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Title: Negative electronic compressibility and tunable spin splitting in WSe2

Abstract

We report that tunable bandgaps, extraordinarily large exciton-binding energies, strong light-matter coupling and a locking of the electron spin with layer and valley pseudospins have established transition-metal dichalcogenides (TMDs) as a unique class of two-dimensional (2D) semiconductors with wide-ranging practical applications. Using angle-resolved photoemission (ARPES), we show here that doping electrons at the surface of the prototypical strong spin-orbit TMD WSe2, akin to applying a gate voltage in a transistor-type device, induces a counterintuitive lowering of the surface chemical potential concomitant with the formation of a multivalley 2D electron gas (2DEG). These measurements provide a direct spectroscopic signature of negative electronic compressibility (NEC), a result of electron-electron interactions, which we find persists to carrier densities approximately three orders of magnitude higher than in typical semiconductor 2DEGs that exhibit this effect. An accompanying tunable spin splitting of the valence bands further reveals a complex interplay between single-particle band-structure evolution and many-body interactions in electrostatically doped TMDs. Lastly, understanding and exploiting this will open up new opportunities for advanced electronic and quantum-logic devices.

Authors:
 [1];  [2];  [3];  [4];  [5];  [2];  [6];  [6]; ORCiD logo [7];  [5];  [4];  [8]; ORCiD logo [3]
  1. Univ. of St. Andrews, Scotland (United Kingdom); Diamond Light Source, Harwell Campus, Didcot (United Kingdom)
  2. Suranaree University of Technology, Nakhon Ratchasima (Thailand)
  3. Univ. of St. Andrews, Scotland (United Kingdom)
  4. Tokyo Institute of Technology, Kanagawa (Japan)
  5. Univ. of Tokyo (Japan); Max Planck Institute for Solid State Research, Stuttgart (Germany)
  6. Diamond Light Source, Harwell Campus, Didcot (United Kingdom)
  7. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  8. Univ. of Tokyo (Japan); RIKEN Center for Emergent Matter Science (CEMS), Wako (Japan)
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1530213
Grant/Contract Number:  
AC02-05CH11231
Resource Type:
Accepted Manuscript
Journal Name:
Nature Nanotechnology
Additional Journal Information:
Journal Volume: 10; Journal Issue: 12; Journal ID: ISSN 1748-3387
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Riley, J. M., Meevasana, W., Bawden, L., Asakawa, M., Takayama, T., Eknapakul, T., Kim, T. K., Hoesch, M., Mo, S. -K., Takagi, H., Sasagawa, T., Bahramy, M. S., and King, P. D. C. Negative electronic compressibility and tunable spin splitting in WSe2. United States: N. p., 2015. Web. doi:10.1038/nnano.2015.217.
Riley, J. M., Meevasana, W., Bawden, L., Asakawa, M., Takayama, T., Eknapakul, T., Kim, T. K., Hoesch, M., Mo, S. -K., Takagi, H., Sasagawa, T., Bahramy, M. S., & King, P. D. C. Negative electronic compressibility and tunable spin splitting in WSe2. United States. https://doi.org/10.1038/nnano.2015.217
Riley, J. M., Meevasana, W., Bawden, L., Asakawa, M., Takayama, T., Eknapakul, T., Kim, T. K., Hoesch, M., Mo, S. -K., Takagi, H., Sasagawa, T., Bahramy, M. S., and King, P. D. C. Mon . "Negative electronic compressibility and tunable spin splitting in WSe2". United States. https://doi.org/10.1038/nnano.2015.217. https://www.osti.gov/servlets/purl/1530213.
@article{osti_1530213,
title = {Negative electronic compressibility and tunable spin splitting in WSe2},
author = {Riley, J. M. and Meevasana, W. and Bawden, L. and Asakawa, M. and Takayama, T. and Eknapakul, T. and Kim, T. K. and Hoesch, M. and Mo, S. -K. and Takagi, H. and Sasagawa, T. and Bahramy, M. S. and King, P. D. C.},
abstractNote = {We report that tunable bandgaps, extraordinarily large exciton-binding energies, strong light-matter coupling and a locking of the electron spin with layer and valley pseudospins have established transition-metal dichalcogenides (TMDs) as a unique class of two-dimensional (2D) semiconductors with wide-ranging practical applications. Using angle-resolved photoemission (ARPES), we show here that doping electrons at the surface of the prototypical strong spin-orbit TMD WSe2, akin to applying a gate voltage in a transistor-type device, induces a counterintuitive lowering of the surface chemical potential concomitant with the formation of a multivalley 2D electron gas (2DEG). These measurements provide a direct spectroscopic signature of negative electronic compressibility (NEC), a result of electron-electron interactions, which we find persists to carrier densities approximately three orders of magnitude higher than in typical semiconductor 2DEGs that exhibit this effect. An accompanying tunable spin splitting of the valence bands further reveals a complex interplay between single-particle band-structure evolution and many-body interactions in electrostatically doped TMDs. Lastly, understanding and exploiting this will open up new opportunities for advanced electronic and quantum-logic devices.},
doi = {10.1038/nnano.2015.217},
journal = {Nature Nanotechnology},
number = 12,
volume = 10,
place = {United States},
year = {Mon Sep 21 00:00:00 EDT 2015},
month = {Mon Sep 21 00:00:00 EDT 2015}
}

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Works referenced in this record:

Coupled Spin and Valley Physics in Monolayers of MoS 2 and Other Group-VI Dichalcogenides
journal, May 2012


Compressibility of the two-dimensional electron gas: Measurements of the zero-field exchange energy and fractional quantum Hall gap
journal, July 1994


Many-body effects in n -type Si inversion layers. I. Effects in the lowest subband
journal, May 1976


Interaction phenomena in graphene seen through quantum capacitance
journal, February 2013

  • Yu, G. L.; Jalil, R.; Belle, Branson
  • Proceedings of the National Academy of Sciences, Vol. 110, Issue 9
  • DOI: 10.1073/pnas.1300599110

Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2
journal, December 2013


Occupied and unoccupied electronic band structure of WSe 2
journal, April 1997


Spin and pseudospins in layered transition metal dichalcogenides
journal, April 2014

  • Xu, Xiaodong; Yao, Wang; Xiao, Di
  • Nature Physics, Vol. 10, Issue 5
  • DOI: 10.1038/nphys2942

Electronics and optoelectronics of two-dimensional transition metal dichalcogenides
journal, November 2012

  • Wang, Qing Hua; Kalantar-Zadeh, Kourosh; Kis, Andras
  • Nature Nanotechnology, Vol. 7, Issue 11, p. 699-712
  • DOI: 10.1038/nnano.2012.193

Superconducting Dome in a Gate-Tuned Band Insulator
journal, November 2012


Magnetoelectric effects and valley-controlled spin quantum gates in transition metal dichalcogenide bilayers
journal, June 2013

  • Gong, Zhirui; Liu, Gui-Bin; Yu, Hongyi
  • Nature Communications, Vol. 4, Issue 1
  • DOI: 10.1038/ncomms3053

Emergent quantum confinement at topological insulator surfaces
journal, January 2012

  • Bahramy, M. S.; King, P. D. C.; de la Torre, A.
  • Nature Communications, Vol. 3, Issue 1
  • DOI: 10.1038/ncomms2162

Band Offset and Negative Compressibility in Graphene-MoS 2 Heterostructures
journal, March 2014

  • Larentis, Stefano; Tolsma, John R.; Fallahazad, Babak
  • Nano Letters, Vol. 14, Issue 4
  • DOI: 10.1021/nl500212s

Spectroscopic evidence for negative electronic compressibility in a quasi-three-dimensional spin–orbit correlated metal
journal, April 2015

  • He, Junfeng; Hogan, T.; Mion, Thomas R.
  • Nature Materials, Vol. 14, Issue 6
  • DOI: 10.1038/nmat4273

Carrier Plasmon Induced Nonlinear Band Gap Renormalization in Two-Dimensional Semiconductors
journal, February 2015


Electrically Switchable Chiral Light-Emitting Transistor
journal, April 2014


Probing excitonic dark states in single-layer tungsten disulphide
journal, August 2014

  • Ye, Ziliang; Cao, Ting; O’Brien, Kevin
  • Nature, Vol. 513, Issue 7517
  • DOI: 10.1038/nature13734

Measurement of the quantum capacitance of interacting electrons in carbon nanotubes
journal, September 2006

  • Ilani, S.; Donev, L. A. K.; Kindermann, M.
  • Nature Physics, Vol. 2, Issue 10
  • DOI: 10.1038/nphys412

Atomically Thin MoS2 A New Direct-Gap Semiconductor
journal, September 2010


Large Tunable Rashba Spin Splitting of a Two-Dimensional Electron Gas in Bi 2 Se 3
journal, August 2011


Band-gap renormalization in semiconductor quantum wells
journal, April 1990


Strong light–matter coupling in two-dimensional atomic crystals
journal, December 2014


Tightly bound trions in monolayer MoS2
journal, December 2012

  • Mak, Kin Fai; He, Keliang; Lee, Changgu
  • Nature Materials, Vol. 12, Issue 3
  • DOI: 10.1038/nmat3505

Negative compressibility of interacting two-dimensional electron and quasiparticle gases
journal, February 1992


Very Large Capacitance Enhancement in a Two-Dimensional Electron System
journal, May 2011


Quasiparticle dynamics and spin–orbital texture of the SrTiO3 two-dimensional electron gas
journal, February 2014

  • King, P. D. C.; McKeown Walker, S.; Tamai, A.
  • Nature Communications, Vol. 5, Issue 1
  • DOI: 10.1038/ncomms4414

Ambipolar MoS 2 Thin Flake Transistors
journal, February 2012

  • Zhang, Yijin; Ye, Jianting; Matsuhashi, Yusuke
  • Nano Letters, Vol. 12, Issue 3
  • DOI: 10.1021/nl2021575

Direct observation of spin-polarized bulk bands in an inversion-symmetric semiconductor
journal, October 2014

  • Riley, J. M.; Mazzola, F.; Dendzik, M.
  • Nature Physics, Vol. 10, Issue 11
  • DOI: 10.1038/nphys3105

Gate Control of Spin-Orbit Interaction in an Inverted I n 0.53 G a 0.47 As/I n 0.52 A l 0.48 As Heterostructure
journal, February 1997


Giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
journal, August 2014

  • Ugeda, Miguel M.; Bradley, Aaron J.; Shi, Su-Fei
  • Nature Materials, Vol. 13, Issue 12
  • DOI: 10.1038/nmat4061

Maximally localized Wannier functions for entangled energy bands
journal, December 2001


Zeeman-type spin splitting controlled by an electric field
journal, July 2013

  • Yuan, Hongtao; Bahramy, Mohammad Saeed; Morimoto, Kazuhiro
  • Nature Physics, Vol. 9, Issue 9
  • DOI: 10.1038/nphys2691

Large Tunable Rashba Spin Splitting of a Two-Dimensional Electron Gas in Bi2Se3
text, January 2011

  • P., King,; R., Hatch,; M., Bianchi,
  • American Physical Society
  • DOI: 10.5167/uzh-49251

Band offset and negative compressibility in graphene-MoS2 heterostructures
text, January 2014


Quasiparticle dynamics and spin-orbital texture of the SrTiO3 two-dimensional electron gas
text, January 2014


Probing Excitonic Dark States in Single-layer Tungsten Disulfide
text, January 2014


Maximally-localized Wannier functions for entangled energy bands
text, January 2001


Works referencing / citing this record:

Room‐Temperature Mesoscopic Fluctuations and Coulomb Drag in Multilayer WSe 2
journal, March 2019

  • Doan, Manh‐Ha; Jin, Youngjo; Chau, Tuan Khanh
  • Advanced Materials, Vol. 31, Issue 17
  • DOI: 10.1002/adma.201900154

Spin–valley locking in the normal state of a transition-metal dichalcogenide superconductor
journal, May 2016

  • Bawden, L.; Cooil, S. P.; Mazzola, F.
  • Nature Communications, Vol. 7, Issue 1
  • DOI: 10.1038/ncomms11711

Large quantum-spin-Hall gap in single-layer 1T′ WSe2
journal, May 2018


Holstein polaron in a valley-degenerate two-dimensional semiconductor
journal, May 2018


Giant spin-splitting and gap renormalization driven by trions in single-layer WS2/h-BN heterostructures
journal, January 2018


Visualizing electronic structures of quantum materials by angle-resolved photoemission spectroscopy
journal, August 2018


Visualizing electrostatic gating effects in two-dimensional heterostructures
journal, July 2019


Controlling the surface photovoltage on WSe 2 by surface chemical modification
journal, May 2018

  • Liu, Ro-Ya; Ozawa, Kenichi; Terashima, Naoya
  • Applied Physics Letters, Vol. 112, Issue 21
  • DOI: 10.1063/1.5026351

Semiconductor-to-metal transition in the bulk of WSe 2 upon potassium intercalation
journal, March 2017

  • Ahmad, Mushtaq; Müller, Eric; Habenicht, Carsten
  • Journal of Physics: Condensed Matter, Vol. 29, Issue 16
  • DOI: 10.1088/1361-648x/aa63a7

Negative electron compressibility in the Hubbard model
journal, December 2019


Two-dimensional hexagonal semiconductors beyond graphene
journal, September 2016

  • Nguyen, Bich Ha; Nguyen, Van Hieu
  • Advances in Natural Sciences: Nanoscience and Nanotechnology, Vol. 7, Issue 4
  • DOI: 10.1088/2043-6262/7/4/043001

Quantum supercapacitors
journal, August 2019


Direct observation of strain-induced orbital valence band splitting in HfSe 2 by sodium intercalation
journal, May 2018


Band-Gap-Dependent Electronic Compressibility of Carbon Nanotubes in the Wigner Crystal Regime
journal, November 2019


A Perspective on the Application of Spatially Resolved ARPES for 2D Materials
journal, April 2018


Semiconductor-to-Metal Transition in the Bulk of WSe2 upon Potassium Intercalation
text, January 2017


Holstein polaron in a valley-degenerate two-dimensional semiconductor
text, January 2018


Large quantum-spin-Hall gap in single-layer 1T′ WSe2
journal, May 2018


Determination of the band parameters of bulk 2H-MX2 (M = Mo, W; X = S, Se) by angle-resolved photoemission spectroscopy
journal, November 2016

  • Kim, Beom Seo; Rhim, Jun-Won; Kim, Beomyoung
  • Scientific Reports, Vol. 6, Issue 1
  • DOI: 10.1038/srep36389

Angle-resolved photoemission spectroscopy for the study of two-dimensional materials
journal, March 2017