APS March Meeting 2014
Volume 59, Number 1
Monday–Friday, March 3–7, 2014;
Denver, Colorado
Session Y48: Invited Session: Spin Transport in Novel 2d Electronic Systems
8:00 AM–10:24 AM,
Friday, March 7, 2014
Room: Mile High Ballroom 1A-1B
Sponsoring
Units:
GMAG DCMP
Chair: Berend Jonker, Naval Research Laboratory
Abstract ID: BAPS.2014.MAR.Y48.4
Abstract: Y48.00004 : Layered Chalcogenides beyond Graphene: from Electronic Structure Evolution to the Spin Transport
9:48 AM–10:24 AM
Preview Abstract
Abstract
Author:
Hongtao Yuan
(Geballe Laboratory for Advanced Materials, Stanford University)
Recent efforts on graphene-like atomic layer materials, aiming at novel
electronic properties and quantum phenomena beyond graphene, have attracted
much attention for potential electronics/spintronics applications. Compared
to the weak spin-orbit-interaction (SOI) in graphene, metal chalcogenides
MX$_{\mathrm{2}}$ have heavy 4d/5d elements with strong atomic SOI,
providing a unique way for generating spin polarization based on
valleytronics physics. Indeed, such a spin-polarized band structure has been
demonstrated theoretically and supported by optical investigations. However,
despite these exciting progresses, following two important issues in
MX$_{\mathrm{2}}$ community remain elusive: 1. the quantitative band
structure of MX$_{\mathrm{2}}$ compounds (where are the valleys -band
maxima/minima- locating in the BZ) have not been experimentally confirmed.
Especially for those cleaved ultrathin mono- and bi-layer flakes hosting
most of recently-reported exotic phenomena at the 2D limit, the direct
detection for band dispersion becomes of great importance for valleytronics.
2. Spin transports have seldom been reported even though such a strong SOI
system can serve as an ideal platform for the spin polarization and spin
transport. In this work, we started from the basic electronic structures of
representative MX$_{\mathrm{2}}$, obtained by ARPES, and investigated both
the band variation between these compounds and their band evolution from
bulk to the monolayer limit. After having a systematic understanding on band
structures, we reported a giant Zeeman-type spin-polarization generated and
modulated by an external electric field in WSe$_{\mathrm{2}}$
electric-double-layer transistors. The non-magnetic approach for realizing
such an intriguing spin splitting not only keeps the system time-reversally
invariant but also suggests a new paradigm for manipulating the spin-degrees
of freedom of electrons.
Acknowledge the support from DoE, BES, Division of MSE under contract
DE-AC02-76SF00515.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2014.MAR.Y48.4