Year: 2024
Type: article
Abstract: The nodal-line semiconductor Mn3Si2Te6 is generating enormous excitment due to the recent discovery of a field-driven insulator-to-metal transition and associated colossal magnetoresistance as well as evidence for a new type of quantum state involving chiral orbital currents. Strikingly, these qualities persist even in the absence of traditional Jahn-Teller distortions and double-exchange mechanisms, raising questions about exactly how and why magnetoresistance occurs along with conjecture as to the likely signatures of loop currents. Here, we measured the infrared response of Mn3Si2Te6 across the magnetic ordering and field-induced insulator-to-metal transitions in order to explore colossal magnetoresistance in the absence of Jahn-Teller and double-exchange interactions. Rather than a traditional metal with screened phonons, the field-driven insulator-to-metal transition leads to a weakly metallic state with localized carriers. Our spectral data are fit by a percolation model, providing evidence for electronic inhomogeneity and phase separation. Modeling also reveals a frequency-dependent threshold field for carriers contributing to colossal magnetoresistance which we discuss in terms of polaron formation, chiral orbital currents, and short-range spin fluctuations. These findings enhance the understanding of insulator-to-metal transitions in new settings and open the door to the design of unconventional colossal magnetoresistant materials. Field-driven insulator-to-metal transition and associated colossal magnetoresistance have been reported in the magnetic nodal-line semiconductor Mn3Si2Te6. Gu et al. measure infrared response across magnetic ordering and the transition, revealing a weakly metallic state instead of a traditional metallic state.
Source: Nature Communications
Institutions: University of Tennessee at Knoxville, University of Minnesota, Pohang University of Science and Technology, Okinawa Institute of Science and Technology Graduate University, Rutgers, The State University of New Jersey, Florida State University, National High Magnetic Field Laboratory, Brookhaven National Laboratory, National Synchrotron Light Source II, Oak Ridge National Laboratory
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,790
Funders: National Science Foundation, U.S. Department of Energy, Gordon and Betty Moore Foundation, University of Minnesota, National High Magnetic Field Laboratory, National Research Foundation, National Research Foundation of Korea, Ministry of Science and ICT, South Korea, Office of Science, Division of Materials Research, Basic Energy Sciences, High Magnetic Field Laboratory, Chinese Academy of Sciences, Brookhaven National Laboratory
Awards: G1019936685, G1285306620, G1847291448, G241279073, G248902062, G3262563802, G330818184, G357145406, G3846980675, Substrate-on-Demand Program: Phase Two, COMPLEX CHALCOGENIDES UNDER PRESSURE, UNIVERSITY OF MINNESOTA CENTER FOR QUANTUM MATERIALS (CQM), G543814473, G5489601777, G5765906131, Theoretical Spectroscopy and Thermodynamics of Correlated Electron Materials, G6965541988, National High Magnetic Field Laboratory Renewal 2023-2027, G742574937, G7463374569, G7493690941, G8152425740, G8618556185, G872144517
OpenAlex ID: W4402580216