2 research outputs found
Spin–Orbit Torques and Magnetization Switching in (Bi,Sb)<sub>2</sub>Te<sub>3</sub>/Fe<sub>3</sub>GeTe<sub>2</sub> Heterostructures Grown by Molecular Beam Epitaxy
Topological
insulators (TIs) hold promise for manipulating the
magnetization of a ferromagnet (FM) through the spin–orbit
torque (SOT) mechanism. However, integrating TIs with conventional
FMs often leads to significant device-to-device variations and a broad
distribution of SOT magnitudes. In this work, we present a scalable
approach to grow a full van der Waals FM/TI heterostructure by molecular
beam epitaxy, combining the charge-compensated TI (Bi,Sb)2Te3 with 2D FM Fe3GeTe2 (FGT).
Harmonic magnetotransport measurements reveal that the SOT efficiency
exhibits a non-monotonic temperature dependence and experiences a
substantial enhancement with a reduction of the FGT thickness to 2
monolayers. Our study further demonstrates that the magnetization
of ultrathin FGT films can be switched with a current density of Jc ∼ 1010 A/m2,
with minimal device-to-device variations compared to previous investigations
involving traditional FMs
Bilinear magnetoresistance in HgTe topological insulator: opposite signs at opposite surfaces demonstrated by gate control
Abstract Spin-orbit effects appearing in topological insulators (TI) and at Rashba interfaces are currently revolutionizing how we can manipulate spins and have led to several newly discovered effects, from spin-charge interconversion and spin-orbit torques to novel magnetoresistance phenomena. In particular, a puzzling magnetoresistance has been evidenced, bilinear in electric and magnetic fields. Here, we report the observation of bilinear magnetoresistance (BMR) in strained HgTe, a prototypical TI. We show that both the amplitude and sign of this BMR can be tuned by controling, with an electric gate, the relative proportions of the opposite contributions of opposite surfaces. At magnetic fields of 1 T, the magnetoresistance is of the order of 1 \% and has a larger figure of merit than previously measured TIs. We propose a theoretical model giving a quantitative account of our experimental data. This phenomenon, unique to TI, offer novel opportunities to tune the electrical response of surface states for spintronics