marcin, Jozef Kacmarcik, Slavomir Gabani, Karol Flachbart, Natalya Shitsevalova, Takao Mori, Nikolay Sluchanko, Mikhail Anisimov, Vladimir Cambel, Jan Soltys, Christophe Marcenat, Thierry Klein, Peter Samuely
Summary: By using an array of miniature Hall probes, the penetration of the magnetic field, pinning, and critical current density on a series of YB6 single crystals with different superconducting transition temperatures has been studied. The stoichiometry and transition temperature were determined by analyzing the specific heat characteristics. It was found that the increase in vacancies leads to enhanced pinning and critical current density, consistent with weak collective pinning theory.
JOURNAL OF PHYSICS-MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Julius Backai, Slavomir Gabani, Gabriel Pristas, Matus Orendac, Emil Gazo, Kirill Krasikov, Nikolay Sluchanko, Konrad Siemensmeyer, Natalya Shitsevalova, Karol Flachbart
Summary: Precise angle-resolved magnetoresistance (ARMR) measurements in TmB4 reveal the anisotropic charge transport and magnetic structure of this strongly Ising anisotropic quantum antiferromagnet. Ap/p(v,H) distributions show that the main magnetoresistance features appear along the easy axis of magnetic anisotropy and are related to magnetic phases and phase transitions. ARMR is a sensitive tool for studying the interplay between charge carriers and magnetic structure.
Article
Mechanics
S. V. Demishev
Summary: Experimental data on low-temperature (T < 40 K) neutron scattering and electron paramagnetic resonance for a helical magnet MnSi are analyzed. The presence of spin-fluctuation transitions (SFTs) disrupts the smooth evolution of spin fluctuation parameters in the conventional theory of magnetic phase transitions and its generalization to the case of helical magnets. Precursor spin-fluctuation transitions are observed before the transition to a helical magnetically ordered phase, with temperatures T1 = 32 K and T2 = 30.5 K preceding Tc = 29 K. Another spin-fluctuation transition with parameters characteristic for the SFT inside the magnetically ordered phase is discovered at a temperature of 29 K under a magnetic field of B similar to 2 T. It is shown that the appearance of helical fluctuations occurs at T = T1, while the appearance of a helical phase (B = 0) or a spin-polarized phase (B = 2 T) at T = T2 is accompanied by a spin-fluctuation transition.
Article
Materials Science, Multidisciplinary
N. B. Bolotina, O. N. Khrykina, A. N. Azarevich, N. Yu Shitsevalova, V. B. Filipov, S. Yu Gavrilkin, K. Mitsen, V. V. Voronov, N. E. Sluchanko
Summary: Inhomogeneous superconductivity in ZrB12 was studied using heat capacity and x-ray diffraction data. Evidence of two-gap superconductivity was found when a magnetic field was applied along the [110] axis, while a single gap was observed when the magnetic field was applied along the [100] axis. These findings are consistent with the checkerboard-type patterns observed in the electron density distribution.