Direction-control of anisotropic electronic behaviors via ferroelasticity in two-dimensional α-MPI (M = Zr, Hf)

Directional control of electronic behaviors is highly desirable for developing novel devices. One major obstacle is the lack of feasible means with a switchable manner. Here, we propose that the direction-control of anisotropic electronic behaviors can be achieved via ferroelastic switching. Through first-principles calculations, we reveal that single-layer alpha-MPI (M = Zr, Hf) not only exhibits ultrahigh carrier mobility with an anisotropic character, but also harbors excellent ferroelasticity. The ferroelasticity in single-layer alpha-MPI shows moderate switching barriers and distinct ferroelastic signals, beneficial for its application in memory devices. Meanwhile, the carrier mobility of single-layer alpha-MPI is extremely high in the y direction, while low in the x direction, suggesting that the carriers tend to feature directional migration. Such coexistence indicates that the directional control of carrier migration is achievable in single-layer alpha-MPI by 90 degrees reversible ferroelastic switching. Our findings thus provide an outstanding avenue for designing novel controllable electronic devices.