Control of valley polarization in monolayer MoS2 by optical helicity

Kin Fai Mak, Keliang He, Jie Shan, Tony F. Heinz

Research output: Contribution to journalArticle

2146 Scopus citations

Abstract

Electronic and spintronic devices rely on the fact that free charge carriers in solids carry electric charge and spin. There are, however, other properties of charge carriers that might be exploited in new families of devices. In particular, if there are two or more minima in the conduction band (or maxima in the valence band) in momentum space, and if it is possible to confine charge carriers in one of these valleys, then it should be possible to make a valleytronic device. Valley polarization, as the selective population of one valley is designated, has been demonstrated using strain and magnetic fields, but neither of these approaches allows dynamic control. Here, we demonstrate that optical pumping with circularly polarized light can achieve complete dynamic valley polarization in monolayer MoS2 (refs 11, 12), a two-dimensional non-centrosymmetric crystal with direct energy gaps at two valleys. Moreover, this polarization is retained for longer than 1 ns. Our results, and similar results by Zeng et al., demonstrate the viability of optical valley control and suggest the possibility of valley-based electronic and optoelectronic applications in MoS2 monolayers.

Original languageEnglish (US)
Pages (from-to)494-498
Number of pages5
JournalNature nanotechnology
Volume7
Issue number8
DOIs
StatePublished - Aug 2012

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Atomic and Molecular Physics, and Optics
  • Biomedical Engineering
  • Materials Science(all)
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Control of valley polarization in monolayer MoS<sub>2</sub> by optical helicity'. Together they form a unique fingerprint.

  • Cite this