High-temperature concomitant metal-insulator and spin-reorientation transitions in a compressed nodal-line ferrimagnet Mn<sub>3</sub>Si<sub>2</sub>Te<sub>6</sub>.

Susilo, Resta A; Kwon, Chang Il; Lee, Yoonhan; Salke, Nilesh P; De, Chandan; Seo, Junho; Kang, Beomtak; Hemley, Russell J et al. · Nat Commun · 2024

basic_science · Level V

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Abstract

Symmetry-protected band degeneracy, coupled with a magnetic order, is the key to realizing novel magnetoelectric phenomena in topological magnets. While the spin-polarized nodal states have been identified to introduce extremely-sensitive electronic responses to the magnetic states, their possible role in determining magnetic ground states has remained elusive. Here, taking external pressure as a control knob, we show that a metal-insulator transition, a spin-reorientation transition, and a structural modification occur concomitantly when the nodal-line state crosses the Fermi level in a ferrimagnetic semiconductor Mn<sub>3</sub>Si<sub>2</sub>Te<sub>6</sub>. These unique pressure-driven magnetic and electronic transitions, associated with the dome-shaped T<sub>c</sub> variation up to nearly room temperature, originate from the interplay between the spin-orbit coupling of the nodal-line state and magnetic frustration of localized spins. Our findings highlight that the nodal-line states, isolated from other trivial states, can facilitate strongly tunable magnetic properties in topological magnets.