skip to main content

DOE PAGESDOE PAGES

Title: Electrical control of second-harmonic generation in a WSe2 monolayer transistor

Nonlinear optical frequency conversion, in which optical fields interact with a nonlinear medium to produce new field frequencies, is ubiquitous in modern photonic systems. However, the nonlinear electric susceptibilities that give rise to such phenomena are often challenging to tune in a given material and, so far, dynamical control of optical nonlinearities remains confined to research laboratories as a spectroscopic tool. In this paper, we report a mechanism to electrically control second-order optical nonlinearities in monolayer WSe2, an atomically thin semiconductor. We show that the intensity of second-harmonic generation at the A-exciton resonance is tunable by over an order of magnitude at low temperature and nearly a factor of four at room temperature through electrostatic doping in a field-effect transistor. Such tunability arises from the strong exciton charging effects in monolayer semiconductors, which allow for exceptional control over the oscillator strengths at the exciton and trion resonances. The exciton-enhanced second-harmonic generation is counter-circularly polarized to the excitation laser due to the combination of the two-photon and one-photon valley selection rules, which have opposite helicity in the monolayer. Finally, our study paves the way towards a new platform for chip-scale, electrically tunable nonlinear optical devices based on two-dimensional semiconductors.
Authors:
 [1] ;  [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [3] ;  [4] ;  [2] ;  [5]
  1. Univ. of Washington, Seattle, WA (United States). Dept. of Physics
  2. Univ. of Hong Kong (China). Dept. of Physics and Center of Theoretical and Computational Physics
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics and Astronomy
  5. Univ. of Washington, Seattle, WA (United States). Dept. of Physics; Univ. of Washington, Seattle, WA (United States). Dept. of Materials Science and Engineering
Publication Date:
OSTI Identifier:
1265564
Grant/Contract Number:
SC0008145; SC0012509; DMR-1150719; HKU705513P; HKU9/CRF/13G; AoE/P-04/08
Type:
Accepted Manuscript
Journal Name:
Nature Nanotechnology
Additional Journal Information:
Journal Volume: 10; Journal Issue: 5; Journal ID: ISSN 1748-3387
Publisher:
Nature Publishing Group
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF) (United States); Research Grant Council of Hong Kong (China); University Grant Council of Hong Kong (China)
Contributing Orgs:
Univ. of Washington, Seattle, WA (United States); Univ. of Hong Kong (China)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 36 MATERIALS SCIENCE nanophotonics and plasmonics; nonlinear optics; two-dimensional materials