1
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Balduini F, Molinari A, Rocchino L, Hasse V, Felser C, Sousa M, Zota C, Schmid H, Grushin AG, Gotsmann B. Intrinsic negative magnetoresistance from the chiral anomaly of multifold fermions. Nat Commun 2024; 15:6526. [PMID: 39095356 PMCID: PMC11297145 DOI: 10.1038/s41467-024-50451-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 07/10/2024] [Indexed: 08/04/2024] Open
Abstract
The chiral anomaly - a hallmark of chiral spin-1/2 Weyl fermions - is an imbalance between left- and right-moving particles that underpins phenomena such as particle decay and negative longitudinal magnetoresistance in Weyl semimetals. The discovery that chiral crystals can host higher-spin generalizations of Weyl quasiparticles without high-energy counterparts, known as multifold fermions, raises the fundamental question of whether the chiral anomaly is a more general phenomenon. Answering this question requires materials with chiral quasiparticles within a sizable energy window around the Fermi level that are unaffected by extrinsic effects such as current jetting. Here, we report the chiral anomaly of multifold fermions in CoSi, which features multifold bands within ~0.85 eV of the Fermi level. By excluding current jetting through the squeezing test, we measure an intrinsic, longitudinal negative magnetoresistance. We develop a semiclassical theory to show that the negative magnetoresistance originates in the chiral anomaly, despite a sizable and detrimental orbital magnetic moment contribution. A concomitant non-linear Hall effect supports the multifold-fermion origin of the magnetotransport. Our work confirms the chiral anomaly of higher-spin generalizations of Weyl fermions, currently inaccessible outside solid-state platforms.
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Affiliation(s)
- Federico Balduini
- IBM Research Europe - Zurich, Säumerstrasse, Ruschlikon, Switzerland.
| | - Alan Molinari
- IBM Research Europe - Zurich, Säumerstrasse, Ruschlikon, Switzerland
| | - Lorenzo Rocchino
- IBM Research Europe - Zurich, Säumerstrasse, Ruschlikon, Switzerland
| | - Vicky Hasse
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, Dresden, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, Dresden, Germany
| | - Marilyne Sousa
- IBM Research Europe - Zurich, Säumerstrasse, Ruschlikon, Switzerland
| | - Cezar Zota
- IBM Research Europe - Zurich, Säumerstrasse, Ruschlikon, Switzerland
| | - Heinz Schmid
- IBM Research Europe - Zurich, Säumerstrasse, Ruschlikon, Switzerland
| | - Adolfo G Grushin
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 25 Av. des Martyrs, Grenoble, France.
| | - Bernd Gotsmann
- IBM Research Europe - Zurich, Säumerstrasse, Ruschlikon, Switzerland.
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2
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Johansson A. Theory of spin and orbital Edelstein effects. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:423002. [PMID: 38955339 DOI: 10.1088/1361-648x/ad5e2b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Accepted: 07/01/2024] [Indexed: 07/04/2024]
Abstract
In systems with broken spatial inversion symmetry, such as surfaces, interfaces, or bulk systems lacking an inversion center, the application of a charge current can generate finite spin and orbital densities associated with a nonequilibrium magnetization, which is known as spin and orbital Edelstein effect (SEE and OEE), respectively. Early reports on this current-induced magnetization focus on two-dimensional Rashba systems, in which an in-plane nonequilibrium spin density is generated perpendicular to the applied charge current. However, until today, a large variety of materials have been theoretically predicted and experimentally demonstrated to exhibit a sizeable Edelstein effect, which comprises contributions from the spin as well as the orbital degrees of freedom, and whose associated magnetization may be out of plane, nonorthogonal, and even parallel to the applied charge current, depending on the system's particular symmetries. In this review, we give an overview on the most commonly used theoretical approaches for the discussion and prediction of the SEE and OEE. Further, we introduce a selection of the most intensely discussed materials exhibiting a finite Edelstein effect, and give a brief summary of common experimental techniques.
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Affiliation(s)
- Annika Johansson
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle (Saale), Germany
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3
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Zhang Y, Ma Y, Sun W, Li W, Li G. Structural and Electronic Chirality in Inorganic Crystals: from Construction to Application. Chemistry 2024; 30:e202400436. [PMID: 38571318 DOI: 10.1002/chem.202400436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/31/2024] [Accepted: 04/03/2024] [Indexed: 04/05/2024]
Abstract
Chirality represents a fundamental characteristic inherent in nature, playing a pivotal role in the emergence of homochirality and the origin of life. While the principles of chirality in organic chemistry are well-documented, the exploration of chirality within inorganic crystal structures continues to evolve. This ongoing development is primarily due to the diverse nature of crystal/amorphous structures in inorganic materials, along with the intricate symmetrical and asymmetrical relationships in the geometry of their constituent atoms. In this review, we commence with a summary of the foundational concept of chirality in molecules and solid states matters. This is followed by an introduction of structural chirality and electronic chirality in three-dimensional and two-dimensional inorganic materials. The construction of chirality in inorganic materials is classified into physical photolithography, wet-chemistry method, self-assembly, and chiral imprinting. Highlighting the significance of this field, we also summarize the research progress of chiral inorganic materials for applications in optical activity, enantiomeric recognition and chiral sensing, selective adsorption and enantioselective separation, asymmetric synthesis and catalysis, and chirality-induced spin polarization. This review aims to provide a reference for ongoing research in chiral inorganic materials and potentially stimulate innovative strategies and novel applications in the realm of chirality.
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Affiliation(s)
- Yudi Zhang
- CAS Key Laboratory of Magnetic Materials and Devices, and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- University of Chinese Academy of Sciences, 19 A Yuquan Rd, Shijingshan District, Beijing, 100049, China
| | - Yuzhe Ma
- CAS Key Laboratory of Magnetic Materials and Devices, and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- University of Chinese Academy of Sciences, 19 A Yuquan Rd, Shijingshan District, Beijing, 100049, China
| | - Wen Sun
- CAS Key Laboratory of Magnetic Materials and Devices, and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- University of Chinese Academy of Sciences, 19 A Yuquan Rd, Shijingshan District, Beijing, 100049, China
| | - Wei Li
- CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, Chinese Academy of Sciences, Ningbo Institute of Material Technology and Engineering, Ningbo, 315201, China
| | - Guowei Li
- CAS Key Laboratory of Magnetic Materials and Devices, and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- University of Chinese Academy of Sciences, 19 A Yuquan Rd, Shijingshan District, Beijing, 100049, China
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4
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Su M, Zhang Y, Liu G, Jiang H, Lin Y, Ding Y, Wu Q, Wei W, Wang X, Wu T, Tao K, Chen C, Xie E, Zhang Z. Optimizing Surface State Electrons of Topological Semi-Metal by Atomic Doping for Enhanced Hydrogen Evolution Reaction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2403710. [PMID: 38884192 DOI: 10.1002/smll.202403710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Indexed: 06/18/2024]
Abstract
Topological materials carrying topological surface states (TSSs) have extraordinary carrier mobility and robustness, which provide a new platform for searching for efficient hydrogen evolution reaction (HER) electrocatalysts. However, the majority of these TSSs originate from the sp band of topological quantum catalysts rather than the d band. Here, based on the density functional theory calculation, it is reported a topological semimetal Pd3Sn carrying TSSs mainly derived from d orbital and proposed that optimizing surface state electrons of Pd3Sn by introduction heteroatoms (Ni) can promote hybridization between hydrogen atoms and electrons, thereby reducing the Gibbs free energy (ΔGH) of adsorbed hydrogen and improving its HER performance. Moreover, this is well verified by electrocatalytic experiment results, the Ni-doped Pd3Sn (Ni0.1Pd2.9Sn) show much lower overpotential (-29 mV vs RHE) and Tafel slope (17 mV dec-1) than Pd3Sn (-39 mV vs RHE, 25 mV dec-1) at a current density of 10 mA cm-2. Significantly, the Ni0.1Pd2.9Sn nanoparticles exhibit excellent stability for HER. The electrocatalytic activity of Ni0.1Pd2.9Sn nanoparticles is superior to that of commercial Pt. This work provides an accurate guide for manipulating surface state electrons to improve the HER performance of catalysts.
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Affiliation(s)
- Meixia Su
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Yuhao Zhang
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Guo Liu
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Haiqing Jiang
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Yuan Lin
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Yan Ding
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Qingfeng Wu
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Wei Wei
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Xinge Wang
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Tianyu Wu
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Kun Tao
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Changcheng Chen
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Erqing Xie
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Zhenxing Zhang
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
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5
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Krieger JA, Stolz S, Robredo I, Manna K, McFarlane EC, Date M, Pal B, Yang J, B Guedes E, Dil JH, Polley CM, Leandersson M, Shekhar C, Borrmann H, Yang Q, Lin M, Strocov VN, Caputo M, Watson MD, Kim TK, Cacho C, Mazzola F, Fujii J, Vobornik I, Parkin SSP, Bradlyn B, Felser C, Vergniory MG, Schröter NBM. Weyl spin-momentum locking in a chiral topological semimetal. Nat Commun 2024; 15:3720. [PMID: 38697958 PMCID: PMC11066003 DOI: 10.1038/s41467-024-47976-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 04/17/2024] [Indexed: 05/05/2024] Open
Abstract
Spin-orbit coupling in noncentrosymmetric crystals leads to spin-momentum locking - a directional relationship between an electron's spin angular momentum and its linear momentum. Isotropic orthogonal Rashba spin-momentum locking has been studied for decades, while its counterpart, isotropic parallel Weyl spin-momentum locking has remained elusive in experiments. Theory predicts that Weyl spin-momentum locking can only be realized in structurally chiral cubic crystals in the vicinity of Kramers-Weyl or multifold fermions. Here, we use spin- and angle-resolved photoemission spectroscopy to evidence Weyl spin-momentum locking of multifold fermions in the chiral topological semimetal PtGa. We find that the electron spin of the Fermi arc surface states is orthogonal to their Fermi surface contour for momenta close to the projection of the bulk multifold fermion at the Γ point, which is consistent with Weyl spin-momentum locking of the latter. The direct measurement of the bulk spin texture of the multifold fermion at the R point also displays Weyl spin-momentum locking. The discovery of Weyl spin-momentum locking may lead to energy-efficient memory devices and Josephson diodes based on chiral topological semimetals.
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Affiliation(s)
- Jonas A Krieger
- Max Planck Institut für Mikrostrukturphysik, Weinberg 2, 06120, Halle, Germany
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232, Villigen PSI, Switzerland
| | - Samuel Stolz
- Department of Physics, University of California, Berkeley, CA, USA
- nanotech@surfaces Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - Iñigo Robredo
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
- Donostia International Physics Center, 20018, Donostia - San Sebastian, Spain
| | - Kaustuv Manna
- Indian Institute of Technology-Delhi, Hauz Khas, New Delhi, 110 016, India
| | - Emily C McFarlane
- Max Planck Institut für Mikrostrukturphysik, Weinberg 2, 06120, Halle, Germany
| | - Mihir Date
- Max Planck Institut für Mikrostrukturphysik, Weinberg 2, 06120, Halle, Germany
| | - Banabir Pal
- Max Planck Institut für Mikrostrukturphysik, Weinberg 2, 06120, Halle, Germany
| | - Jiabao Yang
- Max Planck Institut für Mikrostrukturphysik, Weinberg 2, 06120, Halle, Germany
| | - Eduardo B Guedes
- Photon Science Division, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland
- Institut de Physique, École Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland
| | - J Hugo Dil
- Photon Science Division, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland
- Institut de Physique, École Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland
| | - Craig M Polley
- MAX IV Laboratory, Lund University, Fotongatan 2, 22484, Lund, Sweden
| | - Mats Leandersson
- MAX IV Laboratory, Lund University, Fotongatan 2, 22484, Lund, Sweden
| | - Chandra Shekhar
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Horst Borrmann
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Qun Yang
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Mao Lin
- Department of Physics, University of Illinois, Urbana-Champaign, USA
| | - Vladimir N Strocov
- Photon Science Division, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland
| | - Marco Caputo
- Photon Science Division, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland
| | - Matthew D Watson
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Timur K Kim
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Cephise Cacho
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Federico Mazzola
- Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, Trieste, I-34149, Italy
- Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, 30172, Venice, Italy
| | - Jun Fujii
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, I-34149, Trieste, Italy
| | - Ivana Vobornik
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, I-34149, Trieste, Italy
| | - Stuart S P Parkin
- Max Planck Institut für Mikrostrukturphysik, Weinberg 2, 06120, Halle, Germany
| | - Barry Bradlyn
- Department of Physics, University of Illinois, Urbana-Champaign, USA
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Maia G Vergniory
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
- Donostia International Physics Center, 20018, Donostia - San Sebastian, Spain
| | - Niels B M Schröter
- Max Planck Institut für Mikrostrukturphysik, Weinberg 2, 06120, Halle, Germany.
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6
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Lange G, Pottecher JDF, Robey C, Monserrat B, Peng B. Negative Refraction of Weyl Phonons at Twin Quartz Interfaces. ACS MATERIALS LETTERS 2024; 6:847-855. [PMID: 38455509 PMCID: PMC10915867 DOI: 10.1021/acsmaterialslett.3c00846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 03/09/2024]
Abstract
In Nature, α-quartz crystals frequently form contact twins, which are two adjacent crystals with the same chemical structure but different crystallographic orientation, sharing a common lattice plane. As α-quartz crystallizes in a chiral space group, such twinning can occur between enantiomorphs with the same handedness or with opposite handedness. Here, we use first-principles methods to investigate the effect of twinning and chirality on the bulk and surface phonon spectra, as well as on the topological properties of phonons in α-quartz. We demonstrate that, even though the dispersion appears identical for all twins along all high-symmetry lines and at all high-symmetry points in the Brillouin zone, the dispersions can be distinct at generic momenta for some twin structures. Furthermore, when the twinning occurs between different enantiomorphs, the charges of all Weyl nodal points flip, which leads to mirror symmetric isofrequency contours of the surface arcs on certain surfaces. We show that this allows negative refraction to occur at interfaces between certain twins of α-quartz.
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Affiliation(s)
- Gunnar
F. Lange
- Theory
of Condensed Matter Group, Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Juan D. F. Pottecher
- St.
Catharine’s College, University of
Cambridge, Trumpington Street, Cambridge CB2 1RL, United Kingdom
| | - Cameron Robey
- St.
John’s College, University of Cambridge, St John’s Street, Cambridge CB2 1TP, United Kingdom
| | - Bartomeu Monserrat
- Theory
of Condensed Matter Group, Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
- Department
of Materials Science and Metallurgy, University
of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Bo Peng
- Theory
of Condensed Matter Group, Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
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7
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Krempaský J, Šmejkal L, D'Souza SW, Hajlaoui M, Springholz G, Uhlířová K, Alarab F, Constantinou PC, Strocov V, Usanov D, Pudelko WR, González-Hernández R, Birk Hellenes A, Jansa Z, Reichlová H, Šobáň Z, Gonzalez Betancourt RD, Wadley P, Sinova J, Kriegner D, Minár J, Dil JH, Jungwirth T. Altermagnetic lifting of Kramers spin degeneracy. Nature 2024; 626:517-522. [PMID: 38356066 PMCID: PMC10866710 DOI: 10.1038/s41586-023-06907-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/28/2023] [Indexed: 02/16/2024]
Abstract
Lifted Kramers spin degeneracy (LKSD) has been among the central topics of condensed-matter physics since the dawn of the band theory of solids1,2. It underpins established practical applications as well as current frontier research, ranging from magnetic-memory technology3-7 to topological quantum matter8-14. Traditionally, LKSD has been considered to originate from two possible internal symmetry-breaking mechanisms. The first refers to time-reversal symmetry breaking by magnetization of ferromagnets and tends to be strong because of the non-relativistic exchange origin15. The second applies to crystals with broken inversion symmetry and tends to be comparatively weaker, as it originates from the relativistic spin-orbit coupling (SOC)16-19. A recent theory work based on spin-symmetry classification has identified an unconventional magnetic phase, dubbed altermagnetic20,21, that allows for LKSD without net magnetization and inversion-symmetry breaking. Here we provide the confirmation using photoemission spectroscopy and ab initio calculations. We identify two distinct unconventional mechanisms of LKSD generated by the altermagnetic phase of centrosymmetric MnTe with vanishing net magnetization20-23. Our observation of the altermagnetic LKSD can have broad consequences in magnetism. It motivates exploration and exploitation of the unconventional nature of this magnetic phase in an extended family of materials, ranging from insulators and semiconductors to metals and superconductors20,21, that have been either identified recently or perceived for many decades as conventional antiferromagnets21,24,25.
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Affiliation(s)
- J Krempaský
- Photon Science Division, Paul Scherrer Institut, Villigen, Switzerland.
| | - L Šmejkal
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz, Germany
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - S W D'Souza
- New Technologies Research Center, University of West Bohemia, Plzeň, Czech Republic
| | - M Hajlaoui
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University of Linz, Linz, Austria
| | - G Springholz
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University of Linz, Linz, Austria
| | - K Uhlířová
- Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
| | - F Alarab
- Photon Science Division, Paul Scherrer Institut, Villigen, Switzerland
| | - P C Constantinou
- Photon Science Division, Paul Scherrer Institut, Villigen, Switzerland
| | - V Strocov
- Photon Science Division, Paul Scherrer Institut, Villigen, Switzerland
| | - D Usanov
- Photon Science Division, Paul Scherrer Institut, Villigen, Switzerland
| | - W R Pudelko
- Photon Science Division, Paul Scherrer Institut, Villigen, Switzerland
- Physik-Institut, Universität Zürich, Zürich, Switzerland
| | - R González-Hernández
- Grupo de Investigación en Física Aplicada, Departamento de Física, Universidad del Norte, Barranquilla, Colombia
| | - A Birk Hellenes
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - Z Jansa
- New Technologies Research Center, University of West Bohemia, Plzeň, Czech Republic
| | - H Reichlová
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - Z Šobáň
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
| | | | - P Wadley
- School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
| | - J Sinova
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz, Germany
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - D Kriegner
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - J Minár
- New Technologies Research Center, University of West Bohemia, Plzeň, Czech Republic.
| | - J H Dil
- Photon Science Division, Paul Scherrer Institut, Villigen, Switzerland
- Institut de Physique, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - T Jungwirth
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic.
- School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom.
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8
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Niinomi H, Yamazaki T, Nada H, Hama T, Kouchi A, Oshikiri T, Nakagawa M, Kimura Y. Chiral Spinodal-like Ordering of Homoimmiscible Water at Interface between Water and Chiral Ice III. J Phys Chem Lett 2024; 15:659-664. [PMID: 38206160 DOI: 10.1021/acs.jpclett.3c03006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Diversity in structures of water endowed by a hydrogen-bonding network plays crucial roles in wide varieties of phenomena in nature. Chiral ordering of water molecules is an intriguing phenomenon from the viewpoint of bimolecular functions. However, experimental reports on chiral ordering have been limited to the water molecules interacting with biomolecules on the molecular scale. It remains unclear whether pure liquid water forms long-range chiral ordering without any interaction with biomolecules. Here, we show that chiral anisotropy can be observed in the macro/mesoscopic network pattern of an unknown water layer formed via spinodal phase separation-like dynamics at the interface between water and ice III with a chiral crystal structure. We named this unknown water homoimmiscible water. Our observations infer that the unknown water is a chiral liquid crystal. This possibility opens new avenues for a wide variety of research fields such as liquid polymorphism, biology, earth and planetary science, and so forth from the perspective of chirality.
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Affiliation(s)
- Hiromasa Niinomi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Tomoya Yamazaki
- Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo, Hokkaido 060-0819, Japan
| | - Hiroki Nada
- Graduate School of Engineering, Tottori University, 4-101 Koyama-Cho Minami, Tottori, Tottori 680-8552, Japan
| | - Tetsuya Hama
- Komaba Institute for Science, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
| | - Akira Kouchi
- Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo, Hokkaido 060-0819, Japan
| | - Tomoya Oshikiri
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
- Research Institute for Electronic Science, Hokkaido University, Kita-21, Nishi-10, Kita-ku, Sapporo, Hokkaido 001-0021, Japan
| | - Masaru Nakagawa
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Yuki Kimura
- Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo, Hokkaido 060-0819, Japan
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9
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Wang X, Yi C, Felser C. Chiral Quantum Materials: When Chemistry Meets Physics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2308746. [PMID: 38126622 DOI: 10.1002/adma.202308746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 12/01/2023] [Indexed: 12/23/2023]
Abstract
Chirality is a fundamental property of nature with relevance in biochemistry and physics, particularly in the field of catalysis. Understanding the mechanisms underlying chirality transfer is crucial for advancing the knowledge of chiral-related catalysis. Chiral quantum materials with intriguing chirality-dependent electronic properties, such as spin-orbital coupling (SOC) and exotic spin/orbital angular momentum (SAM/OAM), open novel avenues for linking solid-state topologies with chiral catalysis. In this review, the growth of topological homochiral crystals (THCs) is described, and their applications in heterogeneous catalysis, including hydrogen evolution reaction (HER), oxygen electrocatalysis, and asymmetric catalysis are summarized. A possible link between chirality-dependent electronic properties and heterogeneous catalysis is discussed. Finally, existing challenges in this field are highlighted, and a brief outlook on the impact of THCs on the overarching chemical-physical research is presented.
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Affiliation(s)
- Xia Wang
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Changjiang Yi
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
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10
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Yang Q, Xiao J, Robredo I, Vergniory MG, Yan B, Felser C. Monopole-like orbital-momentum locking and the induced orbital transport in topological chiral semimetals. Proc Natl Acad Sci U S A 2023; 120:e2305541120. [PMID: 37983495 PMCID: PMC10691347 DOI: 10.1073/pnas.2305541120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 10/20/2023] [Indexed: 11/22/2023] Open
Abstract
The interplay between chirality and topology nurtures many exotic electronic properties. For instance, topological chiral semimetals display multifold chiral fermions that manifest nontrivial topological charge and spin texture. They are an ideal playground for exploring chirality-driven exotic physical phenomena. In this work, we reveal a monopole-like orbital-momentum locking texture on the three-dimensional Fermi surfaces of topological chiral semimetals with B20 structures (e.g., RhSi and PdGa). This orbital texture enables a large orbital Hall effect (OHE) and a giant orbital magnetoelectric (OME) effect in the presence of current flow. Different enantiomers exhibit the same OHE which can be converted to the spin Hall effect by spin-orbit coupling in materials. In contrast, the OME effect is chirality-dependent and much larger than its spin counterpart. Our work reveals the crucial role of orbital texture for understanding OHE and OME effects in topological chiral semimetals and paves the path for applications in orbitronics, spintronics, and enantiomer recognition.
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Affiliation(s)
- Qun Yang
- Max Planck Institute for Chemical Physics of Solids, Dresden01187, Germany
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Jiewen Xiao
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Iñigo Robredo
- Max Planck Institute for Chemical Physics of Solids, Dresden01187, Germany
- Donostia International Physics Center, Donostia-San Sebastian20018, Spain
| | - Maia G. Vergniory
- Max Planck Institute for Chemical Physics of Solids, Dresden01187, Germany
- Donostia International Physics Center, Donostia-San Sebastian20018, Spain
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, Dresden01187, Germany
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11
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Niu C, Qiu G, Wang Y, Tan P, Wang M, Jian J, Wang H, Wu W, Ye PD. Tunable Chirality-Dependent Nonlinear Electrical Responses in 2D Tellurium. NANO LETTERS 2023; 23:8445-8453. [PMID: 37677143 DOI: 10.1021/acs.nanolett.3c01797] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
Tellurium (Te) is an elemental semiconductor with a simple chiral crystal structure. Te in a two-dimensional (2D) form synthesized by a solution-based method shows excellent electrical, optical, and thermal properties. In this work, the chirality of hydrothermally grown 2D Te is identified and analyzed by hot sulfuric acid etching and high-angle tilted high-resolution scanning transmission electron microscopy. The gate-tunable nonlinear electrical responses, including the nonreciprocal electrical transport in the longitudinal direction and the nonlinear planar Hall effect in the transverse direction, are observed in 2D Te under a magnetic field. Moreover, the nonlinear electrical responses have opposite signs in left- and right-handed 2D Te due to the opposite spin polarizations ensured by the chiral symmetry. The fundamental relationship between the spin-orbit coupling and the crystal symmetry in two enantiomers provides a viable platform for realizing chirality-based electronic devices by introducing the degree of freedom of chirality into electron transport.
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Affiliation(s)
- Chang Niu
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Gang Qiu
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Yixiu Wang
- School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Pukun Tan
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Mingyi Wang
- School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jie Jian
- School of Materials Science and Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Haiyan Wang
- School of Materials Science and Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Wenzhuo Wu
- School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Peide D Ye
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
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12
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Zhang T, Huang Z, Pan Z, Du L, Zhang G, Murakami S. Weyl Phonons in Chiral Crystals. NANO LETTERS 2023; 23:7561-7567. [PMID: 37530581 DOI: 10.1021/acs.nanolett.3c02132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
Chirality is an indispensable concept that pervades fundamental science and nature, manifesting itself in diverse forms, e.g., quasiparticles, and crystal structures. Of particular interest are Weyl phonons carrying specific Chern numbers and chiral phonons doing circular motions. Up to now, they have been studied independently and the interpretations of chirality seem to be different in these two concepts, impeding our understanding. Here, we demonstrate that they are entangled in chiral crystals. Employing a typical chiral crystal of elementary tellurium (Te) as a case study, we expound on the intrinsic relationship between Chern number of Weyl phonons and pseudoangular momentum (PAM, lph) of chiral phonons. We propose Raman scattering as a new technique to demonstrate the existence of Weyl phonons in Te, by detecting the chirality-induced energy splitting between the two constituent chiral phonon branches for Weyl phonons. Moreover, we also observe the obstructed phonon surface states for the first time.
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Affiliation(s)
- Tiantian Zhang
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhiheng Huang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zitian Pan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Luojun Du
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Guangyu Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan 523808, China
| | - Shuichi Murakami
- Department of Physics, Tokyo Institute of Technology, Okayama, Meguro-ku, Tokyo 152-8551, Japan
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13
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Strocov VN, Lev LL, Alarab F, Constantinou P, Wang X, Schmitt T, Stock TJZ, Nicolaï L, Očenášek J, Minár J. High-energy photoemission final states beyond the free-electron approximation. Nat Commun 2023; 14:4827. [PMID: 37563126 PMCID: PMC10415355 DOI: 10.1038/s41467-023-40432-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 07/26/2023] [Indexed: 08/12/2023] Open
Abstract
Three-dimensional (3D) electronic band structure is fundamental for understanding a vast diversity of physical phenomena in solid-state systems, including topological phases, interlayer interactions in van der Waals materials, dimensionality-driven phase transitions, etc. Interpretation of ARPES data in terms of 3D electron dispersions is commonly based on the free-electron approximation for the photoemission final states. Our soft-X-ray ARPES data on Ag metal reveals, however, that even at high excitation energies the final states can be a way more complex, incorporating several Bloch waves with different out-of-plane momenta. Such multiband final states manifest themselves as a complex structure and added broadening of the spectral peaks from 3D electron states. We analyse the origins of this phenomenon, and trace it to other materials such as Si and GaN. Our findings are essential for accurate determination of the 3D band structure over a wide range of materials and excitation energies in the ARPES experiment.
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Affiliation(s)
- V N Strocov
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland.
| | - L L Lev
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
- Moscow Institute of Physics and Technology, 141701, Dolgoprudny, Russia
| | - F Alarab
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - P Constantinou
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - X Wang
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - T Schmitt
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - T J Z Stock
- London Centre for Nanotechnology, University College London, London, WC1H 0AH, UK
| | - L Nicolaï
- University of West Bohemia, New Technologies Research Centre, 301 00, Plzeň, Czech Republic
| | - J Očenášek
- University of West Bohemia, New Technologies Research Centre, 301 00, Plzeň, Czech Republic
| | - J Minár
- University of West Bohemia, New Technologies Research Centre, 301 00, Plzeň, Czech Republic.
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14
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Nguyen DHM, Devescovi C, Nguyen DX, Nguyen HS, Bercioux D. Fermi Arc Reconstruction in Synthetic Photonic Lattice. PHYSICAL REVIEW LETTERS 2023; 131:053602. [PMID: 37595227 DOI: 10.1103/physrevlett.131.053602] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 06/29/2023] [Indexed: 08/20/2023]
Abstract
The chiral surface states of Weyl semimetals have an open Fermi surface called a Fermi arc. At the interface between two Weyl semimetals, these Fermi arcs are predicted to hybridize and alter their connectivity. In this Letter, we numerically study a one-dimensional (1D) dielectric trilayer grating where the relative displacements between adjacent layers play the role of two synthetic momenta. The lattice emulates 3D crystals without time-reversal symmetry, including Weyl semimetal, nodal line semimetal, and Chern insulator. Besides showing the phase transition between Weyl semimetal and Chern insulator at telecom wavelength, this system allows us to observe the Fermi arc reconstruction between two Weyl semimetals, confirming the theoretical predictions.
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Affiliation(s)
- D-H-Minh Nguyen
- Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain
| | - Chiara Devescovi
- Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain
| | - Dung Xuan Nguyen
- Center for Theoretical Physics of Complex Systems, Institute for Basic Science (IBS), Daejeon, 34126, Republic of Korea
| | - Hai Son Nguyen
- Université Lyon, Ecole Centrale de Lyon, CNRS, INSA Lyon, Université Claude Bernard Lyon 1, CPE Lyon, CNRS, INL, UMR5270, Ecully 69130, France
- Institut Universitaire de France (IUF), F-75231 Paris, France
| | - Dario Bercioux
- Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain
- IKERBASQUE, Basque Foundation for Science, Euskadi Plaza, 5, 48009 Bilbao, Spain
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15
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Niu C, Huang S, Ghosh N, Tan P, Wang M, Wu W, Xu X, Ye PD. Tunable Circular Photogalvanic and Photovoltaic Effect in 2D Tellurium with Different Chirality. NANO LETTERS 2023; 23:3599-3606. [PMID: 37057864 DOI: 10.1021/acs.nanolett.3c00780] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Chirality arises from the asymmetry of materials, where two counterparts are the mirror image of each other. The interaction between circular-polarized light and quantum materials is enhanced in chiral space groups due to the structural chirality. Tellurium (Te) possesses the simplest chiral crystal structure, with Te atoms covalently bonded into a spiral atomic chain (left- or right-handed) with a periodicity of 3. Here, we investigate the tunable circular photoelectric responses in 2D Te field-effect transistors with different chirality, including the longitudinal circular photogalvanic effect induced by the radial spin texture (electron-spin polarization parallel to the electron momentum direction) and the circular photovoltaic effect induced by the chiral crystal structure (helical Te atomic chains). Our work demonstrates the controllable manipulation of the chirality degree of freedom in materials.
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Affiliation(s)
- Chang Niu
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Shouyuan Huang
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Neil Ghosh
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Pukun Tan
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Mingyi Wang
- School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Wenzhuo Wu
- School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Xianfan Xu
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Peide D Ye
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
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16
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Mathur N, Yuan F, Cheng G, Kaushik S, Robredo I, Vergniory MG, Cano J, Yao N, Jin S, Schoop LM. Atomically Sharp Internal Interface in a Chiral Weyl Semimetal Nanowire. NANO LETTERS 2023; 23:2695-2702. [PMID: 36920080 DOI: 10.1021/acs.nanolett.2c05100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Internal interfaces in Weyl semimetals (WSMs) are predicted to host distinct topological features that are different from the commonly studied external interfaces (crystal-to-vacuum boundaries). However, the lack of atomically sharp and crystallographically oriented internal interfaces in WSMs makes it difficult to experimentally investigate topological states buried inside the material. Here, we study a unique internal interface known as merohedral twin boundary in chemically synthesized single-crystal nanowires (NWs) of CoSi, a chiral WSM of space group P213 (No. 198). Scanning transmission electron microscopy reveals that this internal interface is a (001) twin plane which connects two enantiomeric counterparts at an atomically sharp interface with inversion twinning. Ab initio calculations show localized internal Fermi arcs at the (001) twin plane that can be clearly distinguished from both external Fermi arcs and bulk states. These merohedrally twinned CoSi NWs provide an ideal platform to explore topological properties associated with internal interfaces in WSMs.
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Affiliation(s)
- Nitish Mathur
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Fang Yuan
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Guangming Cheng
- Princeton Institute for Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
| | - Sahal Kaushik
- Nordita, Stockholm University and KTH Royal Institute of Technology, Hannes Alfvéns väg 12, SE-106 91 Stockholm, Sweden
| | - Iñigo Robredo
- Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain
- Max Planck Institute for Chemical Physics of Solids, Dresden D-01187, Germany
| | - Maia G Vergniory
- Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain
- Max Planck Institute for Chemical Physics of Solids, Dresden D-01187, Germany
| | - Jennifer Cano
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, United States
- Center for Computational Quantum Physics, Flatiron Institute, New York, New York 10010, United States
| | - Nan Yao
- Princeton Institute for Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
| | - Song Jin
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Leslie M Schoop
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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17
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Charge instability of topological Fermi arcs in chiral crystal CoSi. Sci Bull (Beijing) 2023; 68:165-172. [PMID: 36653217 DOI: 10.1016/j.scib.2023.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 12/09/2022] [Accepted: 12/31/2022] [Indexed: 01/06/2023]
Abstract
Topological boundary states emerged at the spatial boundary between topological non-trivial and trivial phases, are usually gapless, or commonly referred as metallic states. For example, the surface state of a topological insulator is a gapless Dirac state. These metallic topological boundary states are typically well described by non-interacting fermions. However, the behavior of topological boundary states with significant electron-electron interactions, which could turn the gapless boundary states into gapped ordered states, e.g., density wave states or superconducting states, is of great interest theoretically, but is still lacking evidence experimentally. Here, we report the observation of incommensurable charge density wave (CDW) formed on the topological boundary states driven by the electron-electron interactions on the (001) surface of CoSi. The wavevector of CDW varies as the temperature changes, which coincides with the evolution of topological surface Fermi arcs with temperature. The orientation of the CDW phase is determined by the chirality of the Fermi arcs, which indicates a direct association between CDW and Fermi arcs. Our finding will stimulate the search of more interactions-driven ordered states, such as superconductivity and magnetism, on the boundaries of topological materials.
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18
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Chen Q, Chen F, Pan Y, Cui C, Yan Q, Zhang L, Gao Z, Yang SA, Yu ZM, Chen H, Zhang B, Yang Y. Discovery of a maximally charged Weyl point. Nat Commun 2022; 13:7359. [PMID: 36450711 PMCID: PMC9712526 DOI: 10.1038/s41467-022-34978-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/14/2022] [Indexed: 12/03/2022] Open
Abstract
The hypothetical Weyl particles in high-energy physics have been discovered in three-dimensional crystals as collective quasiparticle excitations near two-fold degenerate Weyl points. Such momentum-space Weyl particles carry quantised chiral charges, which can be measured by counting the number of Fermi arcs emanating from the corresponding Weyl points. It is known that merging unit-charged Weyl particles can create new ones with more charges. However, only very recently has it been realised that there is an upper limit - the maximal charge number that a two-fold Weyl point can host is four - achievable only in crystals without spin-orbit coupling. Here, we report the experimental realisation of such a maximally charged Weyl point in a three-dimensional photonic crystal. The four charges support quadruple-helicoid Fermi arcs, forming an unprecedented topology of two non-contractible loops in the surface Brillouin zone. The helicoid Fermi arcs also exhibit the long-pursued type-II van Hove singularities that can reside at arbitrary momenta. This discovery reveals a type of maximally charged Weyl particles beyond conventional topological particles in crystals.
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Affiliation(s)
- Qiaolu Chen
- Interdisciplinary Centre for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Centre, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
| | - Fujia Chen
- Interdisciplinary Centre for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Centre, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
| | - Yuang Pan
- Interdisciplinary Centre for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Centre, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
| | - Chaoxi Cui
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, 100081, China
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing, 100081, China
| | - Qinghui Yan
- Interdisciplinary Centre for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Centre, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
| | - Li Zhang
- Interdisciplinary Centre for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Centre, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
| | - Zhen Gao
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Shengyuan A Yang
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore, 487372, Singapore
| | - Zhi-Ming Yu
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, 100081, China.
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing, 100081, China.
| | - Hongsheng Chen
- Interdisciplinary Centre for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Zhejiang University, Hangzhou, 310027, China.
- International Joint Innovation Centre, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China.
- Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China.
| | - Baile Zhang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
| | - Yihao Yang
- Interdisciplinary Centre for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Zhejiang University, Hangzhou, 310027, China.
- International Joint Innovation Centre, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China.
- Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China.
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19
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Schwarze BV, Uhlarz M, Hornung J, Chattopadhyay S, Manna K, Shekhar C, Felser C, Wosnitza J. Fermi surface of the chiral topological semimetal PtGa. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:425502. [PMID: 35940168 DOI: 10.1088/1361-648x/ac87e5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
PtGa is a topological semimetal with giant spin-split Fermi arcs. Here, we report on angular-dependent de Haas-van Alphen (dHvA) measurements combined with band-structure calculations to elucidate the details of the bulk Fermi surface of PtGa. The strong spin-orbit coupling leads to eight bands crossing the Fermi energy that form a multitude of Fermi surfaces with closed extremal orbits and results in very rich dHvA spectra. The large number of experimentally observed dHvA frequencies make the assignment to the equally large number of calculated dHvA orbits challenging. Nevertheless, we find consistency between experiment and calculations verifying the topological character with maximal Chern number of the spin-split Fermi surface.
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Affiliation(s)
- B V Schwarze
- Hochfeld-Magnetlabor Dresden (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, 01062 Dresden, Germany
| | - M Uhlarz
- Hochfeld-Magnetlabor Dresden (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - J Hornung
- Hochfeld-Magnetlabor Dresden (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, 01062 Dresden, Germany
| | - S Chattopadhyay
- Hochfeld-Magnetlabor Dresden (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - K Manna
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - C Shekhar
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - C Felser
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - J Wosnitza
- Hochfeld-Magnetlabor Dresden (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, 01062 Dresden, Germany
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20
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Huber N, Alpin K, Causer GL, Worch L, Bauer A, Benka G, Hirschmann MM, Schnyder AP, Pfleiderer C, Wilde MA. Network of Topological Nodal Planes, Multifold Degeneracies, and Weyl Points in CoSi. PHYSICAL REVIEW LETTERS 2022; 129:026401. [PMID: 35867447 DOI: 10.1103/physrevlett.129.026401] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 01/26/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
We showcase the importance of global band topology in a study of the Weyl semimetal CoSi as a representative of chiral space group (SG) 198. We identify a network of band crossings comprising topological nodal planes, multifold degeneracies, and Weyl points consistent with the fermion doubling theorem. To confirm these findings, we combined the general analysis of the band topology of SG 198 with Shubnikov-de Haas oscillations and material-specific calculations of the electronic structure and Berry curvature. The observation of two nearly dispersionless Shubnikov-de Haas frequency branches provides unambiguous evidence of four Fermi surface sheets at the R point that reflect the symmetry-enforced orthogonality of the underlying wave functions at the intersections with the nodal planes. Hence, irrespective of the spin-orbit coupling strength, SG 198 features always six- and fourfold degenerate crossings at R and Γ that are intimately connected to the topological charges distributed across the network.
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Affiliation(s)
- Nico Huber
- Physik Department, Technische Universität München, D-85748 Garching, Germany
| | - Kirill Alpin
- Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - Grace L Causer
- Physik Department, Technische Universität München, D-85748 Garching, Germany
| | - Lukas Worch
- Physik Department, Technische Universität München, D-85748 Garching, Germany
| | - Andreas Bauer
- Physik Department, Technische Universität München, D-85748 Garching, Germany
| | - Georg Benka
- Physik Department, Technische Universität München, D-85748 Garching, Germany
| | - Moritz M Hirschmann
- Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - Andreas P Schnyder
- Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - Christian Pfleiderer
- Physik Department, Technische Universität München, D-85748 Garching, Germany
- MCQST, Technische Universität München, D-85748 Garching, Germany
- Centre for Quantum Engineering (ZQE), Technische Universität München, D-85748 Garching, Germany
| | - Marc A Wilde
- Physik Department, Technische Universität München, D-85748 Garching, Germany
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21
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Guo C, Hu L, Putzke C, Diaz J, Huang X, Manna K, Fan FR, Shekhar C, Sun Y, Felser C, Liu C, Bernevig BA, Moll PJW. Quasi-symmetry protected topology in a semi-metal. NATURE PHYSICS 2022; 18:813-818. [PMID: 35855397 PMCID: PMC7613062 DOI: 10.1038/s41567-022-01604-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 03/31/2022] [Indexed: 05/19/2023]
Abstract
The crystal symmetry of a material dictates the type of topological band structures it may host, and therefore symmetry is the guiding principle to find topological materials. Here we introduce an alternative guiding principle, which we call 'quasi-symmetry'. This is the situation where a Hamiltonian has an exact symmetry at lower-order that is broken by higher-order perturbation terms. This enforces finite but parametrically small gaps at some low-symmetry points in momentum space. Untethered from the restraints of symmetry, quasi-symmetries eliminate the need for fine-tuning as they enforce that sources of large Berry curvature will occur at arbitrary chemical potentials. We demonstrate that a quasi-symmetry in the semi-metal CoSi stabilizes gaps below 2 meV over a large near-degenerate plane that can be measured in the quantum oscillation spectrum. The application of in-plane strain breaks the crystal symmetry and gaps the degenerate point, observable by new magnetic breakdown orbits. The quasi-symmetry, however, does not depend on spatial symmetries and hence transmission remains fully coherent. These results demonstrate a class of topological materials with increased resilience to perturbations such as strain-induced crystalline symmetry breaking, which may lead to robust topological applications as well as unexpected topology beyond the usual space group classifications.
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Affiliation(s)
- Chunyu Guo
- Laboratory of Quantum Materials (QMAT), Institute of Materials (IMX), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Lunhui Hu
- Department of Physics, The Pennsylvania State University, University Park, PA, USA
| | - Carsten Putzke
- Laboratory of Quantum Materials (QMAT), Institute of Materials (IMX), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - Jonas Diaz
- Laboratory of Quantum Materials (QMAT), Institute of Materials (IMX), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Xiangwei Huang
- Laboratory of Quantum Materials (QMAT), Institute of Materials (IMX), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Kaustuv Manna
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Feng-Ren Fan
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Chandra Shekhar
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Yan Sun
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Chaoxing Liu
- Department of Physics, The Pennsylvania State University, University Park, PA, USA
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - B. Andrei Bernevig
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
- Donostia International Physics Center,P. Manuel de Lardizabal 4, 20018 Donostia-San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Philip J. W. Moll
- Laboratory of Quantum Materials (QMAT), Institute of Materials (IMX), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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22
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Li G, Yang H, Jiang P, Wang C, Cheng Q, Tian S, Han G, Shen C, Lin X, Lei H, Ji W, Wang Z, Gao HJ. Chirality locking charge density waves in a chiral crystal. Nat Commun 2022; 13:2914. [PMID: 35614101 PMCID: PMC9133074 DOI: 10.1038/s41467-022-30612-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 05/05/2022] [Indexed: 11/13/2022] Open
Abstract
In Weyl semimetals, charge density wave (CDW) order can spontaneously break the chiral symmetry, gap out the Weyl nodes, and drive the material into the axion insulating phase. Investigations have however been limited since CDWs are rarely seen in Weyl semimetals. Here, using scanning tunneling microscopy/spectroscopy (STM/S), we report the discovery of a novel unidirectional CDW order on the (001) surface of chiral crystal CoSi - a unique Weyl semimetal with unconventional chiral fermions. The CDW is incommensurate with both lattice momentum and crystalline symmetry directions, and exhibits an intra unit cell π phase shift in the layer stacking direction. The tunneling spectrum shows a particle-hole asymmetric V-shaped energy gap around the Fermi level that modulates spatially with the CDW wave vector. Combined with first-principle calculations, we identify that the CDW is locked to the crystal chirality and is related by a mirror reflection between the two enantiomers of the chiral crystal. Our findings reveal a novel correlated topological quantum state in chiral CoSi crystals and raise the potential for exploring the unprecedented physical behaviors of unconventional chiral fermions.
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Affiliation(s)
- Geng Li
- Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
- CAS Center for Excellent in Topological Quantum Computation, University of Chinese Academy of Sciences, 100190, Beijing, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, PR China
| | - Haitao Yang
- Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Peijie Jiang
- Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Cong Wang
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, 100872, Beijing, PR China
| | - Qiuzhen Cheng
- Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Shangjie Tian
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, 100872, Beijing, PR China
| | - Guangyuan Han
- Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Chengmin Shen
- Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Xiao Lin
- Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Hechang Lei
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, 100872, Beijing, PR China.
| | - Wei Ji
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, 100872, Beijing, PR China.
| | - Ziqiang Wang
- Department of Physics, Boston College, Chestnut Hill, MA, USA.
| | - Hong-Jun Gao
- Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.
- School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China.
- CAS Center for Excellent in Topological Quantum Computation, University of Chinese Academy of Sciences, 100190, Beijing, China.
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, PR China.
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23
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Won J, Kim S, Gutierrez‐Amigo M, Bettler S, Lee B, Son J, Won Noh T, Errea I, Vergniory MG, Abbamonte P, Mahmood F, Shoemaker DP. Transport and optical properties of the chiral semiconductor Ag
3
AuSe
2. Z Anorg Allg Chem 2022. [DOI: 10.1002/zaac.202200055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Juyeon Won
- Department of Materials Science and Engineering and Materials Research Laboratory University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Soyeun Kim
- Department of Physics University of Illinois at Urbana-Champaign Urbana 61801 IL USA
- Materials Research Laboratory University of Illinois at Urbana-Champaign Urbana 61801 IL USA
| | - Martin Gutierrez‐Amigo
- Department of Physics University of the Basque Country (UPV/EHU) Apartado 644 48080 Bilbao Spain
- Centro de Física de Materiales (CSIC-UPV/EHU) Manuel de Lardizabal Pasealekua 5 20018 Donostia/San Sebastián Spain
| | - Simon Bettler
- Department of Physics University of Illinois at Urbana-Champaign Urbana 61801 IL USA
- Materials Research Laboratory University of Illinois at Urbana-Champaign Urbana 61801 IL USA
| | - Bumjoo Lee
- Center for Correlated Electron Systems Institute for Basic Science Seoul 08826 Republic of Korea
- Department of Physics and Astronomy Seoul National University Seoul 08826 Republic of Korea
| | - Jaeseok Son
- Center for Correlated Electron Systems Institute for Basic Science Seoul 08826 Republic of Korea
- Department of Physics and Astronomy Seoul National University Seoul 08826 Republic of Korea
| | - Tae Won Noh
- Center for Correlated Electron Systems Institute for Basic Science Seoul 08826 Republic of Korea
- Department of Physics and Astronomy Seoul National University Seoul 08826 Republic of Korea
| | - Ion Errea
- Centro de Física de Materiales (CSIC-UPV/EHU) Manuel de Lardizabal Pasealekua 5 20018 Donostia/San Sebastián Spain
- Donostia International Physics Center P. Manuel de Lardizabal 4 20018 Donostia-San Sebastian Spain
- Fisika Aplikatua Saila, Gipuzkoako Ingeniaritza Eskola University of the Basque Country (UPV/EHU) Europa Plaza 1 20018 Donostia/San Sebastián Spain
| | - Maia G. Vergniory
- Donostia International Physics Center P. Manuel de Lardizabal 4 20018 Donostia-San Sebastian Spain
- Max Planck Institute for Chemical Physics of Solids 01187 Dresden Germany
| | - Peter Abbamonte
- Department of Physics University of Illinois at Urbana-Champaign Urbana 61801 IL USA
- Materials Research Laboratory University of Illinois at Urbana-Champaign Urbana 61801 IL USA
| | - Fahad Mahmood
- Department of Physics University of Illinois at Urbana-Champaign Urbana 61801 IL USA
- Materials Research Laboratory University of Illinois at Urbana-Champaign Urbana 61801 IL USA
| | - Daniel P. Shoemaker
- Department of Materials Science and Engineering and Materials Research Laboratory University of Illinois at Urbana-Champaign Urbana IL 61801 USA
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24
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Vergniory MG, Wieder BJ, Elcoro L, Parkin SSP, Felser C, Bernevig BA, Regnault N. All topological bands of all nonmagnetic stoichiometric materials. Science 2022; 376:eabg9094. [PMID: 35587971 DOI: 10.1126/science.abg9094] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Topological quantum chemistry and symmetry-based indicators have facilitated large-scale searches for materials with topological properties at the Fermi energy (EF). We report the implementation of a publicly accessible catalog of stable and fragile topology in all of the bands both at and away from EF in the 96,196 processable entries in the Inorganic Crystal Structure Database. Our calculations, which represent the completion of the symmetry-indicated band topology of known nonmagnetic materials, have enabled the discovery of repeat-topological and supertopological materials, including rhombohedral bismuth and Bi2Mg3. We find that 52.65% of all materials are topological at EF, roughly two-thirds of bands across all materials exhibit symmetry-indicated stable topology, and 87.99% of all materials contain at least one stable or fragile topological band.
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Affiliation(s)
- Maia G Vergniory
- Donostia International Physics Center, 20018 Donostia-San Sebastian, Spain.,IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.,Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Benjamin J Wieder
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Physics, Northeastern University, Boston, MA 02115, USA.,Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Luis Elcoro
- Department of Condensed Matter Physics, University of the Basque Country UPV/EHU, 48080 Bilbao, Spain
| | - Stuart S P Parkin
- Max Planck Institute of Microstructure Physics, 06120 Halle, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - B Andrei Bernevig
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Nicolas Regnault
- Department of Physics, Princeton University, Princeton, NJ 08544, USA.,Laboratoire de Physique de l'École Normale Supérieure, PSL University, CNRS, Sorbonne Université, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
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25
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Stolz S, Danese M, Di Giovannantonio M, Urgel JI, Sun Q, Kinikar A, Bommert M, Mishra S, Brune H, Gröning O, Passerone D, Widmer R. Asymmetric Elimination Reaction on Chiral Metal Surfaces. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2104481. [PMID: 34613643 DOI: 10.1002/adma.202104481] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 09/19/2021] [Indexed: 06/13/2023]
Abstract
The production of enantiopure materials and molecules is of uttermost relevance in research and industry in numerous contexts, ranging from nonlinear optics to asymmetric synthesis. In the context of the latter, dehalogenation, which is an essential reaction step for a broad class of chemical reactions, is investigated; specifically, dehalogenation of prochiral 5-bromo-7-methylbenz(a)anthracene (BMA) on prototypical, chiral, intermetallic PdGa{111} surfaces under ultrahigh vacuum conditions. Asymmetric halogen elimination is demonstrated by combining temperature-programmed X-ray photoelectron spectroscopy, scanning probe microscopy, and density functional theory. On the PdGa{111} surfaces, the difference in debromination temperatures for the two BMA surface enantiomers amounts up to an unprecedented 46 K. The significant dependence of the dehalogenation temperature of the BMA surface enantiomers on the atomic termination of the PdGa{111} surfaces implies that the ensemble effect is pronounced in this reaction step. These findings evidence enantiospecific control and hence promote intrinsically chiral crystals for asymmetric on-surface synthesis.
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Affiliation(s)
- Samuel Stolz
- Nanotech@surfaces Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland
| | - Martina Danese
- Nanotech@surfaces Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Marco Di Giovannantonio
- Nanotech@surfaces Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - José I Urgel
- Nanotech@surfaces Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Qiang Sun
- Nanotech@surfaces Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Amogh Kinikar
- Nanotech@surfaces Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Max Bommert
- Nanotech@surfaces Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Shantanu Mishra
- Nanotech@surfaces Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Harald Brune
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland
| | - Oliver Gröning
- Nanotech@surfaces Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Daniele Passerone
- Nanotech@surfaces Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Roland Widmer
- Nanotech@surfaces Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
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26
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Chen G, Wang CM. Optical conductivities in triple fermions with different monopole charges. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 34:105303. [PMID: 34823239 DOI: 10.1088/1361-648x/ac3d55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 11/25/2021] [Indexed: 06/13/2023]
Abstract
We investigate the linear optical conductivities of the newly-discovered triple-component semimetals. Due to the exactly flat band, the optical conductivity relates to the transition between the zero band and the conduction band directly reflecting the band structure of the conduction electrons in contrast to the other materials. For the low-energy models with various monopole charges, the diagonal conductivities show strong anisotropy. Theω-dependence of interband conductivities for a general low-energy model is deduced. The real part of the interbandσxxalways linearly depends on the optical frequency, while the one ofσzzis proportional toω2/n-1. This can be a unique fingerprint of the monopole charge. For the lattice models, there also exists the optical anomalous Hall conductivity, where a sign change may appear. The characteristic frequencies of the kink structures are calculated, strictly. Our work will help us to establish the basic picture of linear optical response in topological triple-component semimetals and identify them from other materials.
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Affiliation(s)
- G Chen
- Department of Physics, Shanghai Normal University, Shanghai 200234, People's Republic of China
| | - C M Wang
- Department of Physics, Shanghai Normal University, Shanghai 200234, People's Republic of China
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27
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Ma Q, Grushin AG, Burch KS. Topology and geometry under the nonlinear electromagnetic spotlight. NATURE MATERIALS 2021; 20:1601-1614. [PMID: 34127824 DOI: 10.1038/s41563-021-00992-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
For many materials, a precise knowledge of their dispersion spectra is insufficient to predict their ordered phases and physical responses. Instead, these materials are classified by the geometrical and topological properties of their wavefunctions. A key challenge is to identify and implement experiments that probe or control these quantum properties. In this Review, we describe recent progress in this direction, focusing on nonlinear electromagnetic responses that arise directly from quantum geometry and topology. We give an overview of the field by discussing theoretical ideas, experiments and the materials that drive them. We conclude by discussing how these techniques can be combined with device architectures to uncover, probe and ultimately control quantum phases with emergent topological and correlated properties.
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Affiliation(s)
- Qiong Ma
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Adolfo G Grushin
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, France
| | - Kenneth S Burch
- Department of Physics, Boston College, Chestnut Hill, MA, USA.
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28
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29
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Bose A, Narayan A. Strain-induced topological charge control in multifold fermion systems. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:375002. [PMID: 34186528 DOI: 10.1088/1361-648x/ac0fa0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 06/29/2021] [Indexed: 06/13/2023]
Abstract
Multifold fermion systems feature free fermionic excitations, which have no counterparts in high-energy physics, and exhibit several unconventional properties. Using first-principles calculations, we predict that strain engineering can be used to control the distribution of topological charges in transition metal silicide candidate CoSi, hosting multifold fermions. We demonstrate that breaking the rotational symmetry of the system, by choosing a suitable strain, destroys the multifold fermions, and at the same time results in the creation of Weyl points. We introduce a low energy effective model to complement the results obtained from density functional calculations. Our findings suggest that strain-engineering is a useful approach to tune topological properties of multifold fermions.
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Affiliation(s)
- Anumita Bose
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Awadhesh Narayan
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
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30
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Ünzelmann M, Bentmann H, Figgemeier T, Eck P, Neu JN, Geldiyev B, Diekmann F, Rohlf S, Buck J, Hoesch M, Kalläne M, Rossnagel K, Thomale R, Siegrist T, Sangiovanni G, Sante DD, Reinert F. Momentum-space signatures of Berry flux monopoles in the Weyl semimetal TaAs. Nat Commun 2021; 12:3650. [PMID: 34131129 PMCID: PMC8206138 DOI: 10.1038/s41467-021-23727-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 05/12/2021] [Indexed: 11/16/2022] Open
Abstract
Since the early days of Dirac flux quantization, magnetic monopoles have been sought after as a potential corollary of quantized electric charge. As opposed to magnetic monopoles embedded into the theory of electromagnetism, Weyl semimetals (WSM) exhibit Berry flux monopoles in reciprocal parameter space. As a function of crystal momentum, such monopoles locate at the crossing point of spin-polarized bands forming the Weyl cone. Here, we report momentum-resolved spectroscopic signatures of Berry flux monopoles in TaAs as a paradigmatic WSM. We carried out angle-resolved photoelectron spectroscopy at bulk-sensitive soft X-ray energies (SX-ARPES) combined with photoelectron spin detection and circular dichroism. The experiments reveal large spin- and orbital-angular-momentum (SAM and OAM) polarizations of the Weyl-fermion states, resulting from the broken crystalline inversion symmetry in TaAs. Supported by first-principles calculations, our measurements image signatures of a topologically non-trivial winding of the OAM at the Weyl nodes and unveil a chirality-dependent SAM of the Weyl bands. Our results provide directly bulk-sensitive spectroscopic support for the non-trivial band topology in the WSM TaAs, promising to have profound implications for the study of quantum-geometric effects in solids. Weyl semimetals exhibit Berry flux monopoles in momentum-space, but direct experimental evidence has remained elusive. Here, the authors reveal topologically non-trivial winding of the orbital-angular-momentum at the Weyl nodes and a chirality-dependent spin-angular-momentum of the Weyl bands, as a direct signature of the Berry flux monopoles in TaAs.
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Affiliation(s)
- M Ünzelmann
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - H Bentmann
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany.
| | - T Figgemeier
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - P Eck
- Theoretische Physik I, Universität Würzburg, Würzburg, Germany
| | - J N Neu
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, USA.,National High Magnetic Field Laboratory, Tallahassee, FL, USA
| | - B Geldiyev
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - F Diekmann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
| | - S Rohlf
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
| | - J Buck
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
| | - M Hoesch
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - M Kalläne
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
| | - K Rossnagel
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany.,Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - R Thomale
- Theoretische Physik I, Universität Würzburg, Würzburg, Germany
| | - T Siegrist
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, USA.,National High Magnetic Field Laboratory, Tallahassee, FL, USA
| | - G Sangiovanni
- Theoretische Physik I, Universität Würzburg, Würzburg, Germany
| | - D Di Sante
- Theoretische Physik I, Universität Würzburg, Würzburg, Germany.,Department of Physics and Astronomy, University of Bologna, Bologna, Italy.,Center for Computational Quantum Physics, Flatiron Institute, New York, NY, USA
| | - F Reinert
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
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31
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Wilde MA, Dodenhöft M, Niedermayr A, Bauer A, Hirschmann MM, Alpin K, Schnyder AP, Pfleiderer C. Symmetry-enforced topological nodal planes at the Fermi surface of a chiral magnet. Nature 2021; 594:374-379. [PMID: 34135519 PMCID: PMC8208892 DOI: 10.1038/s41586-021-03543-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 04/09/2021] [Indexed: 02/05/2023]
Abstract
Despite recent efforts to advance spintronics devices and quantum information technology using materials with non-trivial topological properties, three key challenges are still unresolved1-9. First, the identification of topological band degeneracies that are generically rather than accidentally located at the Fermi level. Second, the ability to easily control such topological degeneracies. And third, the identification of generic topological degeneracies in large, multisheeted Fermi surfaces. By combining de Haas-van Alphen spectroscopy with density functional theory and band-topology calculations, here we show that the non-symmorphic symmetries10-17 in chiral, ferromagnetic manganese silicide (MnSi) generate nodal planes (NPs)11,12, which enforce topological protectorates (TPs) with substantial Berry curvatures at the intersection of the NPs with the Fermi surface (FS) regardless of the complexity of the FS. We predict that these TPs will be accompanied by sizeable Fermi arcs subject to the direction of the magnetization. Deriving the symmetry conditions underlying topological NPs, we show that the 1,651 magnetic space groups comprise 7 grey groups and 26 black-and-white groups with topological NPs, including the space group of ferromagnetic MnSi. Thus, the identification of symmetry-enforced TPs, which can be controlled with a magnetic field, on the FS of MnSi suggests the existence of similar properties-amenable for technological exploitation-in a large number of materials.
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Affiliation(s)
- Marc A Wilde
- Physik Department, Technische Universität München, Garching, Germany.
- Centre for QuantumEngineering (ZQE), Technische Universität München, Garching, Germany.
| | | | - Arthur Niedermayr
- Physik Department, Technische Universität München, Garching, Germany
| | - Andreas Bauer
- Physik Department, Technische Universität München, Garching, Germany
- Centre for QuantumEngineering (ZQE), Technische Universität München, Garching, Germany
| | | | - Kirill Alpin
- Max-Planck-Institute for Solid State Research, Stuttgart, Germany
| | | | - Christian Pfleiderer
- Physik Department, Technische Universität München, Garching, Germany.
- Centre for QuantumEngineering (ZQE), Technische Universität München, Garching, Germany.
- MCQST, Technische Universität München, Garching, Germany.
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32
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Asymmetric azide-alkyne Huisgen cycloaddition on chiral metal surfaces. Commun Chem 2021; 4:51. [PMID: 36697612 PMCID: PMC9814088 DOI: 10.1038/s42004-021-00488-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 03/09/2021] [Indexed: 01/28/2023] Open
Abstract
Achieving fundamental understanding of enantioselective heterogeneous synthesis is marred by the permanent presence of multitudinous arrangements of catalytically active sites in real catalysts. In this study, we address this issue by using structurally comparatively simple, well-defined, and chiral intermetallic PdGa{111} surfaces as catalytic substrates. We demonstrate the impact of chirality transfer and ensemble effect for the thermally activated azide-alkyne Huisgen cycloaddition between 3-(4-azidophenyl)propionic acid and 9-ethynylphenanthrene on these threefold symmetric intermetallic surfaces under ultrahigh vacuum conditions. Specifically, we encounter a dominating ensemble effect for this reaction as on the Pd3-terminated PdGa{111} surfaces no stable heterocoupled structures are created, while on the Pd1-terminated PdGa{111} surfaces, the cycloaddition proceeds regioselectively. Moreover, we observe chirality transfer from the substrate to the reaction products, as they are formed enantioselectively on the Pd1-terminated PdGa{111} surfaces. Our results evidence a determinant ensemble effect and the immense potential of PdGa as asymmetric heterogeneous catalyst.
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33
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Kumar N, Guin SN, Manna K, Shekhar C, Felser C. Topological Quantum Materials from the Viewpoint of Chemistry. Chem Rev 2021; 121:2780-2815. [PMID: 33151662 PMCID: PMC7953380 DOI: 10.1021/acs.chemrev.0c00732] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Indexed: 11/29/2022]
Abstract
Topology, a mathematical concept, has recently become a popular and truly transdisciplinary topic encompassing condensed matter physics, solid state chemistry, and materials science. Since there is a direct connection between real space, namely atoms, valence electrons, bonds, and orbitals, and reciprocal space, namely bands and Fermi surfaces, via symmetry and topology, classifying topological materials within a single-particle picture is possible. Currently, most materials are classified as trivial insulators, semimetals, and metals or as topological insulators, Dirac and Weyl nodal-line semimetals, and topological metals. The key ingredients for topology are certain symmetries, the inert pair effect of the outer electrons leading to inversion of the conduction and valence bands, and spin-orbit coupling. This review presents the topological concepts related to solids from the viewpoint of a solid-state chemist, summarizes techniques for growing single crystals, and describes basic physical property measurement techniques to characterize topological materials beyond their structure and provide examples of such materials. Finally, a brief outlook on the impact of topology in other areas of chemistry is provided at the end of the article.
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Affiliation(s)
- Nitesh Kumar
- Max Planck Institute for
Chemical
Physics of Solids, 01187 Dresden, Germany
| | - Satya N. Guin
- Max Planck Institute for
Chemical
Physics of Solids, 01187 Dresden, Germany
| | - Kaustuv Manna
- Max Planck Institute for
Chemical
Physics of Solids, 01187 Dresden, Germany
| | - Chandra Shekhar
- Max Planck Institute for
Chemical
Physics of Solids, 01187 Dresden, Germany
| | - Claudia Felser
- Max Planck Institute for
Chemical
Physics of Solids, 01187 Dresden, Germany
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34
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Narang P, Garcia CAC, Felser C. The topology of electronic band structures. NATURE MATERIALS 2021; 20:293-300. [PMID: 33139890 DOI: 10.1038/s41563-020-00820-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 09/03/2020] [Indexed: 05/05/2023]
Abstract
The study of topology as it relates to physical systems has rapidly accelerated during the past decade. Critical to the realization of new topological phases is an understanding of the materials that exhibit them and precise control of the materials chemistry. The convergence of new theoretical methods using symmetry indicators to identify topological material candidates and the synthesis of high-quality single crystals plays a key role, warranting discussion and context at an accessible level. This Perspective provides a broad introduction to topological phases, their known properties, and material realizations. We focus on recent work in topological Weyl and Dirac semimetals, with a particular emphasis on magnetic Weyl semimetals and emergent fermions in chiral crystals and their extreme responses to excitations, and we highlight areas where the field can continue to make remarkable discoveries. We further examine open questions and directions for the topological materials science community to pursue, including exploration of non-equilibrium properties of Weyl semimetals and cavity-dressed topological materials.
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Affiliation(s)
- Prineha Narang
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA.
| | - Christina A C Garcia
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Claudia Felser
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
- Max-Planck-Institut für Chemische Physik fester Stoffe, Dresden, Germany
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35
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Abstract
We present a theoretical study of the band structure and optical conductivity for the chiral multifold semimetal PdGa. We identify several characteristic features in the optical conductivity and provide their origins within the band structure. As experimental optical studies for the mentioned compound have not been reported, we contrast our results with the related compounds, RhSi and CoSi. We believe that the presented hallmarks will provide guidance to future experimental works.
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36
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Schröter NBM, Robredo I, Klemenz S, Kirby RJ, Krieger JA, Pei D, Yu T, Stolz S, Schmitt T, Dudin P, Kim TK, Cacho C, Schnyder A, Bergara A, Strocov VN, de Juan F, Vergniory MG, Schoop LM. Weyl fermions, Fermi arcs, and minority-spin carriers in ferromagnetic CoS 2. SCIENCE ADVANCES 2020; 6:eabd5000. [PMID: 33355138 PMCID: PMC11206217 DOI: 10.1126/sciadv.abd5000] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 11/05/2020] [Indexed: 06/12/2023]
Abstract
Magnetic Weyl semimetals are a newly discovered class of topological materials that may serve as a platform for exotic phenomena, such as axion insulators or the quantum anomalous Hall effect. Here, we use angle-resolved photoelectron spectroscopy and ab initio calculations to discover Weyl cones in CoS2, a ferromagnet with pyrite structure that has been long studied as a candidate for half-metallicity, which makes it an attractive material for spintronic devices. We directly observe the topological Fermi arc surface states that link the Weyl nodes, which will influence the performance of CoS2 as a spin injector by modifying its spin polarization at interfaces. In addition, we directly observe a minority-spin bulk electron pocket in the corner of the Brillouin zone, which proves that CoS2 cannot be a true half-metal.
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Affiliation(s)
- Niels B M Schröter
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland.
| | - Iñigo Robredo
- Donostia International Physics Center, 20018 Donostia-San Sebastian, Spain
- Condensed Matter Physics Department, University of the Basque Country UPV/EHU, 48080 Bilbao, Spain
| | - Sebastian Klemenz
- Department of Chemistry, Princeton University, Princeton, NJ 08540, USA
| | - Robert J Kirby
- Department of Chemistry, Princeton University, Princeton, NJ 08540, USA
| | - Jonas A Krieger
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
- Laboratorium für Festkörperphysik, ETH Zurich, CH-8093 Zurich, Switzerland
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Ding Pei
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK
| | - Tianlun Yu
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
- Advanced Materials Laboratory, State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Samuel Stolz
- EMPA, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
- Institute of Condensed Matter Physics, Station 3, EPFL, 1015 Lausanne, Switzerland
| | - Thorsten Schmitt
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | | | | | | | - Andreas Schnyder
- Max Planck Institute for Solid State Research, 70569, Stuttgart, Germany
| | - Aitor Bergara
- Donostia International Physics Center, 20018 Donostia-San Sebastian, Spain
- Condensed Matter Physics Department, University of the Basque Country UPV/EHU, 48080 Bilbao, Spain
- Centro de Física de Materiales, Centro Mixto CSIC -UPV/EHU, 20018 Donostia, Spain
| | - Vladimir N Strocov
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Fernando de Juan
- Donostia International Physics Center, 20018 Donostia-San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, 48013 Bilbao, Spain
| | - Maia G Vergniory
- Donostia International Physics Center, 20018 Donostia-San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, 48013 Bilbao, Spain
| | - Leslie M Schoop
- Department of Chemistry, Princeton University, Princeton, NJ 08540, USA.
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37
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Sengupta S, Lhachemi MNY, Garate I. Phonon Magnetochiral Effect of Band-Geometric Origin in Weyl Semimetals. PHYSICAL REVIEW LETTERS 2020; 125:146402. [PMID: 33064513 DOI: 10.1103/physrevlett.125.146402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 08/25/2020] [Accepted: 08/25/2020] [Indexed: 06/11/2023]
Abstract
The phonon magnetochiral effect consists of a nonreciprocity in the velocity or attenuation of acoustic waves when they propagate parallel and antiparallel to an external magnetic field. The first experimental observation of this effect in the bulk has been reported recently in a chiral magnet and ascribed to the hybridization between acoustic phonons and chiral magnons. Here, we predict a potentially measurable phonon magnetochiral effect of electronic origin in chiral Weyl semimetals. Caused by the Berry curvature and the orbital magnetic moment, this effect is enhanced for longitudinal phonons by the chiral anomaly.
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Affiliation(s)
- Sanghita Sengupta
- Département de physique, Institut quantique and Regroupement Québécois sur les Matériaux de Pointe, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - M Nabil Y Lhachemi
- Département de physique, Institut quantique and Regroupement Québécois sur les Matériaux de Pointe, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - Ion Garate
- Département de physique, Institut quantique and Regroupement Québécois sur les Matériaux de Pointe, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
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38
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Freitas GS, Piva MM, Grossi R, Jesus CBR, Souza JC, Christovam DS, Oliveira NF, Leão JB, Adriano C, Lynn JW, Pagliuso PG. Tuning the crystalline electric field and magnetic anisotropy along the CeCuBi2-xSbx series. PHYSICAL REVIEW. B 2020; 102:10.1103/PhysRevB.102.115129. [PMID: 37720400 PMCID: PMC10502689 DOI: 10.1103/physrevb.102.115129] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
We have performed X-ray powder diffraction, magnetization, electrical resistivity, heat capacity and inelastic neutron scattering (INS) to investigate the physical properties of the intermetallic series of compounds CeCuBi 2 - x Sb x . These compounds crystallize in a tetragonal structure with space group P 4 ∕ n m m and present antiferromagnetic transition temperatures ranging from 3.6 K to 16 K. Remarkably, the magnetization easy axis changed along the series, which is closely related to the variations of the tetragonal crystalline electric field (CEF) parameters. This evolution was analyzed using a mean field model, which included an anisotropic nearest-neighbor interactions and the tetragonal CEF Hamiltonian. We obtained the CEF parameters by fitting the magnetic susceptibility data with the constraints given by the INS measurements. More broadly, we discuss how this CEF evolution can affect the Kondo physics and the search for a superconducting state in this family.
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Affiliation(s)
- G. S. Freitas
- Instituto de Física “Gleb Wataghin”, UNICAMP, Campinas-SP, 13083-859, Brazil
| | - M. M. Piva
- Instituto de Física “Gleb Wataghin”, UNICAMP, Campinas-SP, 13083-859, Brazil
| | - R. Grossi
- Instituto de Física “Gleb Wataghin”, UNICAMP, Campinas-SP, 13083-859, Brazil
| | - C. B. R. Jesus
- Instituto de Física “Gleb Wataghin”, UNICAMP, Campinas-SP, 13083-859, Brazil
- Programa de Pós-Graduação em Física, Campus Prof. José Aluísio de Campos, UFS, 49100-000, São Cristóvão, SE, Brazil
| | - J. C. Souza
- Instituto de Física “Gleb Wataghin”, UNICAMP, Campinas-SP, 13083-859, Brazil
| | - D. S. Christovam
- Instituto de Física “Gleb Wataghin”, UNICAMP, Campinas-SP, 13083-859, Brazil
| | - N. F. Oliveira
- Instituto de Física, Universidade de São Paulo, São Paulo-SP, 05508-090, Brazil
| | - J. B. Leão
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6102
| | - C. Adriano
- Instituto de Física “Gleb Wataghin”, UNICAMP, Campinas-SP, 13083-859, Brazil
| | - J. W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6102
| | - P. G. Pagliuso
- Instituto de Física “Gleb Wataghin”, UNICAMP, Campinas-SP, 13083-859, Brazil
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