Generation of high-density biskyrmions by electric current

Abstract

Much interest has been focused on the manipulation of magnetic skyrmions, including the generation, annihilation, and motion behaviors, for potential applications in spintronics. Here, we experimentally demonstrate that a high-density Bloch-type biskyrmion lattice in MnNiGa can be generated by applying electric current. It is revealed that the density of biskyrmions can be remarkably increased by increasing the electric current, in contrast to the scattered biskyrmions induced by a magnetic field alone. Furthermore, the transition from the ferromagnetic state to the stripe domain structure can be terminated by the electric current, leading to the biskyrmions dominated residual domain pattern. These biskyrmions in such residual domain structure are extremely stable at zero magnetic and electric fields and can further evolve into the high-density biskyrmion lattice over a temperature range from 100 to 330 K. Our experimental findings open up a new pathway for the generation of skyrmion lattice by electric current manipulation.

Skyrmion-electronics: writing, deleting, reading and processing magnetic skyrmions toward spintronic applications

“…14(c)], and realized the current-driven motion of biskyrmions. Recent years, more experiments works revealed the rich dynamics of biskyrmions in different type of magnetic materials [235][236][237][238]. However, Loudon et al pointed out in a recent report that the images of biskyrmions observed by LTEM can be explained as type-II magnetic bubbles viewed at an angle to their axes [239].…”

Magnetic field gradient driven dynamics of isolated skyrmions and antiskyrmions in frustrated magnets

“…It is noted that spin-polarized current may not drive the skyrmion well for insulating materials [41], and other control parameters such as field gradient are preferred. In chiral magnets, for example, the gradient can induce a Hall-like motion of skyrmions, i. e., the main velocity v ⊥ (perpendicular to the gradient direction) is induced by the gradient, and a low velocity v || (parallel to the gradient direction) is induced by the damping effect.…”

Stripe domains reorientation in ferromagnetic films with perpendicular magnetic anisotropy

“…The subject is currently attracting wide interest, thanks to the central role played today by magnetic thin films with PMA in many applications, from memories to logic devices and sensors [52]. Current active research on PMA films and multilayers is focused onto the definition of magnetic phase diagrams into different systems where magnetic stripe and skyrmion or bubble phases compete [30,47,50,[53][54][55][56][57]. Nanoscale magnetic textures are today the focus of a wide area of research, thanks to the possibility of generating and controlling the propagation of domains, bubbles, skyrmions and other kinds of spin textures for realizing, e.g.…”

“…logic circuits, racetrack memories, sensors and rf devices [58][59][60][61]. Different methods have been pursued for the generation and controlled propagation, including magnetic field, electric current, electric field or mechanical stress [56,59,[62][63][64][65][66]. In some cases, the geometry and local asymmetries of stripe domain patterns have been used to guide the propagation of skyrmions or bubbles [66,67].…”