Article
Materials Science, Multidisciplinary
Hongtao Rong, Zhenqiao Huang, Xin Zhang, Shiv Kumar, Fayuang Zhang, Chengcheng Zhang, Yuan Wang, Zhanyang Hao, Yongqing Cai, Le Wang, Cai Liu, Xiaoming Ma, Shu Guo, Bing Shen, Yi Liu, Shengtao Cui, Kenya Shimada, Quansheng Wu, Junhao Lin, Yugui Yao, Zhiwei Wang, Hu Xu, Chaoyu Chen
Summary: In this study, we investigate the band degeneracies in TaCo2Te2 crystals and demonstrate the realization of eightfold fermions and fourfold van Hove singularity through experimental and theoretical analyses. TaCo2Te2 serves as a topological quantum critical platform, which can be tuned into different phases by adding strain, magnetic field, or spin-orbit coupling. Our findings establish TaCo2Te2 as a platform to explore the interplay between symmetry and band topology.
NPJ QUANTUM MATERIALS
(2023)
Review
Multidisciplinary Sciences
B. Andrei Bernevig, Claudia Felser, Haim Beidenkopf
Summary: Magnetic topological materials have unique properties influenced by the topology of their electronic wave functions and magnetic spin configuration. In this review, we summarize the theoretical and experimental progress in this field and provide an outlook for future research.
Article
Materials Science, Multidisciplinary
Satyabrata Bera, Sudipta Chatterjee, Subhadip Pradhan, Suman Kalyan Pradhan, Sk Kalimuddin, Arnab Bera, Ashis K. Nandy, Mintu Mondal
Summary: In this study, we report a near room temperature 2D ferromagnet that shows a large anomalous Hall conductivity, which is attributed to the unique electronic structure and spin-orbit coupling effect. This material has the potential for important applications in spintronics.
Article
Materials Science, Multidisciplinary
Hongtao Rong, Liqin Zhou, Junbao He, Chunyao Song, Jianwei Huang, Cheng Hu, Yu Xu, Yongqing Cai, Hao Chen, Cong Li, Qingyan Wang, Lin Zhao, Zhihai Zhu, Guodong Liu, Zuyan Xu, Genfu Chen, Hongming Weng, X. J. Zhou
Summary: The study on the electronic structure of CaMnSb2 revealed the presence of a hole pocket around the Γ point and a tiny hole pocket at the Y point, with strong spectral weight accumulation and anisotropy observed. Furthermore, additional features along the Γ-Y line were observed that could not be explained by band structure calculations.
Review
Chemistry, Multidisciplinary
B. M. Anil Kumar, Satya N. Guin
Summary: Topological quantum materials have gained significant attention for their importance in both fundamental and technological aspects. From topological insulators to Dirac/Weyl semimetals, they exhibit exotic electronic structures like topological surface states and linear band dispersion. The unique electronic features, such as Weyl nodes and nodal lines, in these materials can lead to various enhanced properties, including thermoelectrics. This review focuses on the transverse thermoelectric effect, known as the Nernst effect, where an electrical signal is generated in the presence of a mutually perpendicular magnetic field and temperature gradient. The review provides an introduction to topological materials and the Nernst thermoelectric effect, discusses examples of materials in the latest developments, and explores the challenges and opportunities in this field.
MATERIALS CHEMISTRY FRONTIERS
(2023)
Article
Multidisciplinary Sciences
Amit Vashist, R. K. Gopal, Yogesh Singh
Summary: The study reveals unexpected Chiral anomaly-like features in the entire TI state range of Bi1-xSbx alloy, indicating the existence of a field induced WSM state in a broader x range, not just limited to the topological transition near x = 0.03.
SCIENTIFIC REPORTS
(2021)
Article
Astronomy & Astrophysics
Katsumasa Nakayama, Kei Suzuki
Summary: The Casimir effect is a quantum phenomenon caused by the zero-point energy of relativistic fields in a finite-size system. While this effect has been extensively studied in photon fields, its counterpart in fermion fields in Dirac/Weyl semimetals remains an open question. In this study, we theoretically demonstrate the characteristics of the Casimir effect in relativistic electron fields in Dirac/Weyl semimetals, using an effective Hamiltonian for realistic materials such as Cd3As2 and Na3Bi. We observe an oscillation of the Casimir energy with the thickness of the thin film, which is attributed to the existence of Dirac/Weyl nodes in momentum space. This effect can be experimentally observed in thin films of semimetals, where the thickness-dependent thermodynamic quantities are influenced by the Casimir energy.
Article
Physics, Multidisciplinary
Anastasios Markou, Jacob Gayles, Elena Derunova, Peter Swekis, Jonathan Noky, Liguo Zhang, Mazhar N. Ali, Yan Sun, Claudia Felser
Summary: The article discusses the characteristics and transport properties of topological magnetic semimetals, highlighting the highly symmetric structures and significant anomalous Hall effects of certain compounds. Additionally, it demonstrates the combination of experimental and theoretical approaches in studying these materials.
COMMUNICATIONS PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Kwan-Young Lee, Jae-Hyun Yun, Jin Hee Kim, Yusuff Adeyemi Salawu, Heon-Jung Kim, Jae Jun Lee, Hosun Lee, Jong-Soo Rhyee
Summary: This study suggests the coexistence of Weyl semimetal and Kondo effect in disordered Mn-doped MnxVAl3. The experiment confirms the presence of Kondo effect through resistivity measurements and other characteristics. The combination of dilute Mn-doping and chemical potential adjustment leads to the transition from Dirac to Weyl semimetal. The research also demonstrates the topological phase transition induced by the temperature.
MATERIALS TODAY PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Mizuki Ohno, Masaki Uchida, Ryosuke Kurihara, Susumu Minami, Yusuke Nakazawa, Shin Sato, Markus Kriener, Motoaki Hirayama, Atsushi Miyake, Yasujiro Taguchi, Ryotaro Arita, Masashi Tokunaga, Masashi Kawasaki
Summary: We report the fabrication of EuSb2 single-crystalline films and investigation of their quantum transport. The first-principles calculations reveal that EuSb2 is a magnetic topological nodal-line semimetal protected by nonsymmorphic symmetry. The observed Shubnikov-de Haas oscillations with multiple frequency components suggest the presence of small effective masses and two-dimensional field-angle dependence, indicating possible contributions of surface states even in a 250 nm thick film. This finding of a high-mobility magnetic topological semimetal will stimulate further research in exotic quantum transport phenomena by manipulating magnetic order in topological semimetal films.
Article
Multidisciplinary Sciences
Ying-Ming Xie, Xue-Jian Gao, Xiao Yan Xu, Cheng-Ping Zhang, Jin-Xin Hu, Jason Z. Gao, K. T. Law
Summary: Recent research suggests that all chiral crystals with spin-orbit coupling can be Kramers Weyl semimetals, while all achiral non-centrosymmetric materials with spin-orbit coupling may be a new class of topological materials known as Kramers nodal line metals. These materials exhibit doubly degenerate lines connecting time-reversal invariant momenta, resulting in two types of Fermi surfaces.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Tommy Tai, Ching Hua Lee
Summary: This paper investigates the semiclassical optical response of two nodal loops in linked, unlinked, and touching configurations. A geometric picture is provided to unify the aspects of nodal topology and geometry, shedding light on the effects of nodal topology and geometry on material properties.
Article
Materials Science, Multidisciplinary
Sudip Malick, A. B. Sarkar, Antu Laha, M. Anas, V. K. Malik, Amit Agarwal, Z. Hossain, J. Nayak
Summary: This study investigates the electronic and topological properties of single-crystal SrAl2Si2 through magnetotransport experiments and first-principle calculations. The research reveals several remarkable features at low temperatures, such as large nonsaturating magnetoresistance, Shubnikov-de Haas oscillations, and cusplike magnetoconductivity.
Article
Chemistry, Physical
Wenbin Wu, Zeping Shi, Yuhan Du, Yuxiang Wang, Fang Qin, Xianghao Meng, Binglin Liu, Yuanji Ma, Zhongbo Yan, Mykhaylo Ozerov, Cheng Zhang, Hai-Zhou Lu, Junhao Chu, Xiang Yuan
Summary: The manuscript reports experimental observations of a Lifshitz transition in a topological insulator HfTe5 under a strong magnetic field, leading to the formation of one-dimensional Weyl modes in a three-dimensional material. By tracking the Landau level transitions, the study demonstrates that band inversion drives the crossing of zeroth Landau bands and the formation of a one-dimensional Weyl mode. This transition occurs at 21 T and moves the Weyl mode close to the Fermi level.
Review
Physics, Multidisciplinary
B. Q. Lv, T. Qian, H. Ding
Summary: Topological semimetals are characterized by bulk band crossings, which have led to increased research activities in the field due to precise theoretical predictions, well-controlled material synthesis, and advanced characterization techniques. The distinct features of these materials include dimensionality, degeneracy, slope and order of band dispersion, topological invariants, and crystallographic symmetries that stabilize band crossings. Additionally, the unique properties of various topological semimetal phases, such as nontrivial surface states and transport responses, have been reviewed.
REVIEWS OF MODERN PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Ying Qin, Mohammed Sayyad, Alejandro R-P Montblanch, Matthew S. G. Feuer, Dibyendu Dey, Mark Blei, Renee Sailus, Dhiren M. Kara, Yuxia Shen, Shize Yang, Antia S. Botana, Mete Atature, Sefaattin Tongay
Summary: A new synthesis technique for 2D Janus monolayers with real-time monitoring capability has been introduced, yielding high optical quality results. The versatility of this method was demonstrated by synthesizing and monitoring the conversion of different Janus monolayers, showcasing its practicality and functionality.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Grace A. Pan, Dan Ferenc Segedin, Harrison LaBollita, Qi Song, Emilian M. Nica, Berit H. Goodge, Andrew T. Pierce, Spencer Doyle, Steve Novakov, Denisse Cordova Carrizales, Alpha T. N'Diaye, Padraic Shafer, Hanjong Paik, John T. Heron, Jarad A. Mason, Amir Yacoby, Lena F. Kourkoutis, Onur Erten, Charles M. Brooks, Antia S. Botana, Julia A. Mundy
Summary: This study reports the synthesis of Nd6Ni5O12, a new type of superconducting nickelate material that achieves optimal cuprate-like electron filling without the need for chemical doping. The material exhibits a superconducting transition around 13K and displays behavior intermediate between cuprate-like and infinite-layer nickelate-like behavior. This indicates that square-planar nickelates are a new family of superconductors that can be tuned through both doping and dimensionality.
Review
Physics, Multidisciplinary
Antia S. Botana, Kwan-Woo Lee, Michael R. Norman, Victor Pardo, Warren E. Pickett
Summary: The discovery of superconductivity in thin films of infinite-layer hole-doped NdNiO2 has reignited research on high-temperature superconductivity. The debate over the relationship between nickelates and cuprates, and the focus on the differences between nickel and copper, continues. Recent studies have explored the electronic structures of layered NiO2 materials to compare them with cuprates and identify future research directions.
FRONTIERS IN PHYSICS
(2022)
Review
Chemistry, Multidisciplinary
Clarice D. Aiello, John M. Abendroth, Muneer Abbas, Andrei Afanasev, Shivang Agarwal, Amartya S. Banerjee, David N. Beratan, Jason N. Belling, Bertrand Berche, Antia Botana, Justin R. Caram, Giuseppe Luca Celardo, Gianaurelio Cuniberti, Aitzol Garcia-Etxarri, Arezoo Dianat, Ismael Diez-Perez, Yuqi Guo, Rafael Gutierrez, Carmen Herrmann, Joshua Hihath, Suneet Kale, Philip Kurian, Ying-Cheng Lai, Tianhan Liu, Alexander Lopez, Ernesto Medina, Vladimiro Mujica, Ron Naaman, Mohammadreza Noormandipour, Julio L. Palma, Yossi Paltiel, William Petuskey, Joao Carlos Ribeiro-Silva, Juan Jose Saenz, Elton J. G. Santos, Maria Solyanik-Gorgone, Volker J. Sorger, Dominik M. Stemer, Jesus M. Ugalde, Ana Valdes-Curiel, Solmar Varela, David H. Waldeck, Michael R. Wasielewski, Paul S. Weiss, Helmut Zacharias, Qing Hua Wang
Summary: This review focuses on the study of chiral degrees of freedom in matter and electromagnetic fields, discussing the recent observations of the chiral-induced spin selectivity effect and the nanophotonic strategies designed to amplify chiral light-matter interactions. The CISS effect offers opportunities for spin control and the design of room-temperature quantum devices, while chiral-optical effects could have advantages in all-optical and quantum information technologies. The review presents a vision for the future roles of chiral-influenced quantum effects in enabling room-temperature quantum technologies.
Article
Multidisciplinary Sciences
Qian Song, Connor A. Occhialini, Emre Ergecen, Batyr Ilyas, Danila Amoroso, Paolo Barone, Jesse Kapeghian, Kenji Watanabe, Takashi Taniguchi, Antia S. Botana, Silvia Picozzi, Nuh Gedik, Riccardo Comin
Summary: This article reports the discovery of type-II multiferroic order in a single atomic layer of the transition-metal-based van der Waals material NiI2. The multiferroic state of NiI2 is characterized by a proper-screw spin helix that induces chirality-controlled electrical polarization. Through various optical measurements and theoretical simulations, it is found that NiI2 has a highly anisotropic electronic state that breaks both rotational and inversion symmetry, supporting polar order. Interestingly, the ordered magnetic polar state persists down to the monolayer level of NiI2. These findings introduce a new platform for studying emergent multiferroic phenomena, chiral magnetic textures, and ferroelectricity in the realm of two-dimensional van der Waals materials.
Article
Physics, Multidisciplinary
Y. Shen, J. Sears, G. Fabbris, J. Li, J. Pelliciari, I Jarrige, Xi He, I Bozovic, M. Mitrano, Junjie Zhang, J. F. Mitchell, A. S. Botana, V Bisogni, M. R. Norman, S. Johnston, M. P. M. Dean
Summary: The essential electronic properties of low valence nickelates have been debated, whether they have appreciable oxygen charge-transfer character or are in a distinct Mott-Hubbard regime. Using O K-edge resonant inelastic x-ray scattering (RIXS), this study resolved the question and found that the low valence nickelate possesses mixed charge-transfer-Mott-Hubbard character. Despite a similar Coulomb repulsion, the transition-metal-oxygen hopping is larger in the nickelate, leading to a significant superexchange interaction and hole occupation of ligand O orbitals.
Article
Chemistry, Inorganic & Nuclear
Zachary T. Messegee, Jun Sang Cho, Andrew J. Craig, V. Ovidiu Garlea, Yan Xin, Chang-Jong Kang, Thomas E. Proffen, Hari Bhandari, Jordan C. Kelly, Nirmal J. Ghimire, Jennifer A. . Aitken, Joon I. Jang, Xiaoyan Tan
Summary: In this study, Cu2TSiS4 (T = Mn and Fe) polycrystalline and single-crystal materials were prepared using high-temperature solid-state and chemical vapor transport methods. The polar crystal structure was confirmed by various techniques, including neutron powder diffraction, X-ray single-crystal refinement, electron diffraction, energy-dispersive X-ray spectroscopy, and second harmonic generation (SHG). Magnetic measurements showed antiferromagnetic ordering at 8 K and 14 K for the two compounds, supported by temperature-dependent neutron powder diffraction data. Additional magnetic reflections were observed at 2 K and can be described by specific magnetic propagation vectors for each compound. The refined antiferromagnetic structure revealed the tilting of Mn/Fe spins away from the ac plane and the calculated total magnetic moments. Both compounds exhibited modest second-order nonlinear susceptibilities.
INORGANIC CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
S. X. M. Riberolles, Tyler J. Slade, R. L. Dally, P. M. Sarte, Bing Li, Tianxiong Han, H. Lane, C. Stock, H. Bhandari, N. J. Ghimire, D. L. Abernathy, P. C. Canfield, J. W. Lynn, B. G. Ueland, R. J. McQueeney
Summary: It is predicted that ferromagnetic order in a two-dimensional kagome layer can generate a topological Chern insulator without an applied magnetic field. In TbMn6Sn6, the uniaxial magnetic anisotropy of Tb3+ ions can effectively generate the Chern state within the FM Mn kagome layers, while a spin-reorientation transition provides a mechanism for switching. Inelastic neutron scattering is used to gain insights into the fundamental nature of the spin-reorientation transition.
NATURE COMMUNICATIONS
(2023)
Editorial Material
Multidisciplinary Sciences
Qian Song, Connor A. Occhialini, Emre Ergecen, Batyr Ilyas, Danila Amoroso, Paolo Barone, Jesse Kapeghian, Kenji Watanabe, Takashi Taniguchi, Antia S. Botana, Silvia Picozzi, Nuh Gedik, Riccardo Comin
Article
Materials Science, Multidisciplinary
M. R. Norman, A. S. Botana, J. Karp, A. Hampel, H. LaBollita, A. J. Millis, G. Fabbris, Y. Shen, M. P. M. Dean
Summary: This paper presents a simple formalism for calculating x-ray absorption and resonant inelastic x-ray scattering, which uses the density of states as input from a single-particle or many-body ab initio calculation and is designed to capture itinerant like features. The formalism is applied to calculate XAS and RIXS for reduced valence nickelates, cuprate, and unreduced nickelate compounds. The results show strong orbital polarization in reduced valence nickelates and reproduce key aspects of a recent RIXS experiment for R4Ni3O8. Implications for the nature of 3d electrons in reduced valence nickelates are discussed.
Article
Chemistry, Inorganic & Nuclear
Callista M. Skaggs, Dong-Choon Ryu, Hari Bhandari, Yan Xin, Chang-Jong Kang, Saul H. Lapidus, Peter E. Siegfried, Nirmal J. Ghimire, Xiaoyan Tan
Summary: Polycrystalline IrGe4 with a chiral crystal structure is synthesized and exhibits metallic behavior and non-saturating magnetoresistance under an applied magnetic field.
INORGANIC CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Harrison LaBollita, Myung-Chul Jung, Antia S. Botana
Summary: This study investigates the many-body electronic structure of layered nickelates and reveals that their electronic features are highly tunable as the dimensionality changes. The findings provide valuable insights into the potential of these materials as unconventional superconductors.
Article
Materials Science, Multidisciplinary
Xian P. Yang, Harrison LaBollita, Zi-Jia Cheng, Hari Bhandari, Tyler A. Cochran, Jia-Xin Yin, Md Shafayat Hossain, Ilya Belopolski, Qi Zhang, Yuxiao Jiang, Nana Shumiya, Daniel Multer, Maksim Liskevich, Dmitry A. Usanov, Yanliu Dang, Vladimir N. Strocov, Albert Davydov, Nirmal J. Ghimire, Antia S. Botana, M. Zahid Hasan
Summary: Co1/3NbS2, a layered transition metal dichalcogenide, exhibits different orbital characteristics and band dispersion after Co intercalation, indicating the introduction of out-of-plane electronic correlations. This study provides a new perspective on the compound and proposes the potential to generate exotic phases by tuning the Fermi level.
Article
Materials Science, Multidisciplinary
Myung-Chul Jung, Jesse Kapeghian, Chase Hanson, Betul Pamuk, Antia S. Botana
Summary: We analyze the electronic structure of the higher-order nickelate Ruddlesden-Popper phases and find similarities and differences with optimally hole-doped cuprates. The results show large holelike Fermi surfaces and the appearance of non-cuprate-like bands for higher values of n. This series of nickelates can potentially shed light on the physics of copper-based oxides.
Article
Materials Science, Multidisciplinary
Harrison LaBollita, Antia S. Botana
Summary: In this study, we compared two superconducting members of the rare-earth layered nickelate family and found that hole-doped RNiO2 and quintuple-layer R6Ni5O12 exhibit nearly identical electronic structures and many-body correlation effects at the same nominal carrier concentration. However, the fermiology of the quintuple-layer nickelate is more two-dimensional-like, making it more cupratelike without the need for chemical doping.
