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Gitgeatpong G, Zhao Y, Piyawongwatthana P, Qiu Y, Harriger LW, Butch NP, Sato TJ, Matan K. Nonreciprocal Magnons and Symmetry-Breaking in the Noncentrosymmetric Antiferromagnet. PHYSICAL REVIEW LETTERS 2017; 119:047201. [PMID: 29341758 DOI: 10.1103/physrevlett.119.047201] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Indexed: 06/07/2023]
Abstract
Inelastic neutron scattering measurements were performed to study spin dynamics in the noncentrosymmetric antiferromagnet α-Cu_{2}V_{2}O_{7}. For the first time, nonreciprocal magnons were experimentally measured in an antiferromagnet. These nonreciprocal magnons are caused by the incompatibility between anisotropic exchange and antisymmetric Dzyaloshinskii-Moriya interactions, which arise from broken symmetry, resulting in a collinear ordered state but helical spin dynamics. The nonreciprocity introduces the difference in the phase velocity of the counterrotating modes, causing the opposite spontaneous magnonic Faraday rotation of the left- and right-propagating spin waves. The breaking of spatial inversion and time reversal symmetry is revealed as a magnetic-field-induced asymmetric energy shift, which provides a test for the detailed balance relation.
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Affiliation(s)
- G Gitgeatpong
- Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- ThEP, Commission of Higher Education, Bangkok 10400, Thailand
- Department of Physics, Faculty of Science and Technology, Phranakhon Rajabhat University, Bangkok 10220, Thailand
| | - Y Zhao
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - P Piyawongwatthana
- Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Y Qiu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - L W Harriger
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - N P Butch
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - T J Sato
- IMRAM, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - K Matan
- Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- ThEP, Commission of Higher Education, Bangkok 10400, Thailand
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Fujiyama S, Ohsumi H, Komesu T, Matsuno J, Kim BJ, Takata M, Arima T, Takagi H. Two-dimensional Heisenberg behavior of J(eff)=1/2 isospins in the paramagnetic state of the spin-orbital Mott insulator Sr2IrO4. PHYSICAL REVIEW LETTERS 2012; 108:247212. [PMID: 23004324 DOI: 10.1103/physrevlett.108.247212] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Indexed: 06/01/2023]
Abstract
The dynamical correlations of J(eff)=1/2 isospins in the paramagnetic state of spin-orbital Mott insulator Sr2IrO4 were revealed by resonant magnetic x-ray diffuse scattering. We found a two-dimensional antiferromagnetic fluctuation with a large in-plane correlation length exceeding 100 lattice spacings at even 20 K above the magnetic ordering temperature. In marked contrast to the naive expectation of the strong magnetic anisotropy associated with an enhanced spin-orbit coupling, we discovered an isotropic isospin correlation that is well described by the two-dimensional S=1/2 quantum Heisenberg model. The estimated antiferromagnetic coupling constant as large as J∼0.1 eV that is comparable to the small Mott gap (<0.5 eV) points out the weak and marginal Mott character of this spin-orbital entangled system.
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Affiliation(s)
- S Fujiyama
- RIKEN Advanced Science Institute, Wako 351-0198, Japan.
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Lavrov AN, Ando Y, Komiya S, Tsukada I. Unusual magnetic susceptibility anisotropy in untwinned La2-xSr(x)CuO4 single crystals in the lightly doped region. PHYSICAL REVIEW LETTERS 2001; 87:017007. [PMID: 11461491 DOI: 10.1103/physrevlett.87.017007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2001] [Indexed: 05/23/2023]
Abstract
We present a study of the magnetic susceptibility chi in carefully detwinned La 2-xSr(x)CuO4 single crystals in the lightly doped region (x = 0-0.03), which demonstrates a remarkable in-plane anisotropy of the spin system. This anisotropy, chi(a)/chi(b), is found to persist after the long-range antiferromagnetic (AF) order is destroyed by hole doping, suggesting that doped holes break the AF order into domains in which the spin alignment is kept essentially intact. It turns out that the freezing of the spins taking place at low temperatures is also notably anisotropic, implying that the "spin-glass" feature is governed by the domain structure as well.
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Affiliation(s)
- A N Lavrov
- Central Research Institute of Electric Power Industry, 2-11-1 Iwato-kita, Komae, Tokyo 201-8511 Japan
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Chou FC, Johnston DC. Phase separation and oxygen diffusion in electrochemically oxidized La2CuO4+ delta : A static magnetic susceptibility study. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:572-583. [PMID: 9984293 DOI: 10.1103/physrevb.54.572] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Neutron scattering study of the two-dimensional spinS=1/2 square-lattice Heisenberg antiferromagnet Sr2CuO2Cl2. ACTA ACUST UNITED AC 1995. [DOI: 10.1007/bf01313844] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Spin dynamics and spin correlations in the spinS=1 two-dimensional square-lattice Heisenberg antiferromagnet La2NiO4. ACTA ACUST UNITED AC 1995. [DOI: 10.1007/bf01313845] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Suh BJ, Borsa F, Miller LL, Corti M, Johnston DC, Torgeson DR. Spin correlations and magnetic field effects in the weakly anisotropic square-lattice antiferromagnet Sr2CuO2Cl2. PHYSICAL REVIEW LETTERS 1995; 75:2212-2215. [PMID: 10059242 DOI: 10.1103/physrevlett.75.2212] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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