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Title: Efficient generation of neutral and charged biexcitons in encapsulated WSe 2 monolayers

Abstract

Optical nonlinearity of excitons arises from their mutual interactions, which generally requires a significant exciton density and therefore high excitation levels. Here, we report the emergence of two biexcitons species, one neutral and one charged, in monolayer tungsten diselenide under moderate continuous-wave excitation. The efficient biexciton formation is facilitated by a long lifetime of the dark exciton associated with a spin-forbidden transition, as well as improved sample quality from encapsulation by hexagonal boron nitride layers. From studies of the polarization and magnetic field dependence of the neutral biexciton, we conclude that this species is composed of a bright and a dark exciton residing in opposite valleys in momentum space. Lastly, our observations demonstrate that the distinctive features associated with biexciton states can be accessed at low light intensities and excitation densities.

Authors:
 [1];  [2];  [2];  [3];  [3];  [3];  [2];  [2];  [4];  [5];  [4];  [6];  [6];  [3];  [7]
  1. Stanford Univ., Stanford, CA (United States); Univ. of British Columbia, Vancouver, BC (Canada)
  2. Stanford Univ., Stanford, CA (United States)
  3. Columbia Univ., New York, NY (United States)
  4. National High Magnetic Field Lab., Tallahassee, FL (United States)
  5. National High Magnetic Field Lab., Tallahassee, FL (United States); Florida State Univ., Tallahassee, FL (United States)
  6. National Institute for Materials Science, Tsukuba (Japan)
  7. Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1469032
Alternate Identifier(s):
OSTI ID: 1463000
Report Number(s):
SLAC-PUB-17316
Journal ID: ISSN 2041-1723; TRN: US1902245
Grant/Contract Number:  
AC02-76SF00515; GBMF4545; FG02-07ER46451
Resource Type:
Published Article
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 9; Journal Issue: 1; Journal ID: ISSN 2041-1723
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Ye, Ziliang, Waldecker, Lutz, Ma, Eric Yue, Rhodes, Daniel, Antony, Abhinandan, Kim, Bumho, Zhang, Xiao -Xiao, Deng, Minda, Jiang, Yuxuan, Lu, Zhengguang, Smirnov, Dmitry, Watanabe, Kenji, Taniguchi, Takashi, Hone, James, and Heinz, Tony F. Efficient generation of neutral and charged biexcitons in encapsulated WSe2 monolayers. United States: N. p., 2018. Web. doi:10.1038/s41467-018-05917-8.
Ye, Ziliang, Waldecker, Lutz, Ma, Eric Yue, Rhodes, Daniel, Antony, Abhinandan, Kim, Bumho, Zhang, Xiao -Xiao, Deng, Minda, Jiang, Yuxuan, Lu, Zhengguang, Smirnov, Dmitry, Watanabe, Kenji, Taniguchi, Takashi, Hone, James, & Heinz, Tony F. Efficient generation of neutral and charged biexcitons in encapsulated WSe2 monolayers. United States. doi:10.1038/s41467-018-05917-8.
Ye, Ziliang, Waldecker, Lutz, Ma, Eric Yue, Rhodes, Daniel, Antony, Abhinandan, Kim, Bumho, Zhang, Xiao -Xiao, Deng, Minda, Jiang, Yuxuan, Lu, Zhengguang, Smirnov, Dmitry, Watanabe, Kenji, Taniguchi, Takashi, Hone, James, and Heinz, Tony F. Thu . "Efficient generation of neutral and charged biexcitons in encapsulated WSe2 monolayers". United States. doi:10.1038/s41467-018-05917-8.
@article{osti_1469032,
title = {Efficient generation of neutral and charged biexcitons in encapsulated WSe2 monolayers},
author = {Ye, Ziliang and Waldecker, Lutz and Ma, Eric Yue and Rhodes, Daniel and Antony, Abhinandan and Kim, Bumho and Zhang, Xiao -Xiao and Deng, Minda and Jiang, Yuxuan and Lu, Zhengguang and Smirnov, Dmitry and Watanabe, Kenji and Taniguchi, Takashi and Hone, James and Heinz, Tony F.},
abstractNote = {Optical nonlinearity of excitons arises from their mutual interactions, which generally requires a significant exciton density and therefore high excitation levels. Here, we report the emergence of two biexcitons species, one neutral and one charged, in monolayer tungsten diselenide under moderate continuous-wave excitation. The efficient biexciton formation is facilitated by a long lifetime of the dark exciton associated with a spin-forbidden transition, as well as improved sample quality from encapsulation by hexagonal boron nitride layers. From studies of the polarization and magnetic field dependence of the neutral biexciton, we conclude that this species is composed of a bright and a dark exciton residing in opposite valleys in momentum space. Lastly, our observations demonstrate that the distinctive features associated with biexciton states can be accessed at low light intensities and excitation densities.},
doi = {10.1038/s41467-018-05917-8},
journal = {Nature Communications},
number = 1,
volume = 9,
place = {United States},
year = {2018},
month = {9}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1038/s41467-018-05917-8

Citation Metrics:
Cited by: 16 works
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