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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] [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. SrCu2(BO3)2 is a 2D quantum antiferromagnet on a particular frustrated lattice showing multiple magnetization plateaus and quantum phase transitions under high pressure. Here the authors uncover novel magnetic phases in this material under combined effects of extreme magnetic field and pressure.
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Huang HX, Chen J, Ren W, Gao Y, Li W, Chen Y. Insulator-metal transition and quasi-flat-band of Shastry-Sutherland lattice. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:345402. [PMID: 31096201 DOI: 10.1088/1361-648x/ab2228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Insulator-metal transition is investigated self-consistently on the frustrated Shastry-Sutherland lattice in the framework of Slave-Boson mean-field theory. Due to the presence of quasi-flat band structure characteristic, the system displays a spin-density-wave (SDW) insulating phase at the weak doping levels, which is robust against frustration, and it will be transited into an SDW metallic phase at high doping levels. As further increasing the doping, the temperature or the frustration on the diagonal linking bonds, the magnetic order m will be monotonically suppressed, resulting in the appearance of a paramagnetic metallic phase. Although the Fermi surface of the SDW metallic phase may be immersed by temperature, the number of mobile charges is robust against temperature at weak doping levels.
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Affiliation(s)
- Huai-Xiang Huang
- Department of Physics and Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, People's Republic of China
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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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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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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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Zayed ME, Rüegg C, Strässle T, Stuhr U, Roessli B, Ay M, Mesot J, Link P, Pomjakushina E, Stingaciu M, Conder K, Rønnow HM. Correlated decay of triplet excitations in the Shastry-Sutherland compound SrCu2(BO3)2. PHYSICAL REVIEW LETTERS 2014; 113:067201. [PMID: 25148346 DOI: 10.1103/physrevlett.113.067201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Indexed: 06/03/2023]
Abstract
The temperature dependence of the gapped triplet excitations (triplons) in the 2D Shastry-Sutherland quantum magnet SrCu(2)(BO(3))(2) is studied by means of inelastic neutron scattering. The excitation amplitude rapidly decreases as a function of temperature, while the integrated spectral weight can be explained by an isolated dimer model up to 10 K. Analyzing this anomalous spectral line shape in terms of damped harmonic oscillators shows that the observed damping is due to a two-component process: one component remains sharp and resolution limited while the second broadens. We explain the underlying mechanism through a simple yet quantitatively accurate model of correlated decay of triplons: an excited triplon is long lived if no thermally populated triplons are nearby but decays quickly if there are. The phenomenon is a direct consequence of frustration induced triplon localization in the Shastry-Sutherland lattice.
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Affiliation(s)
- M E Zayed
- Department of Mathematics, Statistics and Physics, College of Arts and Science, Qatar University, P.O. Box 2713, Doha, Qatar and Laboratory for Quantum Magnetism, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland and Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Ch Rüegg
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland and DPMC-MaNEP, University of Geneva, CH-1211 Geneva, Switzerland and London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
| | - Th Strässle
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - U Stuhr
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - B Roessli
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - M Ay
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - J Mesot
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland and Laboratory for Neutron and Synchrotron Spectroscopy, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland and Laboratory for Solid State Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - P Link
- Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM-2), D-85747 Garching, Germany
| | - E Pomjakushina
- Laboratory for Developments and Methods, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - M Stingaciu
- Laboratory for Developments and Methods, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - K Conder
- Laboratory for Developments and Methods, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - H M Rønnow
- Laboratory for Quantum Magnetism, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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Vojta M. Excitation spectra of disordered dimer magnets near quantum criticality. PHYSICAL REVIEW LETTERS 2013; 111:097202. [PMID: 24033066 DOI: 10.1103/physrevlett.111.097202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 08/16/2013] [Indexed: 06/02/2023]
Abstract
For coupled-dimer magnets with quenched disorder, we introduce a generalization of the bond-operator method, appropriate to describe both singlet and magnetically ordered phases. This allows for a numerical calculation of the magnetic excitations at all energies across the phase diagram, including the strongly inhomogeneous Griffiths regime near quantum criticality. We apply the method to the bilayer Heisenberg model with bond randomness and characterize both the broadening of excitations and the transfer of spectral weight induced by disorder. Inside the antiferromagnetic phase this model features the remarkable combination of sharp magnetic Bragg peaks and broad magnons, the latter arising from the tendency to localization of low-energy excitations.
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Affiliation(s)
- Matthias Vojta
- Institut für Theoretische Physik, Technische Universität Dresden, 01062 Dresden, Germany
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Haravifard S, Banerjee A, Lang JC, Srajer G, Silevitch DM, Gaulin BD, Dabkowska HA, Rosenbaum TF. Continuous and discontinuous quantum phase transitions in a model two-dimensional magnet. Proc Natl Acad Sci U S A 2012; 109:2286-9. [PMID: 22308373 PMCID: PMC3289308 DOI: 10.1073/pnas.1114464109] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Shasty-Sutherland model, which consists of a set of spin 1/2 dimers on a 2D square lattice, is simple and soluble but captures a central theme of condensed matter physics by sitting precariously on the quantum edge between isolated, gapped excitations and collective, ordered ground states. We compress the model Shastry-Sutherland material, SrCu(2)(BO(3))(2), in a diamond anvil cell at cryogenic temperatures to continuously tune the coupling energies and induce changes in state. High-resolution X-ray measurements exploit what emerges as a remarkably strong spin-lattice coupling to both monitor the magnetic behavior and the absence or presence of structural discontinuities. In the low-pressure spin-singlet regime, the onset of magnetism results in an expansion of the lattice with decreasing temperature, which permits a determination of the pressure-dependent energy gap and the almost isotropic spin-lattice coupling energies. The singlet-triplet gap energy is suppressed continuously with increasing pressure, vanishing completely by 2 GPa. This continuous quantum phase transition is followed by a structural distortion at higher pressure.
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Affiliation(s)
- S. Haravifard
- Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439
- James Franck Institute and Department of Physics, University of Chicago, 929 E 57th Street, Chicago, IL 60637
| | - A. Banerjee
- James Franck Institute and Department of Physics, University of Chicago, 929 E 57th Street, Chicago, IL 60637
| | - J. C. Lang
- Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439
| | - G. Srajer
- Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439
| | - D. M. Silevitch
- James Franck Institute and Department of Physics, University of Chicago, 929 E 57th Street, Chicago, IL 60637
| | - B. D. Gaulin
- Department of Physics and Astronomy, McMaster University, 1280 Main Street W, Hamilton, Ontario, L8S 4M1, Canada
- Canadian Institute for Advanced Research, 180 Dundas Street W, Toronto, Ontario, M5G 1Z8, Canada; and
- Brockhouse Institute for Material Research, McMaster University, 1280 Main Street W, Hamilton, Ontario, L8S 4M1, Canada
| | - H. A. Dabkowska
- Canadian Institute for Advanced Research, 180 Dundas Street W, Toronto, Ontario, M5G 1Z8, Canada; and
| | - T. F. Rosenbaum
- James Franck Institute and Department of Physics, University of Chicago, 929 E 57th Street, Chicago, IL 60637
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Stone MB, Podlesnyak A, Ehlers G, Huq A, Samulon EC, Shapiro MC, Fisher IR. Persistence of magnons in a site-diluted dimerized frustrated antiferromagnet. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:416003. [PMID: 21952109 DOI: 10.1088/0953-8984/23/41/416003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present inelastic neutron scattering and thermodynamic measurements characterizing the magnetic excitations in a disordered spin-liquid antiferromagnet with non-magnetic substitution. The parent compound Ba(3)Mn(2)O(8) is a dimerized, quasi-two-dimensional geometrically frustrated quantum disordered antiferromagnet. We substitute this compound with non-magnetic V(5+) for the S=1 Mn(5+) ions, Ba(3)(Mn(1-x)V (x))(2)O(8), and find that the singlet-triplet excitations which dominate the spectrum of the parent compound persist for the full range of substitution examined, up to x=0.3. We also observe additional low-energy magnetic fluctuations which are enhanced at the greatest substitution values.
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Affiliation(s)
- M B Stone
- Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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Vecchini C, Adamopoulos O, Chapon L, Lappas A, Kageyama H, Ueda Y, Zorko A. Structural distortions in the spin-gap regime of the quantum antiferromagnet SrCu2(BO3)2. J SOLID STATE CHEM 2009. [DOI: 10.1016/j.jssc.2009.09.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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