Large magnetoelectric resistance in the topological Dirac semimetal α-Sn

Abstract

The spin-momentum locking of surface states in topological materials can produce a resistance that scales linearly with magnetic and electric fields. Such a bilinear magnetoelectric resistance (BMER) effect offers a new approach for information reading and field sensing applications, but the effects demonstrated so far are too weak or for low temperatures. This article reports the first observation of BMER effects in topological Dirac semimetals; the BMER responses were measured at room temperature and were substantially stronger than those reported previously. The experiments used topological Dirac semimetal α-Sn thin films grown on silicon substrates. The films showed BMER responses that are 10 6 times larger than previously measured at room temperature and are also larger than those previously obtained at low temperatures. These results represent a major advance toward realistic BMER applications. Significantly, the data also yield the first characterization of three-dimensional Fermi-level spin texture of topological surface states in α-Sn.

Observation of the Unidirectional Magnetoresistance in Antiferromagnetic Insulator Fe2O3/Pt Bilayers

“…As the UMR increases almost linearly with the magnetic field, another explanation may be the bilinear magnetoelectrical resistance (BMER), where the magnetoresistance changes linearly with both magnetic and electrical fields. [ 34–36 ] However, the control measurement with 5 nm Pt on Al 2 O 3 substrate does not observe any signal, as shown in Figure 2(e), suggesting that the α ‐Fe 2 O 3 layer is required for the existence of UMR.…”