Article
Materials Science, Multidisciplinary
Zi-Shan Liao, Hong-Hao Zhang, Zhongbo Yan
Summary: In time-reversal invariant systems, while the anomalous Hall effect vanishes in the linear response regime, a nonlinear Hall effect can emerge if the inversion symmetry is broken. Our study in two-dimensional doped insulators and semimetals of symmetry class AI shows that despite lacking strong topological insulator phases, they can still exhibit interesting topological properties. The behavior of Berry curvature dipoles in relation to doping levels and phase transitions reveals potential for application of the nonlinear Hall effect in these materials.
Article
Materials Science, Multidisciplinary
D. Shcherbakov, Jiawei Yang, Shahriar Memaran, Kenji Watanabe, Takashi Taniguchi, Dmitry Smirnov, Luis Balicas, Chun Ning Lau
Summary: We perform magnetotransport studies on atomically thin InSe field-effect transistors with large Rashba spin-orbit coupling. We extract the Landau level gaps through thermal activation measurements and find that the gaps at even and odd filling factors have positive and negative intercepts at B = 0, respectively, due to spin-split Landau spectrum. We also demonstrate that for materials with strong spin-orbit coupling, the Landau level gaps may vary nonlinearly and nonmonotonically with magnetic field, making the extraction of effective mass and g-factor sensitive to the strength and tunability of SOC.
Article
Chemistry, Multidisciplinary
Lixuan Tai, Bingqian Dai, Jie Li, Hanshen Huang, Su Kong Chong, Kin L. Wong, Huairuo Zhang, Peng Zhang, Peng Deng, Christopher Eckberg, Gang Qiu, Haoran He, Di Wu, Shijie Xu, Albert Davydov, Ruqian Wu, Kang L. Wang
Summary: In this study, the researchers confirm the genuine topological Hall effect (THE) with the anomalous Hall effect (AHE) through transport and magneto-optical Kerr effect microscopy. The presence of magnetic skyrmions is directly observed, and genuine THE is found to occur in the transition region of the AHE. The researchers also distinguish between artifact THE and genuine THE using minor loops, temperature dependence, and gate dependence.
Article
Crystallography
Chenxiao Ye, Jiantao Che, Hai Huang
Summary: Based on the two-band Bogoliubov-de Gennes theory, we investigated the boundary effect of the interface between the two-gap superconductor FeSe and insulator (or vacuum). We introduced new boundary terms into the two-band Ginzburg-Landau formalism, which modified the boundary conditions for the corresponding order parameters of the superconductor. Our theory allowed for a mean-field calculation of the suppression of the critical temperature as the FeSe film thickness decreases. Our numerical results were in good agreement with the experimental data observed in this material.
Article
Physics, Condensed Matter
Tsadik Kidanemariam, Gebregziabher Kahsay
Summary: In this research work, the theoretical study of the superconducting properties in the iron-based superconductor Ba1-xKxFe2As2 is investigated. The mathematical expressions and phase diagrams for the superconducting order parameters, transition temperature, density of states, and condensation energy are derived. The obtained results show enhanced superconducting order parameter and transition temperature, which are consistent with previous experimental findings.
EUROPEAN PHYSICAL JOURNAL B
(2023)
Article
Chemistry, Multidisciplinary
Yangyang Feng, Ying Dai, Baibiao Huang, Liangzhi Kou, Yandong Ma
Summary: This article proposes a new mechanism of Layer Hall effect (LHE) by coupling layer physics with multiferroics using symmetry analysis and a low-energy k·p model. The LHE is generated by the combination of time-reversal symmetry breaking and valley physics, resulting in layer-polarized Berry curvature that forces electrons to deflect in one direction of a given layer. The controllable and reversible LHE is verified in the multiferroic material of bilayer Co2CF2 through first-principles calculations. This finding opens a new direction for LHE and 2D materials research.
Article
Chemistry, Physical
Yi-Na Huang, Xiang-Long Yu, Da-Yong Liu, Miao-Miao Han
Summary: The study shows that CaAFe(4)As(4) can achieve a superconducting transition temperature of 31-36 K without doping. The introduced alkali metals can induce hole doping and chemical pressure effects, which can affect the superconducting transition temperature by changing the number of electrons and the structure of the FeAs conductive layer.
Article
Optics
Qi Song, Haixia Da
Summary: This study investigated the photonic spin Hall effect of a superconductor slab using transfer matrix method and angular spectrum theory. It was found that the maximum positive spin shift can be achieved in a superconductor slab with the appropriate thickness, and the magnitudes and positions of the peak and valley in the spectrum of spin shift are sensitive to the temperature of the superconductor. These findings provide the possibility for realizing the controllable photonic spin Hall effect with superconductors, suggesting potential applications in spin photonic devices.
OPTICS COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Alberto Hijano, Sakineh Vosoughi-nia, F. Sebastian Bergeret, Pauli Virtanen, Tero T. Heikkila
Summary: We extended the Mattis-Bardeen theory to include various types of Hall responses in superconductors. By modifying the quasiclassical Usadel equation, we were able to analyze Hall effects in disordered superconductors and consider the precise frequency dependence of these effects. Our results provide a foundation for analyzing dynamic experiments, particularly in novel thin-film superconductors where ordinary Hall and spin Hall effects can occur simultaneously.
Article
Optics
Lei Kang, Yuhao Wu, Douglas H. Werner
Summary: The insulator-to-metal transition in vanadium dioxide induces large material property variations, making it suitable for reconfigurable metadevices across a broad frequency band. By incorporating VO2 into metallic resonating structures, strong electromagnetic resonances in the THz regime can be achieved, offering potential for active manipulation of THz radiation. Utilizing VO2 dipole antennas, geometric phase coded metasurfaces for wave-front shaping and polarization rotation of THz waves can be realized, with the efficiency of the THz spin Hall effect closely related to VO2's THz electrical conductivity.
Article
Physics, Multidisciplinary
Vladislav D. Kurilovich, Leonid I. Glazman
Summary: This article develops a theory of the nonlocal transport of two counterpropagating nu = 1 quantum Hall edges coupled via a narrow disordered superconductor. Contrary to predictions, the edge states proximitized in this way do not turn into a topological superconductor, but are tuned to the critical point between trivial and topological phases.
Article
Chemistry, Physical
Kosuke Tanabe, Shintaro Hatoyama, Hirofumi Wada, Alexander V. Andreev, Kunihiko Yamauchi, Tamio Oguchi, Hisatomo Harima
Summary: The Hall effect of RCo2 with R = Er and Lu was investigated. LuCo2 exhibits exchange-enhanced Pauli paramagnetism, while ErCo2 undergoes a first-order magnetic transition at TC = 32 K. The Hall resistivity pxy was measured as a function of magnetic field B at different temperatures. The normal Hall coefficient RN and the anomalous Hall coefficient RA were estimated from the analysis of the pxy-B curves and magnetization curves. The temperature dependence of RN in LuCo2 and the sign change in RA of ErCo2 were discussed.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Engineering, Electrical & Electronic
Bijun Tang, Xiaowei Wang, Mengjiao Han, Xiaodong Xu, Zhaowei Zhang, Chao Zhu, Xun Cao, Yumeng Yang, Qundong Fu, Jianqun Yang, Xingji Li, Weibo Gao, Jiadong Zhou, Junhao Lin, Zheng Liu
Summary: Cr5Te8 flakes with strong ferromagnetism and unique magnetotransport properties can be grown using chemical vapour deposition.
NATURE ELECTRONICS
(2022)
Article
Chemistry, Multidisciplinary
Mo Cheng, Xiaoxu Zhao, Yan Zeng, Peng Wang, Yuzhu Wang, Ti Wang, Stephen John Pennycook, Jun He, Jianping Shi
Summary: A temperature-mediated CVD method was developed to grow ultrathin nonlayered FeTe nanosheets on mica substrates, with a high-efficiency transfer method also designed. The 2D hexagonal FeTe exhibited exciting ferromagnetism and high conductivity. These findings could promote the further development of phase-tunable synthesis and green transfer techniques for 2D Fe-chalcogenides.
Article
Materials Science, Ceramics
Lakshmana Kumar Bommineedi, T. Kedara Shivasharma, Babasaheb R. Sankapal
Summary: Iron telluride based thin films with nanopebbles have been successfully grown on stainless steel substrates using the SILAR process, showing mixed phase growth and enhanced hydrophilic nature. The films exhibit high specific capacitance and pseudo capacitive contribution, demonstrating excellent electrochemical performance.
CERAMICS INTERNATIONAL
(2022)
Article
Physics, Applied
D. Torsello, R. Gerbaldo, L. Gozzelino, F. Laviano, A. Takahashi, A. Park, S. Pyon, A. Ichinose, T. Tamegai, G. Ghigo
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2020)
Article
Nanoscience & Nanotechnology
Ataru Ichinose, Tsuyoshi Hamada, Keisuke Ota, Iwao Kawayama, Toshiya Doi
Article
Materials Science, Multidisciplinary
Sunseng Pyon, Yuto Kobayashi, Ayumu Takahashi, Wenjie Li, Teng Wang, Gang Mu, Ataru Ichinose, Tadashi Kambara, Atsushi Yoshida, Tsuyoshi Tamegai
PHYSICAL REVIEW MATERIALS
(2020)
Article
Physics, Applied
Ataru Ichinose, Sunseng Pyon, Tsuyoshi Tamegai, Shigeyuki Ishida
Summary: CaKFe4As4 single crystals exhibit significant anisotropy in critical current density (J(C)), with planar defects originating from KFe2As2 step networks, and dark contrast regions observed in STEM result from local strain distributions caused by the substitution of Ca by K.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Akihiro Kikuchi, Yasuo Iijima, Shigeki Nimori, Masaru Yamamoto, Masahiko Kawano, Motoyoshi Kimura, Jun Nagamatsu, Masato Otsubo, Ataru Ichinose, Kiyosumi Tsuchiya
Summary: The study shows that the critical current density of Nb3Al wires increases with decreasing diameter, with the maximum Jc obtained on 30 m diameter wires. A 7-wire round cable and a 3rd bundle Rutherford cable have been successfully fabricated using these wires. Transport current tests showed no differences in Ic and n-values between different processes.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Physics, Applied
Kiyosumi Tsuchiya, Xudong Wang, Shinji Fujita, Ataru Ichinose, Kyohei Yamada, Akio Terashima, Akihiro Kikuchi
Summary: The research investigates the development and commercialization of rare-earth barium copper oxide coated conductors, as well as the current-carrying capabilities of conductors doped with artificial pinning centers in high magnetic fields. The testing results show that conductors with artificial pinning centers have significantly higher critical current values under perpendicular fields and perform well under high magnetic fields.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Tomoya Horide, Ataru Ichinose, Fumiaki Tokura, Kaname Matsumoto
Summary: Nanocomposite films containing self-organized oxide nanocolumns were fabricated by pulsed laser deposition, showing the formation of Sr-Ti-O nanocolumns with a diameter of 2-5 nm and spacing <10 nm at specific deposition temperature and STO content. The morphology of nanocolumns in chalcogenide-oxide nanocomposites is expected to effectively influence the properties of chalcogenides.
Article
Chemistry, Physical
Sunseng Pyon, Soichi Taya, Yuto Kobayashi, Ayumu Takahashi, Wenjie Li, Toshihiro Taen, Teng Wang, Gang Mu, Hisashi Kitamura, Ataru Ichinose, Tsuyoshi Tamegai
Summary: The study investigates the critical current density and vortex pinning properties in single crystals of a novel iron-based superconductor KCa2Fe4As4F2, showing significant enhancement of performance after irradiation. Vortex dynamics in KCa2Fe4As4F2 are found to be similar to (Ba,K)Fe2As2 to some extent, but different from Li0.8Fe0.2OHFeSe.
Article
Chemistry, Physical
Giovanna Latronico, Saurabh Singh, Paolo Mele, Abdalla Darwish, Sergey Sarkisov, Sian Wei Pan, Yukihiro Kawamura, Chihiro Sekine, Takahiro Baba, Takao Mori, Tsunehiro Takeuchi, Ataru Ichinose, Simeon Wilson
Summary: The addition of 2% SnO2 significantly enhances the thermoelectric performance of AZO thin films on silica substrates, particularly in terms of power factor. Compared to typical AZO materials, the thermal conductivity is significantly reduced.
Article
Engineering, Electrical & Electronic
Shintaro Adachi, Ataru Ichinose, Fumiko Kimura, Shigeru Horii
Summary: This study examined the twinned microstructures of a magnetically biaxial aligned grain of DyBa2Cu3Oy using transmission electron microscopy (TEM). Planar views of the grain were obtained more easily through the use of biaxial aligned grain. The study revealed an inhomogeneous abundance ratio of two different types of domains, which suggested the presence of triaxial magnetic anisotropy at the grain level and its contribution to the biaxial alignment of RE123 grains under MRFs.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2022)
Article
Physics, Applied
Tomoya Horide, Hiromu Katagiri, Ataru Ichinose, Kaname Matsumoto
Summary: The incorporation of different materials can control the phase formation and nanostructure of Fe(Te,Se) films, thus affecting their superconducting properties. Adding SrTiO3 to the films resulted in c-axis oriented structures and the formation of nanocomposite structures with increasing SrTiO3 content.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Mitsuhiro Muta, Suguru Nishikawa, Ataru Ichinose, Yukio Sato, Makoto Arita, Yoshifumi Ikoma, Masashi Mukaida
Summary: Preferred orientation and optical responses were investigated for BaBiO3 films grown by pulsed laser deposition. The films exhibited monoclinic symmetry I2/m and a (110) preferred orientation. The estimated optical bandgaps were around 2.3 eV for direct transition and 2.1 eV for indirect transition. The decay time of photoconductivity was found to be approximately 0.48 sec. The relationship between ultraviolet light-induced photoconductivity and film crystallinity was clarified, with high-quality crystalline BaBiO3 films exhibiting lower photoconductivity, contrary to TiO2 films.
Article
Physics, Applied
Tomoya Horide, Ataru Ichinose, Masashi Tanaka, Kaname Matsumoto
Summary: The control of nanostructure is crucial in both fundamental and technological aspects, as it determines various properties of superconductors such as vortex pinning. Although the nanostructure control in superconducting oxides is well-established, it remains challenging in iron-based superconductors due to the possibility of anionic substitution and non-stoichiometric anion. In this study, compositional inhomogeneity originating from phase separation was observed in Fe(Te,Se) films prepared through pulsed laser deposition. The compositional inhomogeneity was absent in films deposited at lower temperature, while high-temperature deposited films showed an anion distribution with the size of about 8 nm due to phase separation. The obtained structure is expected to function as an effective pinning center in high magnetic fields after further optimization, demonstrating a novel method of nanostructure control in Fe(Te,Se) different from nanocomposite formation in oxides.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Wenjie Li, Sunseng Pyon, Akiyoshi Yagi, Cheng Yu, Ryosuke Sakagami, Ataru Ichinose, Satoru Okayasu, Tsuyoshi Tamegai
Summary: Various peak effects induced by particle irradiations were investigated in 2H-NbSe2 single crystals. The peak effect induced by order-disorder transition of vortices was magnified by 3 MeV proton irradiation, while the peak effect in NbSe2 with splayed columnar defects showed a shift towards low fields with increasing splayed angle. Numerical calculations confirmed the mechanism behind the peak effect, and field dependence analysis revealed the formation of non-uniform J(c) flow. Coexistence of different peak effects was observed in symmetric splayed CD samples generated by Xe and Au ions, and a broad anomalous peak effect similar to iron-based superconductors was observed in Au-irradiated samples with small splay angle, which was suppressed by an externally applied magnetic field parallel to one of the splayed CDs.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
F. Nabeshima, Y. Kawai, N. Shikama, Y. Sakishita, A. Suter, T. Prokscha, S. E. Park, S. Komiya, A. Ichinose, T. Adachi, A. Maeda
Summary: Muon spin rotation/relaxation measurements were used to investigate the magnetic properties of FeSe1-xSx thin films on LaAlO3. The results show that S substitution induces magnetism at low temperatures in the films, with the anomaly temperature increasing and magnetic fluctuations being suppressed with increasing S content. The behavior of Tc is significantly different between the FeSe films under chemical pressure from S substitution compared to bulk FeSe under hydrostatic pressure.
