Terahertz two-dimensional antiferromagnetic spintronics
Abstract
One of the best candidates for next-generation computer random-access memory is the magnetic device, based on a thin layer of a magnetic layer. The logical 1 and 0 correspond to the moment inside the magnetic layer pointing in different - typically opposite - directions. The moment direction, in turn, is controlled by applying electric fields. While the magnetic layer in memory devices is a ferromagnet such as cobalt or iron, in which all the electron spins point along the same direction, recent experiments have started to use antiferromagnets, where the electron spins point in opposite directions on each atomic lattice site. Antiferromagnetic deviceshave great promise - they can potentially operate at terahertz frequencies, three orders of magnitude faster than ferromagnetic devices, and they can be miniaturized down to near-atomic scale while retaining their stability. However, antiferromagnets are more difficult to read and write than ferromagnets, and the mechanisms of controlling antiferromagnetic spins are not well understood. In this project, we will use electric field to switch the memory state, and use terahertz and optics to do the read-out. These are layered materials, where we can make atomically thin devices by exfoliating flakes with scotch tape. We will switch the antiferromagnetic spins with electric field and then image the switching with optical techniques. We shoot laser light at the device and measure the amount of light generated inside the material at twice the frequency (second-harmonic generation). This technique is sensitive to thelocal spin orientation, therefore they will be sensitive to switching. This project will contribute to better understanding of antiferromagnetic switching, potentially paving the way towards stable terahertz spintronic devices for the next generation wireless communication well beyond 5G.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 15, 2023
- Source ID
- N000142412064
Entities
People
- Liang Wu
Organizations
- Office of Naval Research
- United States Navy
- University of Pennsylvania