Topological Spintronics

Departments: Applied Physics
Time: Wednesday, February 23, 2022 - 1:00pm - 2:00pm
Type: Seminar Series
Presenter: Nitin Samarth, Ph.D.
Room/Office: Zoom
Location:

Yale University
Department of Applied Physics

Applied Physics Seminar Series

Topological Spintronics

Topological states often arise in condensed matter systems be- cause of the confluence of strong spin-orbit coupling and some fundamental symmetry (such as time reversal invariance). This can lead to electronic states in which spin and momentum are correlated. The notion of ‘topological spintronics’ began with the intuition that spin-momentum correlation in the helical Dirac surface states of topological insulators might be efficiently ex- ploited for spintronic devices that rely on efficient spin-charge interconversion [1]. This talk provides an overview of the cur- rent state of this field which is a fascinating (and yet sometimes frustrating) mix of technologically attractive spintronic device performance and unresolved fundamental issues (such as the role of bulk-surface correspondence). By synthesizing epitaxi- al topological insulator/ferrimagnetic insulator heterostructures [2,3], we examine the optimal conditions under which efficient spin-charge conversion occurs in a topological insulator. We also discuss recent experiments that examine whether Dirac and Weyl fermions in topological semimetals such as Cd3As2, ZrTe2, and TaAs might provide an attractive route toward ener- gy efficient spintronic devices [4,5,6].

This work is sponsored in part by SMART, a funded center of nCORE, a Semiconductor Research Corporation (SRC) program sponsored by NIST, the Institute for Quantum Matter under DOE EFRC grant DE-SC0019331, and the Penn State Two-Dimensional Crystal Consortium-Materials Innova- tion Platform (2DCC-MIP) under NSF Grant No. DMR- 1539916.

1. A. R. Mellnik, et al., Nature 511, 449 (2014).
2. Hailong Wang et al., Phys. Rev. Lett. 117, 076601 (2016).
3. Hailong Wang et al., Phys. Rev. Res. 1, 012014 (R) (2019).
4. W. Yanez, Y. Ou, et al., Phys. Rev. Applied 16, 054031 (2021). 5. Y. Ou et al., arXiv:2107.08599.
6. W. Yanez, Y. Ou, et al., (in preparation)

Wednesday, February 23, 2022
1:00 PM Via Zoom

Meeting ID: 947 2015 4098
Password: 604783

Hosted By: Peter Schiffer