Strain-induced electronic state modulation in epitaxial Bi(110) on two-dimensional ferromagnet Fe₃GeTe₂

Precise control of lattice strain and buckling geometry at the nanoscale enables deterministic manipulation of the electronic properties of quantum Bi(110)/Fe3GeTe2 materials. Low dimensional Bi(110) possesses topological properties and ferroelectricity, which are strongly tied to its atomic structure. Here, by fabricating an epitaxial heterostructure composed of 2–3 bilayer Bi(110) in black phosphorus (BP) structure and Fe₃GeTe₂ with hexagonal lattice structure, heterostrain and periodical variation of buckling height h are 2 nm introduced into Bi(110) via interlayer interactions. Modulation of the elec- S(r) tronic states and bandgap of ultra-thin Bi(110) are revealed the study of 1.2 H scanning tunneling microscopy and spectroscopy. The regulation of the _Zero strain 0.6 electronic properties of Bi(110) by lattice stress and magnetic proximity 0 ^Strain Zero strain effect of Fe₃GeTe₂ substrate are further explained by density functional Strain −0.6 theory calculations. The atomic scale straintronics method offers a strategy 2 nm to modify the electronic properties of ultra-thin epitaxial films with poten- ₋7 % −1.2 L 0 5 10 15 20 Strain Distance (nm) tial applications in spintronics and nanoelectronics.