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Liu WY, Zhang XT, Wang Z, Gong SS, Chen WQ, Gu ZC. Quantum Criticality with Emergent Symmetry in the Extended Shastry-Sutherland Model. PHYSICAL REVIEW LETTERS 2024; 133:026502. [PMID: 39073958 DOI: 10.1103/physrevlett.133.026502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 02/19/2024] [Accepted: 05/29/2024] [Indexed: 07/31/2024]
Abstract
Motivated by the novel phenomena observed in the layered material SrCu_{2}(BO_{3})_{2}, the Shastry-Sutherland model (SSM) has been extensively studied as the minimal model for SrCu_{2}(BO_{3})_{2}. However, the nature of its quantum phase transition from the plaquette valence-bond solid to antiferromagnetic phase is under fierce debate, posing a challenge to understand the underlying quantum criticality. Via the state-of-the-art tensor network simulations, we study the ground state of the SSM on large-scale size up to 20×20 sites. We identify the continuous transition nature accompanied by an emergent O(4) symmetry between the plaquette valence-bond solid and antiferromagnetic phase, which strongly suggests a deconfined quantum critical point (DQCP). Furthermore, we map out the phase diagram of an extended SSM that can be continuously tuned to the SSM, which demonstrates the same DQCP phenomena along a whole critical line. Our results indicate a compelling scenario for understanding the origin of the proposed proximate DQCP in recent experiments of SrCu_{2}(BO_{3})_{2}.
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Affiliation(s)
| | | | | | - Shou-Shu Gong
- School of Physical Sciences, Great Bay University, Dongguan 523000, China, and Great Bay Institute for Advanced Study, Dongguan 523000, China
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2
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Fogh E, Nayak M, Prokhnenko O, Bartkowiak M, Munakata K, Soh JR, Turrini AA, Zayed ME, Pomjakushina E, Kageyama H, Nojiri H, Kakurai K, Normand B, Mila F, Rønnow HM. Field-induced bound-state condensation and spin-nematic phase in SrCu 2(BO 3) 2 revealed by neutron scattering up to 25.9 T. Nat Commun 2024; 15:442. [PMID: 38200029 PMCID: PMC10781965 DOI: 10.1038/s41467-023-44115-z] [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: 07/21/2023] [Accepted: 11/30/2023] [Indexed: 01/12/2024] Open
Abstract
In quantum magnetic materials, ordered phases induced by an applied magnetic field can be described as the Bose-Einstein condensation (BEC) of magnon excitations. In the strongly frustrated system SrCu2(BO3)2, no clear magnon BEC could be observed, pointing to an alternative mechanism, but the high fields required to probe this physics have remained a barrier to detailed investigation. Here we exploit the first purpose-built high-field neutron scattering facility to measure the spin excitations of SrCu2(BO3)2 up to 25.9 T and use cylinder matrix-product-states (MPS) calculations to reproduce the experimental spectra with high accuracy. Multiple unconventional features point to a condensation of S = 2 bound states into a spin-nematic phase, including the gradients of the one-magnon branches and the persistence of a one-magnon spin gap. This gap reflects a direct analogy with superconductivity, suggesting that the spin-nematic phase in SrCu2(BO3)2 is best understood as a condensate of bosonic Cooper pairs.
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Affiliation(s)
- Ellen Fogh
- Laboratory for Quantum Magnetism, Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland.
| | - Mithilesh Nayak
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland.
| | | | - Maciej Bartkowiak
- Helmholtz-Zentrum Berlin für Materialien und Energie, D-14109, Berlin, Germany
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell, OX11 0QX, UK
| | - Koji Munakata
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS), Tokai, Ibaraki, 319-1106, Japan
| | - Jian-Rui Soh
- Laboratory for Quantum Magnetism, Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Alexandra A Turrini
- Laboratory for Quantum Magnetism, Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232, Villigen-PSI, Switzerland
| | - Mohamed E Zayed
- Department of Physics, Carnegie Mellon University in Qatar, Education City, PO Box 24866, Doha, Qatar
| | - Ekaterina Pomjakushina
- Laboratory for Multiscale Materials Experiments, Paul Scherrer Institute, CH-5232, Villigen PSI, Switzerland
| | - Hiroshi Kageyama
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Hiroyuki Nojiri
- Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan
| | - Kazuhisa Kakurai
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS), Tokai, Ibaraki, 319-1106, Japan
| | - Bruce Normand
- Laboratory for Quantum Magnetism, Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
- Laboratory for Theoretical and Computational Physics, Paul Scherrer Institute, CH-5232, Villigen-PSI, Switzerland
| | - Frédéric Mila
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Henrik M Rønnow
- Laboratory for Quantum Magnetism, Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
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3
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Nomura T, Corboz P, Miyata A, Zherlitsyn S, Ishii Y, Kohama Y, Matsuda YH, Ikeda A, Zhong C, Kageyama H, Mila F. Unveiling new quantum phases in the Shastry-Sutherland compound SrCu 2(BO 3) 2 up to the saturation magnetic field. Nat Commun 2023; 14:3769. [PMID: 37355682 DOI: 10.1038/s41467-023-39502-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 06/13/2023] [Indexed: 06/26/2023] Open
Abstract
Under magnetic fields, quantum magnets often undergo exotic phase transitions with various kinds of order. The discovery of a sequence of fractional magnetization plateaus in the Shastry-Sutherland compound SrCu2(BO3)2 has played a central role in the high-field research on quantum materials, but so far this system could only be probed up to half the saturation value of the magnetization. Here, we report the first experimental and theoretical investigation of this compound up to the saturation magnetic field of 140 T and beyond. Using ultrasound and magnetostriction techniques combined with extensive tensor-network calculations (iPEPS), several spin-supersolid phases are revealed between the 1/2 plateau and saturation (1/1 plateau). Quite remarkably, the sound velocity of the 1/2 plateau exhibits a drastic decrease of -50%, related to the tetragonal-to-orthorhombic instability of the checkerboard-type magnon crystal. The unveiled nature of this paradigmatic quantum system is a new milestone for exploring exotic quantum states of matter emerging in extreme conditions.
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Affiliation(s)
- T Nomura
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba, Japan.
- Tokyo Denki University, Adachi, Tokyo, Japan.
| | - P Corboz
- Institute for Theoretical Physics and Delta Institute for Theoretical Physics, University of Amsterdam, XH, Amsterdam, The Netherlands.
| | - A Miyata
- Hochfeld-Magnetlabor Dresden (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - S Zherlitsyn
- Hochfeld-Magnetlabor Dresden (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Y Ishii
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba, Japan
| | - Y Kohama
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba, Japan
| | - Y H Matsuda
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba, Japan
| | - A Ikeda
- Department of Engineering Science, University of Electro-Communications, Chofu, Tokyo, Japan
| | - C Zhong
- Graduate School of Engineering, Kyoto University, Nishikyouku, Kyoto, Japan
- Department of Applied Chemistry, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - H Kageyama
- Graduate School of Engineering, Kyoto University, Nishikyouku, Kyoto, Japan
| | - F Mila
- Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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4
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Marshall M, Billingsley BR, Bai X, Ma Q, Kong T, Cao H. Field-induced partial disorder in a Shastry-Sutherland lattice. Nat Commun 2023; 14:3641. [PMID: 37336899 DOI: 10.1038/s41467-023-39409-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 06/13/2023] [Indexed: 06/21/2023] Open
Abstract
A 2-Q antiferromagnetic order of the ferromagnetic dimers was found below TN = 2.9 K in the Shastry-Sutherland lattice BaNd2ZnS5 by single crystal neutron diffraction. The magnetic order can be understood by the orthogonal arrangement of local Ising Nd spins, identified by polarized neutrons. A field was applied along [1 -1 0] to probe the observed metamagnetic transition in the magnetization measurement. The field decouples two magnetic sublattices corresponding to the propagation vectors q1 = (½, ½, 0) and q2 = (-½, ½, 0), respectively. Each sublattice shows a "stripe" order with a Néel-type arrangement in each single layer. The "stripe" order with q1 remains nearly intact up to 6 T, while the other one with q2 is suppressed at a critical field Hc ~1.7 T, indicating a partial disorder. The Hc varies with temperature and is manifested in the H-T phase diagram constructed by measuring the magnetization in BaNd2ZnS5.
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Affiliation(s)
- Madalynn Marshall
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | | | - Xiaojian Bai
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Department of Physics and Astronomy, University of Louisiana, Baton Rouge, LO, 70803, USA
| | - Qianli Ma
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Tai Kong
- Department of Physics, University of Arizona, Tucson, AZ, 85721, USA
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA
| | - Huibo Cao
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
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Imajo S, Matsuyama N, Nomura T, Kihara T, Nakamura S, Marcenat C, Klein T, Seyfarth G, Zhong C, Kageyama H, Kindo K, Momoi T, Kohama Y. Magnetically Hidden State on the Ground Floor of the Magnetic Devil's Staircase. PHYSICAL REVIEW LETTERS 2022; 129:147201. [PMID: 36240417 DOI: 10.1103/physrevlett.129.147201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/20/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
We investigated the low-temperature and high-field thermodynamic and ultrasonic properties of SrCu_{2}(BO_{3})_{2}, which exhibits various plateaux in its magnetization curve above 27 T, called a magnetic Devil's staircase. The results of the present study confirm that magnetic crystallization, the first step of the staircase, occurs above 27 T as a first-order transition accompanied by a sharp singularity in heat capacity C_{p} and a kink in the elastic constant. In addition, we observe a thermodynamic anomaly at lower fields around 26 T, which has not been previously detected by any magnetic probes. At low temperatures, this magnetically hidden state has a large entropy and does not exhibit Schottky-type gapped behavior, which suggests the existence of low-energy collective excitations. Based on our observations and theoretical predictions, we propose that magnetic quadrupoles form a spin-nematic state around 26 T as a hidden state on the ground floor of the magnetic Devil's staircase.
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Affiliation(s)
- S Imajo
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - N Matsuyama
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - T Nomura
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - T Kihara
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - S Nakamura
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - C Marcenat
- Université Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, 38000 Grenoble, France
| | - T Klein
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, F-38000 Grenoble, France
| | - G Seyfarth
- LNCMI-EMFL, CNRS, Université Grenoble Alpes, INSA-T, UPS, F-38042 Grenoble, France
| | - C Zhong
- Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - H Kageyama
- Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - K Kindo
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - T Momoi
- Condensed Matter Theory Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - Y Kohama
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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6
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Shi Z, Dissanayake S, Corboz P, Steinhardt W, Graf D, Silevitch DM, Dabkowska HA, Rosenbaum TF, Mila F, Haravifard S. Discovery of quantum phases in the Shastry-Sutherland compound SrCu 2(BO 3) 2 under extreme conditions of field and pressure. Nat Commun 2022; 13:2301. [PMID: 35484351 PMCID: PMC9050886 DOI: 10.1038/s41467-022-30036-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 04/07/2022] [Indexed: 11/22/2022] Open
Abstract
The 2-dimensional layered oxide material SrCu2(BO3)2, long studied as a realization of the Shastry-Sutherland spin topology, exhibits a range of intriguing physics as a function of both hydrostatic pressure and magnetic field, with a still debated intermediate plaquette phase appearing at approximately 20 kbar and a possible deconfined critical point at higher pressure. Here, we employ a tunnel diode oscillator (TDO) technique to probe the behavior in the combined extreme conditions of high pressure, high magnetic field, and low temperature. We reveal an extensive phase space consisting of multiple magnetic analogs of the elusive supersolid phase and a magnetization plateau. In particular, a 10 × 2 supersolid and a 1/5 plateau, identified by infinite Projected Entangled Pair States (iPEPS) calculations, are found to rely on the presence of both magnetic and non-magnetic particles in the sea of dimer singlets. These states are best understood as descendants of the full-plaquette phase, the leading candidate for the intermediate phase of SrCu2(BO3)2.
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Affiliation(s)
- Zhenzhong Shi
- Department of Physics, Duke University, Durham, NC, 27708, USA
- Institute for Advanced Study, School of Physical Science and Technology, Soochow University, Suzhou, 215006, China
| | | | - Philippe Corboz
- Institute for Theoretical Physics and Delta Institute for Theoretical Physics, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | | | - David Graf
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - D M Silevitch
- Division of Physics, Math and Astronomy, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Hanna A Dabkowska
- Brockhouse Institute for Material Research, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - T F Rosenbaum
- Division of Physics, Math and Astronomy, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Frédéric Mila
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Sara Haravifard
- Department of Physics, Duke University, Durham, NC, 27708, USA.
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, 27708, USA.
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7
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Kurita N, Yamamoto D, Kanesaka T, Furukawa N, Ohira-Kawamura S, Nakajima K, Tanaka H. Localized Magnetic Excitations in the Fully Frustrated Dimerized Magnet Ba_{2}CoSi_{2}O_{6}Cl_{2}. PHYSICAL REVIEW LETTERS 2019; 123:027206. [PMID: 31386547 DOI: 10.1103/physrevlett.123.027206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 04/08/2019] [Indexed: 06/10/2023]
Abstract
Magnetic excitations of the effective spin S=1/2 dimerized magnet Ba_{2}CoSi_{2}O_{6}Cl_{2} have been probed directly via inelastic neutron scattering experiments at temperatures down to 4 K. We observed five types of excitation at 4.8, 5.8, 6.6, 11.4, and 14.0 meV, which are all dispersionless within the resolution limits. The scattering intensities of the three low-lying excitations were found to exhibit different Q dependencies. Detailed analysis has demonstrated that Ba_{2}CoSi_{2}O_{6}Cl_{2} is a two-dimensional spin dimer system described only by a single dimer site, where the triplet excitations are localized owing to the almost perfect frustration of the interdimer exchange interactions and the undimerized spins, even in small concentration, make an essential contribution to the excitation spectrum.
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Affiliation(s)
- Nobuyuki Kurita
- Department of Physics, Tokyo Institute of Technology, Oh-okayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Daisuke Yamamoto
- Department of Physics and Mathematics, Aoyama-Gakuin University, Sagamihara, Kanagawa 252-5258, Japan
| | - Takuya Kanesaka
- Department of Physics and Mathematics, Aoyama-Gakuin University, Sagamihara, Kanagawa 252-5258, Japan
| | - Nobuo Furukawa
- Department of Physics and Mathematics, Aoyama-Gakuin University, Sagamihara, Kanagawa 252-5258, Japan
| | - Seiko Ohira-Kawamura
- Materials and Life Science Division, J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - Kenji Nakajima
- Materials and Life Science Division, J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - Hidekazu Tanaka
- Department of Physics, Tokyo Institute of Technology, Oh-okayama, Meguro-ku, Tokyo 152-8551, Japan
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8
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Shi Z, Steinhardt W, Graf D, Corboz P, Weickert F, Harrison N, Jaime M, Marjerrison C, Dabkowska HA, Mila F, Haravifard S. Emergent bound states and impurity pairs in chemically doped Shastry-Sutherland system. Nat Commun 2019; 10:2439. [PMID: 31164637 PMCID: PMC6547672 DOI: 10.1038/s41467-019-10410-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 05/09/2019] [Indexed: 11/17/2022] Open
Abstract
Impurities often play a defining role in the ground states of frustrated quantum magnets. Studies of their effects are crucial in understanding of the phase diagram in these materials. SrCu2(BO3)2, an experimental realization of the Shastry-Sutherland (SS) lattice, provides a unique model system for such studies using both experimental and numerical approaches. Here we report effects of impurities on the crystals of bound states, and doping-induced emergent ground states in Mg-doped SrCu2(BO3)2, which remain stable in high magnetic fields. Using four complementary magnetometry techniques and theoretical simulations, a rich impurity-induced phenomenology at high fields is discovered. The results demonstrate a rare example in which even a small doping concentration interacts strongly with both triplets and bound states of triplets, and thus plays a significant role in the magnetization process even at high magnetic fields. Our findings provide insights into the study of impurity effects in geometrically frustrated quantum magnets. Exploring the impurity-induced phenomena facilitates the understanding of emergent quantum materials. Here the authors show the anomalous magnetization transitions as well as demonstrate the relation between the impurities and the excited spin states in the Mg doped Shastry-Sutherland compound SrCu2(BO3)2.
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Affiliation(s)
- Zhenzhong Shi
- Department of Physics, Duke University, Durham, NC, 27708, USA
| | | | - David Graf
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Philippe Corboz
- Institute for Theoretical Physics and Delta Institute for Theoretical Physics, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Franziska Weickert
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Neil Harrison
- National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Marcelo Jaime
- National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | | | - Hanna A Dabkowska
- Brockhouse Institute for Material Research, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
| | - Frédéric Mila
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Sara Haravifard
- Department of Physics, Duke University, Durham, NC, 27708, USA. .,Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, 27708, USA.
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9
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Wang Z, Batista CD. Dynamics and Instabilities of the Shastry-Sutherland Model. PHYSICAL REVIEW LETTERS 2018; 120:247201. [PMID: 29956985 DOI: 10.1103/physrevlett.120.247201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Indexed: 06/08/2023]
Abstract
We study the excitation spectrum in the dimer phase of the Shastry-Sutherland model by using an unbiased variational method that works in the thermodynamic limit. The method outputs dynamical correlation functions in all possible channels. This output is exploited to identify the order parameters with the highest susceptibility (single or multitriplon condensation in a specific channel) upon approaching a quantum phase transition in the magnetic field versus the J^{'}/J phase diagram. We find four different instabilities: antiferro spin nematic, plaquette spin nematic, stripe magnetic order, and plaquette order, two of which have been reported in previous studies.
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Affiliation(s)
- Zhentao Wang
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Cristian D Batista
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA
- Quantum Condensed Matter Division and Shull-Wollan Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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10
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Tang Y, Chia CI, Crespi VH. Dual-Sided Adsorption: Devil's Staircase of Coverage Fractions. PHYSICAL REVIEW LETTERS 2018; 120:056101. [PMID: 29481191 DOI: 10.1103/physrevlett.120.056101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 10/18/2017] [Indexed: 06/08/2023]
Abstract
By adsorbing the same species onto both sides of a suspended, atomically thin membrane, it is possible to couple two distinct surface adsorption systems. This new system, with reflection symmetry about the membrane, is described by a phase diagram with two axes, both representing the chemical potential of the same element, but in distinct half-spaces. For the case of potassium adsorption onto a graphene membrane, the result is a devil's staircase of fractions for the proportion of adsorbates adhered to one side. Fractions with simpler denominators are favored across wider regions of chemical potential, a pattern reminiscent of other fractional systems across a wide range of physics. Since the system can support multiple devil's staircases each at a distinct overall adsorbate areal density, points along the boundary between adjacent staircases can come arbitrarily close to violating the Gibbs phase rule. This dual-sided adsorbate geometry provides a means to explore surface science for pairs of weakly coupled surfaces.
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Affiliation(s)
- Youjian Tang
- Department of Physics, The Pennsylvania State University, 104 Davey Lab, University Park, Pennsylvania 16802-6300, USA
| | - Cheng-Ing Chia
- Department of Physics, The Pennsylvania State University, 104 Davey Lab, University Park, Pennsylvania 16802-6300, USA
| | - Vincent H Crespi
- Department of Physics, The Pennsylvania State University, 104 Davey Lab, University Park, Pennsylvania 16802-6300, USA
- Department of Materials Science and Engineering, The Pennsylvania State University, 104 Davey Lab, University Park, Pennsylvania 16802-6300, USA
- Materials Research Institute, The Pennsylvania State University, 104 Davey Lab, University Park, Pennsylvania 16802-6300, USA
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11
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Kohlrautz J, Haase J, Green EL, Zhang ZT, Wosnitza J, Herrmannsdörfer T, Dabkowska HA, Gaulin BD, Stern R, Kühne H. Field-stepped broadband NMR in pulsed magnets and application to SrCu2(BO3)2 at 54T. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 271:52-59. [PMID: 27552555 DOI: 10.1016/j.jmr.2016.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/09/2016] [Accepted: 08/10/2016] [Indexed: 06/06/2023]
Abstract
Pulsed magnets generate the highest magnetic fields as brief transients during which the observation of NMR is difficult, however, this is the only route to unique insight into material properties up to the regime of 100T. Here, it is shown how rather broad NMR spectra can be assembled in a pulsed magnet during a single field pulse by using the inherent time dependence of the field for the recording of field-stepped free induction decays that cover a broad frequency range. The technique is then applied to (11)B NMR of the spin-dimer system SrCu2(BO3)2, a magnetic insulator known to undergo a series of field-driven changes of the magnetic ground state. At peak fields of about 54T at the Dresden High Magnetic Field Laboratory, (11)B NMR spectra spanning a total of about 9MHz width are reconstructed. The results are in good accordance with a change from a high-temperature paramagnetic state to a low-temperature commensurate superstructure of field-induced spin-dimer triplets.
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Affiliation(s)
- J Kohlrautz
- University of Leipzig, Faculty of Physics and Earth Sciences, Linnéstraße 5, 04103 Leipzig, Germany.
| | - J Haase
- University of Leipzig, Faculty of Physics and Earth Sciences, Linnéstraße 5, 04103 Leipzig, Germany
| | - E L Green
- Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
| | - Z T Zhang
- Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
| | - J Wosnitza
- Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany; Institut für Festkörperphysik, TU Dresden, 01062 Dresden, Germany
| | - T Herrmannsdörfer
- Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
| | - H A Dabkowska
- Brockhouse Institute for Materials Research and Department of Physics and Astronomy, McMaster University, 1280 Main Str West, ON L8S 4M1, Canada
| | - B D Gaulin
- Brockhouse Institute for Materials Research and Department of Physics and Astronomy, McMaster University, 1280 Main Str West, ON L8S 4M1, Canada
| | - R Stern
- National Institute of Chemical Physics and Biophysics (NICPB), Akadeemia Tee 23, 12618 Tallinn, Estonia
| | - H Kühne
- Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
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12
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Yoshida M, Kobayashi H, Yamauchi I, Takigawa M, Capponi S, Poilblanc D, Mila F, Kudo K, Koike Y, Kobayashi N. Real space imaging of spin polarons in Zn-doped SrCu(2)(BO(3))(2). PHYSICAL REVIEW LETTERS 2015; 114:056402. [PMID: 25699459 DOI: 10.1103/physrevlett.114.056402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Indexed: 06/04/2023]
Abstract
We report on the real space profile of spin polarons in the quasi-two-dimensional frustrated dimer spin system SrCu(2)(BO(3))(2) doped with 0.16% of Zn. The (11)B nuclear magnetic resonance spectrum exhibits 15 additional boron sites near nonmagnetic Zn impurities. With the help of exact diagonalizations of finite clusters, we have deduced from the boron spectrum, the distribution of local magnetizations at the Cu sites with fine spatial resolution, providing direct evidence for an extended spin polaron. The results are confronted with those of other experiments performed on doped and undoped samples of SrCu(2)(BO(3))(2).
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Affiliation(s)
- M Yoshida
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - H Kobayashi
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - I Yamauchi
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - M Takigawa
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - S Capponi
- Laboratoire de Physique Théorique, Université de Toulouse and CNRS, UPS (IRSAMC), F-31062 Toulouse, France
| | - D Poilblanc
- Laboratoire de Physique Théorique, Université de Toulouse and CNRS, UPS (IRSAMC), F-31062 Toulouse, France
| | - F Mila
- Institut de Théorie des Phénomènes Physiques, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - K Kudo
- Department of Physics, Okayama University, Okayama 700-8530, Japan
| | - Y Koike
- Department of Applied Physics, Tohoku University, Sendai 980-8579, Japan
| | - N Kobayashi
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
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13
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Shukrinov YM, Botha AE, Medvedeva SY, Kolahchi MR, Irie A. Structured chaos in a devil's staircase of the Josephson junction. CHAOS (WOODBURY, N.Y.) 2014; 24:033115. [PMID: 25273195 DOI: 10.1063/1.4890573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The phase dynamics of Josephson junctions (JJs) under external electromagnetic radiation is studied through numerical simulations. Current-voltage characteristics, Lyapunov exponents, and Poincaré sections are analyzed in detail. It is found that the subharmonic Shapiro steps at certain parameters are separated by structured chaotic windows. By performing a linear regression on the linear part of the data, a fractal dimension of D = 0.868 is obtained, with an uncertainty of ±0.012. The chaotic regions exhibit scaling similarity, and it is shown that the devil's staircase of the system can form a backbone that unifies and explains the highly correlated and structured chaotic behavior. These features suggest a system possessing multiple complete devil's staircases. The onset of chaos for subharmonic steps occurs through the Feigenbaum period doubling scenario. Universality in the sequence of periodic windows is also demonstrated. Finally, the influence of the radiation and JJ parameters on the structured chaos is investigated, and it is concluded that the structured chaos is a stable formation over a wide range of parameter values.
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Affiliation(s)
| | - A E Botha
- Department of Physics, University of South Africa, Science Campus, Private Bag X6, Florida Park 1710, South Africa
| | | | - M R Kolahchi
- Institute for Advanced Studies in Basic Sciences, P.O. Box 45195-1159, Zanjan, Iran
| | - A Irie
- Department of Electrical and Electronic Systems Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya 321-8585, Japan
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14
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Liu HD, Chen YH, Lin HF, Tao HS, Liu WM. Antiferromagnetic metal and Mott transition on Shastry-Sutherland lattice. Sci Rep 2014; 4:4829. [PMID: 24777282 PMCID: PMC4003478 DOI: 10.1038/srep04829] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 04/09/2014] [Indexed: 11/08/2022] Open
Abstract
The Shastry-Sutherland lattice, one of the simplest systems with geometrical frustration, which has an exact eigenstate by putting singlets on diagonal bonds, can be realized in a group of layered compounds and raises both theoretical and experimental interest. Most of the previous studies on the Shastry-Sutherland lattice are focusing on the Heisenberg model. Here we opt for the Hubbard model to calculate phase diagrams over a wide range of interaction parameters, and show the competing effects of interaction, frustration and temperature. At low temperature, frustration is shown to favor a paramagnetic metallic ground state, while interaction drives the system to an antiferromagnetic insulator phase. Between these two phases, there are an antiferromagnetic metal phase and a paramagnetic insulator phase (which should consist of a small plaquette phase and a dimer phase) resulting from the competition of the frustration and the interaction. Our results may shed light on more exhaustive studies about quantum phase transitions in geometrically frustrated systems.
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Affiliation(s)
- Hai-Di Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yao-Hua Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Heng-Fu Lin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hong-Shuai Tao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Wu-Ming Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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15
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Corboz P, Mila F. Crystals of bound states in the magnetization plateaus of the Shastry-Sutherland model. PHYSICAL REVIEW LETTERS 2014; 112:147203. [PMID: 24766008 DOI: 10.1103/physrevlett.112.147203] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Indexed: 06/03/2023]
Abstract
Using infinite projected entangled-pair states, we show that the Shastry-Sutherland model in an external magnetic field has low-magnetization plateaus which, in contrast to previous predictions, correspond to crystals of bound states of triplets, and not to crystals of triplets. The first sizable plateaus appear at magnetization 1/8, 2/15 and 1/6, in agreement with experiments on the orthogonal-dimer antiferromagnet SrCu2(BO3)2, and they can be naturally understood as regular patterns of bound states, including the intriguing 2/15 one. We also show that, even in a confined geometry, two triplets bind into a localized bound state with Sz=2. Finally, we discuss the role of competing domain-wall and supersolid phases, as well as that of additional anisotropic interactions.
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Affiliation(s)
- Philippe Corboz
- Theoretische Physik, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Frédéric Mila
- Institut de Théorie des Phénomènes Physiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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16
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Matsuda YH, Abe N, Takeyama S, Kageyama H, Corboz P, Honecker A, Manmana SR, Foltin GR, Schmidt KP, Mila F. Magnetization of SrCu2(BO3)2 in ultrahigh magnetic fields up to 118 T. PHYSICAL REVIEW LETTERS 2013; 111:137204. [PMID: 24116813 DOI: 10.1103/physrevlett.111.137204] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Indexed: 06/02/2023]
Abstract
The magnetization process of the orthogonal-dimer antiferromagnet SrCu2(BO3)2 is investigated in high magnetic fields of up to 118 T. A 1/2 plateau is clearly observed in the field range 84 to 108 T in addition to 1/8, 1/4, and 1/3 plateaus at lower fields. Using a combination of state-of-the-art numerical simulations, the main features of the high-field magnetization, a 1/2 plateau of width 24 T, a 1/3 plateau of width 34 T, and no 2/5 plateau, are shown to agree quantitatively with the Shastry-Sutherland model if the ratio of inter- to intradimer exchange interactions J'/J=0.63. It is further predicted that the intermediate phase between the 1/3 and 1/2 plateaus is not uniform but consists of a 1/3 supersolid followed by a 2/5 supersolid and possibly a domain-wall phase, with a reentrance into the 1/3 supersolid above the 1/2 plateau.
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Affiliation(s)
- Y H Matsuda
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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