Article
Materials Science, Multidisciplinary
Tommaso Gorni, Diego Florez-Ablan, Luca de'Medici
Summary: In this study, we calculate the electronic properties of the normal state of uncollapsed LaFe2As2, considering local dynamical correlations. Our results show that LaFe2As2 has a reduced bare bandwidth, which explains the substantial correlations despite its nominal valence d6.5.
Article
Materials Science, Multidisciplinary
Li Xiang, Mingyu Xu, Sergey L. Bud'ko, Paul C. Canfield
Summary: Resistance measurements were performed on single crystals of CaK(Fe1-xMnx)4As4 (x = 0.024) under hydrostatic pressure. The pressure dependence of the magnetic and superconducting transition temperatures, as well as the superconducting upper critical field, was investigated. The results show that the magnetic transition temperature is suppressed with increasing pressure, while the superconducting transition temperature initially increases and then decreases, reaching a maximum at a specific pressure. Furthermore, changes in the pressure dependence of the superconducting coherence length were observed at this pressure.
Article
Materials Science, Multidisciplinary
H. Pfau, M. Yi, M. Hashimoto, T. Chen, P-C Dai, Z-X Shen, S-K Mo, D. Lu
Summary: The study investigates the influence of electronic nematicity on quasiparticle coherence in detwinned FeSe using ARPES, finding an anisotropy between dxz and dyz orbitals and a more coherent dxz orbital compared to the dyz orbital. This observation contrasts with earlier predictions and underscores the importance of electronic correlations in describing nematicity.
Article
Materials Science, Multidisciplinary
Jianzhou Zhao, Yilin Wang, Xiaolong Feng, Shengyuan A. Yang
Summary: By comparing the electronic structures of LaFe2As2 and CaFe2As2, researchers found that they are similar in terms of electronic correlation and Fermi-surface topology, suggesting that superconductivity may also be induced in the collapsed phase of LaFe2As2 under similar conditions as for CaFe2As2.
Article
Chemistry, Physical
Leonid Morgun, Svetoslav Kuzmichev, Igor Morozov, Alena Degtyarenko, Andrey Sadakov, Andrey Shilov, Ilya Zhuvagin, Yevgeny Rakhmanov, Tatiana Kuzmicheva
Summary: A comprehensive study of the superconducting properties of underdoped NaFe0.979Co0.021As single crystals is presented, using a combination of upper critical field measurements and incoherent multiple Andreev reflection effect (IMARE) spectroscopy. The study reveals the temperature dependence of the Hc2(T) and the characteristics of the superconducting order parameters.
Article
Physics, Multidisciplinary
Hualei Sun, Liang Qiu, Yifeng Han, Yunwei Zhang, Weiliang Wang, Chaoxin Huang, Naitian Liu, Mengwu Huo, Lisi Li, Hui Liu, Zengjia Liu, Peng Cheng, Hongxia Zhang, Hongliang Wang, Lijie Hao, Man-Rong Li, Dao-Xin Yao, Yusheng Hou, Pengcheng Dai, Meng Wang
Summary: Understanding the interplay between superconductivity and magnetism in EuTe2 is achieved through high pressure studies. A structural transition and superconductivity are observed at different pressures. Strong couplings between local moments and conduction electrons are observed in the low-pressure phase, while the high-pressure phase loses magnetism and has a lower upper critical field.
COMMUNICATIONS PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Yong Zhang, Fucong Fei, Ruxin Liu, Tongshuai Zhu, Bo Chen, Tianyu Qiu, Zewen Zuo, Jingwen Guo, Wenchao Tang, Lifan Zhou, Xiaoxiang Xi, Xiaoshan Wu, Di Wu, Zhicheng Zhong, Fengqi Song, Rong Zhang, Xuefeng Wang
Summary: By studying Ta-doped Mo1-xTaxTe2 single crystals, it is found that Ta doping can significantly enhance the superconductivity, with a transition temperature of up to 7.5 K. An enhanced perpendicular upper critical field of 14.5 T exceeding the Pauli limit is also observed, indicating the possible emergence of unconventional mixed singlet-triplet superconductivity and inversion symmetry breaking.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Mehdi Hesani, Kourosh Rahimi, Ahmad Yazdani
Summary: The study investigated the relationship between charge doping and correlations in BaFe2As2 using DFT+DMFT, showing that electronic correlations strengthen systematically from electron-doping to hole-doping regimes. Due to its multi-orbital nature, correlations in BaFe2As2 are orbital-dependent, with the Fe-3d(xy) orbital exhibiting the most correlation.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
H. Su, T. Shang, F. Du, C. F. Chen, H. Q. Ye, X. Lu, C. Cao, M. Smidman, H. Q. Yuan
Summary: NbReSi is a noncentrosymmetric material that exhibits fully gapped superconducting state with a large upper critical field dominated by Re and Nb d orbitals. The discovery of superconductivity in NbReSi sheds light on the puzzle of time-reversal symmetry breaking observed in some Re-based superconductors.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Multidisciplinary Sciences
Ye Yang, Fanghang Yu, Xikai Wen, Zhigang Gui, Yuqing Zhang, Fangyang Zhan, Rui Wang, Jianjun Ying, Xianhui Chen
Summary: Based on electrical transport and XRD measurements, as well as first-principles calculations, researchers discover a unique pressure-induced Mott transition from an antiferromagnetic Mott insulator to a ferromagnetic Weyl metal in the iron oxychalcogenide La2O3Fe2Se2 around 37 GPa without any structural change. The theoretical calculations indicate that this insulator-metal transition is mainly due to the increased bandwidth and reduced electron correlation under high pressure. Moreover, the high-pressure ferromagnetic Weyl metallic phase exhibits attractive electronic band structures with six pairs of Weyl points near the Fermi level, which can be easily manipulated by a magnetic field.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Michael Jurkutat, Carsten Kattinger, Stefan Tsankov, Richard Reznicek, Andreas Erb, Juergen Haase
Summary: High-temperature superconducting cuprates exhibit a dome-like dependence of their critical temperature (Tc) with doping, but this maximum Tc can be enhanced by applying pressure, a well-known observation for decades. In this study, we used high-pressure anvil cell NMR to investigate this phenomenon and found that pressure increases overall hole doping and leads to a redistribution of holes favoring planar O, similar to the observation of higher maximum Tc for materials with higher hole content at planar O. These results indicate that the pressure-induced enhancement of the maximum Tc points to the same mechanism.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Materials Science, Multidisciplinary
C. Trainer, M. Songvilay, N. Qureshi, A. Stunault, C. M. Yim, E. E. Rodriguez, C. Heil, V Tsurkan, M. A. Green, A. Loidl, P. Wahl, C. Stock
Summary: Fe1+xTe is a two-dimensional van der Waals antiferromagnet that becomes superconducting with anion substitution on the Te site. The bulk magnetic structure of Fe1+xTe shows collinear in-plane order, while the surface exhibits a magnetic surface reconstruction with a canting angle of the spins. This difference in magnetic properties between the bulk and surface of Fe1+xTe suggests that surface structural relaxation leads to an out-of-plane magnetocrystalline anisotropy.
Article
Materials Science, Multidisciplinary
Laura Fanfarillo, Angelo Valli, Massimo Capone
Summary: We demonstrate that the experimental manifestations of nematic order in iron-based superconductors are intrinsically related to electronic correlations in the Hund's correlated metallic state, and cannot be explained using a renormalized quasiparticle picture. Specifically, we find that (i) in a metal where correlations are dominated by the Hund's coupling, nematic ordering does not result in a rigid energy shift in the photoemission spectra, but rather a more complex spectral weight redistribution that reflects the experimental observations, and (ii) the nematic ordering exhibits orbital-selective coherence induced by Hund's physics, consistent with experimental observations.
Article
Nanoscience & Nanotechnology
Guorui Xiao, Wuzhang Yang, Qinqing Zhu, Shijie Song, Guang-Han Cao, Zhi Ren
Summary: A series of new Cr5+xMo35xW12Re35Ru13C20 high-entropy alloys have been synthesized and characterized, showing bulk superconductivity. The lattice parameter and superconducting transition temperature vary with different compositions.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Multidisciplinary
Armando Galluzzi, Antonio Leo, Andrea Masi, Francesca Varsano, Angela Nigro, Gaia Grimaldi, Massimiliano Polichetti
Summary: This study focuses on the vortex phase diagram of CaKFe4As4, which is helpful for understanding the applicative ranges in field and temperature of these materials. Different magnetic measurements were performed to draw a complete vortex phase diagram for a CaKFe4As4 polycrystalline iron-based superconductor, revealing a second magnetization peak effect and a transition in the vortex lattice from elastic to plastic behavior.
APPLIED SCIENCES-BASEL
(2023)
Article
Materials Science, Multidisciplinary
Taichi Terashima, Shinya Uji, Teng Wang, Gang Mu
Summary: This study reports the phenomenon that the quantum-oscillation frequencies exhibit a negative shift, which can be utilized to identify Dirac/Weyl fermions, but there is a deviation between experimental results and theoretical predictions at lower temperatures.
NPJ QUANTUM MATERIALS
(2022)
Article
Physics, Applied
Yuta Kobayashi, Motoi Kimata, Daisuke Kan, Tetsuya Ikebuchi, Yoichi Shiota, Hiroshi Kohno, Yuichi Shimakawa, Teruo Ono, Takahiro Moriyama
Summary: This study investigates the relationship between anomalous Hall conductivity and the chemical order parameter in chiral antiferromagnetic L1(2)-Mn3Ir (111)-oriented films. The results show that the anomalous Hall conductivity is more pronounced in (111)-oriented films compared to (001)-oriented films, consistent with the theoretical prediction. It is also found that the anomalous Hall conductivity strongly depends on the longitudinal conductivity, suggesting a possible extrinsic contribution.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Multidisciplinary
Shinya Uji, Taichi Terashima, Daigorou Hirai, Takahito Anbai, Zenji Hiroi
Summary: Magnetic torque measurements were conducted to investigate the electronic state of metallic beta-phase ReO2 with Dirac nodal lines forming a loop chain. The experimental results showed sinusoidal torque curves with a two-fold symmetry throughout the entire temperature range. As the temperature decreased, a significant nonlinear magnetization effect was observed, especially for the magnetic field in the ac plane. Analysis based on Landau theory revealed that this change in torque signal was attributed to electric quadrupole fluctuations. Furthermore, the study found a strongly enhanced anisotropic susceptibility due to quadrupole fluctuations near 0K and 0T, suggesting the presence of quantum critical behavior.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2022)
Article
Materials Science, Multidisciplinary
Taichi Terashima, Hishiro T. Hirose, Naoki Kikugawa, Shinya Uji, David Graf, Takao Morinari, Teng Wang, Gang Mu
Summary: In this study, the resistivity and conductivity were measured in CaFeAsF, and the emergence of the nu = 0 quantum Hall state was observed under high magnetic field strengths.
NPJ QUANTUM MATERIALS
(2022)
Article
Chemistry, Inorganic & Nuclear
Naoki Kikugawa, Taichi Terashima, Takashi Kato, Momoko Hayashi, Hitoshi Yamaguchi, Shinya Uji
Summary: In this study, single crystals of a magnetic Weyl semimetal candidate NdAlGe were successfully grown using a floating-zone technique with laser diodes as the heat source. The crystals showed magnetic order at 13.5 K and were characterized for their physical properties using various measurements. The study revealed the anisotropic magnetoelasticity, magneto-entropy, and charge transport induced by the magnetic order in NdAlGe.
Article
Physics, Multidisciplinary
H. Sakai, Y. Tokiwa, P. Opletal, M. Kimata, S. Awaji, T. Sasaki, D. Aoki, S. Kambe, Y. Tokunaga, Y. Haga
Summary: The superconducting phase diagram in uranium ditelluride was investigated using high-quality single crystals under magnetic fields along the hard magnetic b axis. Low-field and high-field superconducting phases with different field-angular dependence were distinguished through electrical resistivity and ac magnetic susceptibility measurements. The crystal quality affected the upper critical field of the low-field superconducting phase, but the H* value at which the high-field superconducting phase appeared remained the same across different crystals. A phase boundary signature was also observed inside the low-field superconducting phase near H*, indicating the presence of an intermediate superconducting phase characterized by small flux pinning forces.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Condensed Matter
Daigorou Hirai, Takahito Anbai, Takako Konoike, Shinya Uji, Yuya Hattori, Taichi Terashima, Hajime Ishikawa, Koichi Kindo, Naoyuki Katayama, Tamio Oguchi, Zenji Hiroi
Summary: Quantum oscillations were measured in the magnetic torque and electrical resistivity of ss-ReO2 to examine its electronic structure. The observed de Haas-van Alphen oscillation branches were consistent with first-principles calculations that predicted the presence of four Fermi surfaces. The small-electron Fermi surface exhibited a very small cyclotron mass, only 0.059 times that of free electrons, which suggests a linear dispersion of the energy band. These findings support the existence of the predicted hourglass nodal chain in ss-ReO2 near the Fermi energy.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Materials Science, Multidisciplinary
K. Nakagawa, M. Kimata, T. Yokouchi, Y. Shiomi
Summary: We report a large anisotropic magnetoresistance (AMR) in the surface states of antiferromagnetic semiconductor CrSb2. The angle-dependent magnetoresistance (ADMR) measurements were performed at low temperatures and high magnetic fields up to 24 T. At 1.4 K, where surface conduction is dominant, ADMR shows clear twofold symmetry consistent with AMR caused by magnetic-field-induced change in antiparallel magnetic structure. Despite the small angle dependence of net magnetic moments, the AMR magnitude reaches 9.3%, suggesting strong spin-orbit interaction in the surface conduction layer.
Article
Materials Science, Multidisciplinary
Taichi Terashima, Hishiro T. Hirose, Naoki Kikugawa, Shinya Uji, David Graf, Hitoshi Sugawara
Summary: This paper investigates a material composed of CeFe2Al10, which exhibits metallic conduction despite an increase in resistivity with decreasing temperature below 20K.
Article
Materials Science, Multidisciplinary
Yuya Hattori, Shunsuke Yoshizawa, Keisuke Sagisaka, Yuki Tokumoto, Keiichi Edagawa, Takako Konoike, Shinya Uji, Taichi Terashima
Summary: Scanning tunneling microscopy and transport measurements were used to investigate the electronic structure and temperature dependence in heavily Sr and Na codoped PbTe. The band gap increases with doping, leading to band convergence, which is desirable for thermoelectric materials. At higher temperatures, carrier redistribution occurs between different bands.
Article
Materials Science, Multidisciplinary
Hiroaki Hayashi, Yuichi Shirako, Lei Xing, Alexei A. Belik, Masao Arai, Masanori Kohno, Taichi Terashima, Hiroshi Kojitani, Masaki Akaogi, Kazunari Yamaura
Summary: In this study, the anomalous Hall effect in the cubic kagome antiferromagnet Mn3Sb is successfully measured, validating its theoretical predictions. These findings contribute to a comprehensive understanding of the anomalous Hall effect in noncollinear antiferromagnetic materials.
Article
Materials Science, Multidisciplinary
Taichi Terashima, Hishiro T. Hirose, Yoshitaka Matsushita, Shinya Uji, Hiroaki Ikeda, Yuki Fuseya, Teng Wang, Gang Mu
Summary: In this study, the electronic anisotropy of CaFeAsF was investigated by measuring its resistivity under magnetic fields with varying field directions. The results reveal the presence of electron anisotropy in iron-based compounds and provide insights into the nematic electronic state in various materials.
Article
Materials Science, Multidisciplinary
Takuma Ogasawara, Kim-Khuong Huynh, Stephane Yu Matsushita, Motoi Kimata, Time Tahara, Takanori Kida, Masayuki Hagiwara, Denis Arcon, Katsumi Tanigaki
Summary: We report a metal-insulator transition (MIT) in the half-filled multiorbital antiferromagnet BaMn2Bi2 that is tunable by a magnetic field. Scaling analyses reveal that the MIT is driven by Anderson localization instead of the expected Anderson-Mott mechanism. Electrical and thermoelectrical transport measurements, combined with electronic band calculations, show strong orbital-dependent correlation effects.
