Gate-Tunable Renormalization of Spin-Correlated Flat-Band States and Bandgap in a 2D Magnetic Insulator.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37552585.
- Also identified by DOI 10.1021/acsnano.3c01038.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Emergent quantum phenomena in two-dimensional van der Waal (vdW) magnets are largely governed by the interplay between exchange and Coulomb interactions. The ability to precisely tune the Coulomb interaction enables the control of spin-correlated flat-band states, band gap, and unconventional magnetism in such strongly correlated materials. Here, we demonstrate a gate-tunable renormalization of spin-correlated flat-band states and bandgap in magnetic chromium tribromide (CrBr<sub>3</sub>) monolayers grown on graphene. Our gate-dependent scanning tunneling spectroscopy (STS) studies reveal that the interflat-band spacing and bandgap of CrBr<sub>3</sub> can be continuously tuned by 120 and 240 meV, respectively, <i>via</i> electrostatic injection of carriers into the hybrid CrBr<sub>3</sub>/graphene system. This can be attributed to the self-screening of CrBr<sub>3</sub> arising from the gate-induced carriers injected into CrBr<sub>3</sub>, which dominates over the weakened remote screening of the graphene substrate due to the decreased carrier density in graphene. Precise tuning of the spin-correlated flat-band states and bandgap in 2D magnets <i>via</i> electrostatic modulation of Coulomb interactions not only provides effective strategies for optimizing the spin transport channels but also may exert a crucial influence on the exchange energy and spin-wave gap, which could raise the critical temperature for magnetic order.