Abstract
Magnetic skyrmions as swirling spin textures with a nontrivial topology have potential applications as magnetic memory and storage devices. Since the initial discovery of skyrmions in non-centrosymmetric B20 materials, the recent effort has focused on exploring room-temperature skyrmions in heavy metal and ferromagnetic heterostructures, a material platform compatible with existing spintronic manufacturing technology. Here, we report the surprising observation that a room-temperature skyrmion phase can be stabilized in an entirely different class of systems based on antiferromagnetic (AFM) metal and ferromagnetic (FM) metal IrMn/CoFeB heterostructures. There are a number of distinct advantages of exploring skyrmions in such heterostructures including zero-field stabilization, tunable antiferromagnetic order, and sizable spin-orbit torque (SOT) for energy-efficient current manipulation. Through direct spatial imaging of individual skyrmions, quantitative evaluation of the interfacial Dzyaloshinskii-Moriya interaction, and demonstration of current-driven skyrmion motion, our findings firmly establish the AFM/FM heterostructures as a promising material platform for exploring skyrmion physics and device applications.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 980-986 |
| Number of pages | 7 |
| Journal | Nano letters |
| Volume | 18 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 14 2018 |
Funding
The authors at UCLA and UT-Austin were supported by the Spins and Heat in Nanoscale Electronic Systems (SHINES), an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES) under Award No. SC0012670. The authors at UCLA were also partially supported by the National Science Foundation (ECCS 1611570). The authors at UCLA were also partially supported by CSPIN and FAME, two of six centers of STARnet, a Semiconductor Research Corporation program, sponsored by MARCO and DARPA. The authors at UCLA were also partially sponsored by the Army Research Office and was accomplished under Grant Number W911NF-16-1-0472. The authors at UCLA would like to acknowledge the collaboration of this research with the King Abdul-Aziz City for Science and Technology (KACST) via The Center of Excellence for Green Nanotechnologies (CEGN). The authors at UCSB were supported by an Air Force Office of Scientific Research PECASE award. Probe fabrication was done in the UC Santa Barbara Nanofabrication Facility, part of the NSF funded NNIN network. W.J. was supported by National Key R&D Program of China under contract number 2017YFA0206200, 2016YFA0302300, National Science Foundation of China under contract number 11774194, the 1000- Youth talent program of China, the State Key Laboratory of Low-Dimensional Quantum Physics, the Beijing Advanced Innovation Center for Future Chip (ICFC). G.Y. would like to thank Dr. Wei Zhang for fruitful discussions.
Keywords
- Skyrmion
- antiferromagnet
- exchange bias
- room temperature
- thin films
- zero field
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanical Engineering
- Bioengineering
- General Chemistry
- General Materials Science