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Huai X, Acheampong E, Delles E, Winiarski MJ, Sorolla M, Nassar L, Liang M, Ramette C, Ji H, Scheie A, Calder S, Mourigal M, Tran TT. Noncentrosymmetric Triangular Magnet CaMnTeO 6: Strong Quantum Fluctuations and Role of s 0 versus s 2 Electronic States in Competing Exchange Interactions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2313763. [PMID: 38506567 DOI: 10.1002/adma.202313763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 03/12/2024] [Indexed: 03/21/2024]
Abstract
Noncentrosymmetric triangular magnets offer a unique platform for realizing strong quantum fluctuations. However, designing these quantum materials remains an open challenge attributable to a knowledge gap in the tunability of competing exchange interactions at the atomic level. Here, a new noncentrosymmetric triangular S = 3/2 magnet CaMnTeO6 is created based on careful chemical and physical considerations. The model material displays competing magnetic interactions and features nonlinear optical responses with the capability of generating coherent photons. The incommensurate magnetic ground state of CaMnTeO6 with an unusually large spin rotation angle of 127°(1) indicates that the anisotropic interlayer exchange is strong and competing with the isotropic interlayer Heisenberg interaction. The moment of 1.39(1) µB, extracted from low-temperature heat capacity and neutron diffraction measurements, is only 46% of the expected value of the static moment 3 µB. This reduction indicates the presence of strong quantum fluctuations in the half-integer spin S = 3/2 CaMnTeO6 magnet, which is rare. By comparing the spin-polarized band structure, chemical bonding, and physical properties of AMnTeO6 (A = Ca, Sr, Pb), how quantum-chemical interpretation can illuminate insights into the fundamentals of magnetic exchange interactions, providing a powerful tool for modulating spin dynamics with atomically precise control is demonstrated.
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Affiliation(s)
- Xudong Huai
- Department of Chemistry, Clemson University, Clemson, SC, 29634, USA
| | | | - Erich Delles
- Department of Chemistry, Clemson University, Clemson, SC, 29634, USA
| | - Michał J Winiarski
- Applied Physics and Mathematics and Advanced Materials Center, Gdansk University of Technology, Gdansk, 80-233, Poland
| | - Maurice Sorolla
- Institute of Chemistry, University of the Philippines Diliman, Quezon City, 1101, Philippines
| | - Lila Nassar
- School of Physics, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Mingli Liang
- Department of Chemistry, University of Houston, Houston, TX, 77204, USA
| | - Caleb Ramette
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Huiwen Ji
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Allen Scheie
- MPA-Q, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Stuart Calder
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Martin Mourigal
- School of Physics, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Thao T Tran
- Department of Chemistry, Clemson University, Clemson, SC, 29634, USA
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Kim J, Na W, Kim J, Park P, Zhang K, Hwang I, Son YW, Kim JH, Cheong H, Park JG. Rapid Suppression of Quantum Many-Body Magnetic Exciton in Doped van der Waals Antiferromagnet (Ni,Cd)PS 3. NANO LETTERS 2023; 23:10189-10195. [PMID: 37931216 DOI: 10.1021/acs.nanolett.3c02677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
The unique discovery of the magnetic exciton in van der Waals antiferromagnet NiPS3 arises between two quantum many-body states of a Zhang-Rice singlet excited state and a Zhang-Rice triplet ground state. Simultaneously, the spectral width of photoluminescence originating from this exciton is exceedingly narrow as 0.4 meV. These extraordinary properties, including the extreme coherence of the magnetic exciton in NiPS3, beg many questions. We studied doping effects using Ni1-xCdxPS3 using two experimental techniques and theoretical studies. Our experimental results show that the magnetic exciton is drastically suppressed upon a few % Cd doping. All this happens while the width of the exciton only gradually increases and the antiferromagnetic ground state is robust. These results highlight the lattice uniformity's hidden importance as a prerequisite for coherent magnetic exciton. Finally, an exciting scenario emerges: the broken charge transfer forbids the otherwise uniform formation of the coherent magnetic exciton in (Ni,Cd)PS3.
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Affiliation(s)
- Junghyun Kim
- Center for Quantum Materials, Seoul National University, Seoul 08826, Republic of Korea
- Department of Physics & Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Woongki Na
- Department of Physics, Sogang University, Seoul 04107, Republic of Korea
| | - Jonghyeon Kim
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
| | - Pyeongjae Park
- Center for Quantum Materials, Seoul National University, Seoul 08826, Republic of Korea
- Department of Physics & Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Kaixuan Zhang
- Center for Quantum Materials, Seoul National University, Seoul 08826, Republic of Korea
- Department of Physics & Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Inho Hwang
- Center for Quantum Materials, Seoul National University, Seoul 08826, Republic of Korea
- Department of Physics & Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Young-Woo Son
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul 02455, Republic of Korea
| | - Jae Hoon Kim
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
| | - Hyeonsik Cheong
- Department of Physics, Sogang University, Seoul 04107, Republic of Korea
| | - Je-Geun Park
- Center for Quantum Materials, Seoul National University, Seoul 08826, Republic of Korea
- Department of Physics & Astronomy, Seoul National University, Seoul 08826, Republic of Korea
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