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Flavián D, Volkov PA, Hayashida S, Povarov KY, Gvasaliya S, Chandra P, Zheludev A. Dielectric Relaxation by Quantum Critical Magnons. PHYSICAL REVIEW LETTERS 2023; 130:216501. [PMID: 37295092 DOI: 10.1103/physrevlett.130.216501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/02/2023] [Accepted: 05/01/2023] [Indexed: 06/12/2023]
Abstract
We report the experimental observation of dielectric relaxation by quantum critical magnons. Complex capacitance measurements reveal a dissipative feature with a temperature-dependent amplitude due to low-energy lattice excitations and an activation behavior of the relaxation time. The activation energy softens close to a field-tuned magnetic quantum critical point at H=H_{c} and follows single-magnon energy for H>H_{c}, showing its magnetic origin. Our study demonstrates the electrical activity of coupled low-energy spin and lattice excitations, an example of quantum multiferroic behavior.
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Affiliation(s)
- Daniel Flavián
- Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich, Switzerland
| | - Pavel A Volkov
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
- Department of Physics and Astronomy, Center for Materials Theory, Rutgers University, Piscataway, New Jersey 08854, USA
| | - S Hayashida
- Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich, Switzerland
| | - K Yu Povarov
- Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich, Switzerland
| | - S Gvasaliya
- Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich, Switzerland
| | - Premala Chandra
- Department of Physics and Astronomy, Center for Materials Theory, Rutgers University, Piscataway, New Jersey 08854, USA
| | - A Zheludev
- Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich, Switzerland
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Watanabe Y, Miyake A, Gen M, Mizukami Y, Hashimoto K, Shibauchi T, Ikeda A, Tokunaga M, Kurumaji T, Tokunaga Y, Arima TH. Double dome structure of the Bose-Einstein condensation in diluted S = 3/2 quantum magnets. Nat Commun 2023; 14:1260. [PMID: 36898999 PMCID: PMC10006222 DOI: 10.1038/s41467-023-36725-4] [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: 04/24/2022] [Accepted: 02/14/2023] [Indexed: 03/12/2023] Open
Abstract
Bose-Einstein condensation (BEC) in quantum magnets, where bosonic spin excitations condense into ordered ground states, is a realization of BEC in a thermodynamic limit. Although previous magnetic BEC studies have focused on magnets with small spins of S ≤ 1, larger spin systems potentially possess richer physics because of the multiple excitations on a single site level. Here, we show the evolution of the magnetic phase diagram of S = 3/2 quantum magnet Ba2CoGe2O7 when the averaged interaction J is controlled by a dilution of magnetic sites. By partial substitution of Co with nonmagnetic Zn, the magnetic order dome transforms into a double dome structure, which can be explained by three kinds of magnetic BECs with distinct excitations. Furthermore, we show the importance of the randomness effects induced by the quenched disorder: we discuss the relevance of geometrical percolation and Bose/Mott glass physics near the BEC quantum critical point.
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Affiliation(s)
- Yoshito Watanabe
- Department of Advanced Materials Science, The University of Tokyo, Kashiwa, 277-8561, Japan.
| | - Atsushi Miyake
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, 277-8581, Japan
| | - Masaki Gen
- Department of Advanced Materials Science, The University of Tokyo, Kashiwa, 277-8561, Japan
| | - Yuta Mizukami
- Department of Advanced Materials Science, The University of Tokyo, Kashiwa, 277-8561, Japan
| | - Kenichiro Hashimoto
- Department of Advanced Materials Science, The University of Tokyo, Kashiwa, 277-8561, Japan
| | - Takasada Shibauchi
- Department of Advanced Materials Science, The University of Tokyo, Kashiwa, 277-8561, Japan
| | - Akihiko Ikeda
- Department of Engineering Science, University of Electro-Communications, Chofu, 182-8585, Japan
| | - Masashi Tokunaga
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, 277-8581, Japan.,RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
| | - Takashi Kurumaji
- Department of Advanced Materials Science, The University of Tokyo, Kashiwa, 277-8561, Japan
| | - Yusuke Tokunaga
- Department of Advanced Materials Science, The University of Tokyo, Kashiwa, 277-8561, Japan
| | - Taka-Hisa Arima
- Department of Advanced Materials Science, The University of Tokyo, Kashiwa, 277-8561, Japan. .,RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan.
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Sale M, Xia Q, Avdeev M, Ling CD. Crystal and Magnetic Structures of Melilite-Type Ba 2MnSi 2O 7. Inorg Chem 2019; 58:4164-4172. [PMID: 30839202 DOI: 10.1021/acs.inorgchem.8b03195] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Melilite-type Ba2MnSi2O7 was synthesized by a standard powder solid-state reaction route, and its magnetic properties were studied at low temperature. The magnetic structure was found to be C-type pointing along the c axis from neutron powder diffraction, which is different from the G-type ordering previously reported in all other 2-2-4-2 melilites with manganese as the B'-site transition metal. Ab initio (density functional theory) and magnetic dipole-dipole calculations were used to understand the magnetic structure by determining the spin supersuperexchange parameters as well as the relative influence of spin-orbit coupling and the magnetic dipole-dipole interactions.
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Affiliation(s)
- Matthew Sale
- Australian Centre for Neutron Scattering , Australian Nuclear Science and Technology Organisation , Sydney , Australia.,School of Chemistry , The University of Sydney , Sydney , Australia
| | - Qingbo Xia
- School of Chemistry , The University of Sydney , Sydney , Australia
| | - Maxim Avdeev
- Australian Centre for Neutron Scattering , Australian Nuclear Science and Technology Organisation , Sydney , Australia.,School of Chemistry , The University of Sydney , Sydney , Australia
| | - Chris D Ling
- School of Chemistry , The University of Sydney , Sydney , Australia
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Endo T, Doi Y, Wakeshima M, Suzuki K, Matsuo Y, Tezuka K, Ohtsuki T, Shan YJ, Hinatsu Y. Magnetic Properties of the Melilite-Type Oxysulfide Sr2MnGe2S6O: Magnetic Interactions Enhanced by Anion Substitution. Inorg Chem 2017; 56:2459-2466. [DOI: 10.1021/acs.inorgchem.6b02505] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | | | - Keitaro Tezuka
- Research
Division of Functional Materials Design, Graduate School of Engineering, Utsunomiya University, Utsunomiya 321-8585, Japan
| | - Takuya Ohtsuki
- Research
Division of Functional Materials Design, Graduate School of Engineering, Utsunomiya University, Utsunomiya 321-8585, Japan
| | - Yue Jin Shan
- Research
Division of Functional Materials Design, Graduate School of Engineering, Utsunomiya University, Utsunomiya 321-8585, Japan
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