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Krempaský J, Springholz G, D'Souza SW, Caha O, Gmitra M, Ney A, Vaz CAF, Piamonteze C, Fanciulli M, Kriegner D, Krieger JA, Prokscha T, Salman Z, Minár J, Dil JH. Efficient magnetic switching in a correlated spin glass. Nat Commun 2023; 14:6127. [PMID: 37779120 PMCID: PMC10543544 DOI: 10.1038/s41467-023-41718-4] [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: 03/25/2023] [Accepted: 09/15/2023] [Indexed: 10/03/2023] Open
Abstract
The interplay between spin-orbit interaction and magnetic order is one of the most active research fields in condensed matter physics and drives the search for materials with novel, and tunable, magnetic and spin properties. Here we report on a variety of unique and unexpected observations in thin multiferroic Ge1-xMnxTe films. The ferrimagnetic order parameter in this ferroelectric semiconductor is found to switch direction under magnetostochastic resonance with current pulses many orders of magnitude lower as for typical spin-orbit torque systems. Upon a switching event, the magnetic order spreads coherently and collectively over macroscopic distances through a correlated spin-glass state. Utilizing these observations, we apply a novel methodology to controllably harness this stochastic magnetization dynamics.
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Affiliation(s)
- Juraj Krempaský
- Photon Science Division, Paul Scherrer Institut, CH-5232, Villigen, Switzerland.
| | - Gunther Springholz
- Institut für Halbleiter-und Festkörperphysik, Johannes Kepler Universität, A-4040, Linz, Austria
| | | | - Ondřej Caha
- Dept. of Condensed Matter Physics, Masaryk University, Kotlářská 267/2, 61137, Brno, Czech Republic
| | - Martin Gmitra
- Institute of Physics, P. J. Šafárik University in Košice, Park Angelinum 9, 040 01, Košice, Slovakia
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01, Košice, Slovakia
| | - Andreas Ney
- Institut für Halbleiter-und Festkörperphysik, Johannes Kepler Universität, A-4040, Linz, Austria
| | - C A F Vaz
- Photon Science Division, Paul Scherrer Institut, CH-5232, Villigen, Switzerland
| | - Cinthia Piamonteze
- Photon Science Division, Paul Scherrer Institut, CH-5232, Villigen, Switzerland
| | - Mauro Fanciulli
- LPMS, CY Cergy Paris Université, 95031, Cergy-Pontoise, France
| | - Dominik Kriegner
- Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53, Praha 6, Czech Republic
- Dept. of Condensed Matter Physics, Charles University, Ke Karlovu 5, 121 16, Praha 2, Czech Republic
| | - Jonas A Krieger
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232, Villigen PSI, Switzerland
- Max Planck Institut für Mikrostrukturphysik, Weinberg 2, 06120, Halle, Germany
| | - Thomas Prokscha
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232, Villigen PSI, Switzerland
| | - Zaher Salman
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232, Villigen PSI, Switzerland
| | - Jan Minár
- New Technologies-Research Center University of West Bohemia, Plzeň, Czech Republic.
| | - J Hugo Dil
- Photon Science Division, Paul Scherrer Institut, CH-5232, Villigen, Switzerland.
- Institut de Physique, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.
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Abstract
SignificanceThere is an intense ongoing search for two-level quantum systems with long lifetimes for applications in quantum communication and computation. Much research has been focused on studying isolated spins in semiconductors or band insulators. Mott insulators provide an interesting alternative platform but have been far less explored. In this work we use a technique capable of resolving individual spins at atomic length scales, to measure the two-level switching of spin states in 1T-TaS2. We find quasi-1D chains of spin-1/2 electrons embedded in 1T-TaS2 which have exceptionally long lifetimes. The discovery of long-lived spin states in a tractable van der Waal material opens doors to using Mott systems in future quantum information applications.
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Mier C, Verlhac B, Garnier L, Robles R, Limot L, Lorente N, Choi DJ. Superconducting Scanning Tunneling Microscope Tip to Reveal Sub-millielectronvolt Magnetic Energy Variations on Surfaces. J Phys Chem Lett 2021; 12:2983-2989. [PMID: 33730501 DOI: 10.1021/acs.jpclett.1c00328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Combining the complex ordering ability of molecules with their local magnetic properties is a little-explored technique to tailor spin structures on surfaces. However, revealing the molecular geometry can be demanding. Nickelocene (Nc) molecules present a large spin-flip excitation leading to clear changes of conductance at the excitation-threshold bias. Using a superconducting tip, we have the energy resolution to detect small shifts of the Nc spin-flip excitation thresholds, permitting us to reveal the different individual environments of Nc molecules in an ordered layer. This knowledge allows us to reveal the adsorption configuration of a complex molecular structure formed by Nc molecules in different orientations and positions. As a consequence, we infer that Nc layers present a strong noncollinear magnetic-moment arrangement.
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Affiliation(s)
- Cristina Mier
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 Donostia-San Sebastián, Spain
| | - Benjamin Verlhac
- Université de Strasbourg CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Léo Garnier
- Université de Strasbourg CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Roberto Robles
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 Donostia-San Sebastián, Spain
| | - Laurent Limot
- Université de Strasbourg CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Nicolás Lorente
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 Donostia-San Sebastián, Spain
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
| | - Deung-Jang Choi
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 Donostia-San Sebastián, Spain
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
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Kim H, Rózsa L, Schreyer D, Simon E, Wiesendanger R. Long-range focusing of magnetic bound states in superconducting lanthanum. Nat Commun 2020; 11:4573. [PMID: 32917904 PMCID: PMC7486372 DOI: 10.1038/s41467-020-18406-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 08/21/2020] [Indexed: 11/08/2022] Open
Abstract
Quantum mechanical systems with long-range interactions between quasiparticles provide a promising platform for coherent quantum information technology. Superconductors are a natural choice for solid-state based quantum devices, while magnetic impurities inside superconductors give rise to quasiparticle excitations of broken Cooper pairs that provide characteristic information about the host superconductor. Here, we reveal that magnetic impurities embedded below a superconducting La(0001) surface interact via quasiparticles extending to very large distances, up to several tens of nanometers. Using low-temperature scanning probe techniques, we observe the corresponding anisotropic and giant oscillations in the LDOS. Theoretical calculations indicate that the quasi-two-dimensional surface states with their strongly anisotropic Fermi surface play a crucial role for the focusing and long-range extension of the magnetic bound states. The quasiparticle focusing mechanism should facilitate the design of versatile magnetic structures with tunable and directed magnetic interactions over large distances, thereby paving the way toward the design of low-dimensional magnet-superconductor hybrid systems exhibiting topologically non-trivial quantum states as possible elements of quantum computation schemes based on Majorana quasiparticles.
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Affiliation(s)
- Howon Kim
- Department of Physics, University of Hamburg, D-20355, Hamburg, Germany.
| | - Levente Rózsa
- Department of Physics, University of Hamburg, D-20355, Hamburg, Germany
- Department of Physics, University of Konstanz, D-78457, Konstanz, Germany
| | - Dominik Schreyer
- Department of Physics, University of Hamburg, D-20355, Hamburg, Germany
| | - Eszter Simon
- Department of Theoretical Physics, Budapest University of Technology and Economics, Budafoki út 8, H-1111, Budapest, Hungary
- Department Chemie, Physikalische Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, D-81377, München, Germany
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Spethmann J, Meyer S, von Bergmann K, Wiesendanger R, Heinze S, Kubetzka A. Discovery of Magnetic Single- and Triple-q States in Mn/Re(0001). PHYSICAL REVIEW LETTERS 2020; 124:227203. [PMID: 32567896 DOI: 10.1103/physrevlett.124.227203] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/13/2020] [Indexed: 06/11/2023]
Abstract
We experimentally verify the existence of two model-type magnetic ground states that were previously predicted but so far unobserved. We find them in Mn monolayers on the Re(0001) surface using spin-polarized scanning tunneling microscopy. For fcc stacking of Mn the collinear row-wise antiferromagnetic state occurs, whereas for hcp Mn a three-dimensional spin structure appears, which is a superposition of three row-wise antiferromagnetic states known as the triple-q state. Density-functional theory calculations elucidate the subtle interplay of different magnetic interactions to form these spin structures and provide insight into the role played by relativistic effects.
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Affiliation(s)
- Jonas Spethmann
- Department of Physics, University of Hamburg, 20355 Hamburg, Germany
| | - Sebastian Meyer
- Institute of Theoretical Physics and Astrophysics, University of Kiel, Leibnizstrasse 15, 24098 Kiel, Germany
| | | | | | - Stefan Heinze
- Institute of Theoretical Physics and Astrophysics, University of Kiel, Leibnizstrasse 15, 24098 Kiel, Germany
| | - André Kubetzka
- Department of Physics, University of Hamburg, 20355 Hamburg, Germany
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