Public Abstract

DE-SC0016424: Interfacial Magnetic Skyrmions and Proximity Effects

Award Status: Inactive

Institution: University of New Hampshire, Durham, NH
UEI: GBNGC495XA67
DUNS: 111089470

Most Recent Award Date: 07/19/2018
Number of Support Periods: 3
PM: Fitzsimmons, Timothy

Current Budget Period: 08/15/2018 - 08/14/2019
Current Project Period: 08/15/2016 - 08/14/2019
PI: Zang, Jiadong

Supplement Budget Period: N/A

Public Abstract

Despite being thousands of years old, the subject of magnetism is vibrant and full of surprise. It has been long believed that neighboring magnetic moments in magnetic materials are either parallel, giving rise to ferromagnets, or antiparallel, giving rise to antiferromagnets. However, it was recently confirmed that in magnets with broken inversion symmetry, neighboring spins are neither parallel nor antiparallel, but form an angle determined by magnetic interactions. Once subjected into a magnetic field, a new type of magnetic texture, known as the magnet skyrmion, is emergent. Each skyrmion’s magnetic moments point in all directions, and realize a one-to-one correspondence to a unit sphere, enabling its nontrivial topology, which is extraordinarily stable. Magnetic skyrmions have been observed at the interface of magnetic multilayers at room temperature. At sizes of just 1~100nm, and driven by a current only 6 orders of magnitude smaller than those for domain walls, skyrmions are promising options for the next generation ultralow dissipative memory and logics. To expand upon the new field of skyrmionics and ultimately lower energy use, this research will systematically investigate the correlation between the topology, formation, and dynamics of interfacial skyrmions through theoretical modeling. One important goal of the work is to achieve precise control of single skyrmion creation, which will be realized by spin polarized current and geometric confinement. Once realized, a second goal will be to manipulate the created skyrmion by spin waves and phonon propagations to create prototype information processing and fine tuning by band engineering of proximity semiconductors. High performance graphic processing unit-based Monte Carlo and micromagnetic simulations will be used to explore the interplay between skyrmion dynamics and topological insulators, where topology in both real and reciprocal space may give rise to new features of electron transport. A new algorithm coupling the electron quantum transport and magnetization dynamics will be developed to investigate energy efficiency. A coupled experimental effort will be used to validate theory and will be based on thin film synthesis, magnetometry measurements and magnetic imaging led by Dr. Hoffmann, at the Magnetic Thin Film group at Argonne National Laboratory.

Despite being thousands of years old, the subject of magnetism is vibrant and full of surprise. It has been long believed that neighboring magnetic moments in magnetic materials are either parallel, giving rise to ferromagnets, or antiparallel, giving rise to antiferromagnets. However, it was recently confirmed that in magnets with broken inversion symmetry, neighboring spins are neither parallel nor antiparallel, but form an angle determined by magnetic interactions. Once subjected into a magnetic field, a new type of magnetic texture, known as the magnet skyrmion, is emergent. Each skyrmion’s magnetic moments point in all directions, and realize a one-to-one correspondence to a unit sphere, enabling its nontrivial topology, which is extraordinarily stable. Magnetic skyrmions have been observed at the interface of magnetic multilayers at room temperature. At sizes of just 1~100nm, and driven by a current only 6 orders of magnitude smaller than those for domain walls, skyrmions are promising options for the next generation ultralow dissipative memory and logics.

To expand upon the new field of skyrmionics and ultimately lower energy use, this research will systematically investigate the correlation between the topology, formation, and dynamics of interfacial skyrmions through theoretical modeling. One important goal of the work is to achieve precise control of single skyrmion creation, which will be realized by spin polarized current and geometric confinement. Once realized, a second goal will be to manipulate the created skyrmion by spin waves and phonon propagations to create prototype information processing and fine tuning by band engineering of proximity semiconductors. High performance graphic processing unit-based Monte Carlo and micromagnetic simulations will be used to explore the interplay between skyrmion dynamics and topological insulators, where topology in both real and reciprocal space may give rise to new features of electron transport. A new algorithm coupling the electron quantum transport and magnetization dynamics will be developed to investigate energy efficiency. A coupled experimental effort will be used to validate theory and will be based on thin film synthesis, magnetometry measurements and magnetic imaging led by Dr. Hoffmann, at the Magnetic Thin Film group at Argonne National Laboratory.