Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Electrical control of charged carriers and excitons in atomically thin materials

Abstract

Electrical confinement and manipulation of charge carriers in semiconducting nanostructures are essential for realizing functional quantum electronic devices1,2,3. The unique band structure4,5,6,7 of atomically thin transition metal dichalcogenides (TMDs) offers a new route towards realizing novel 2D quantum electronic devices, such as valleytronic devices and valley–spin qubits8. 2D TMDs also provide a platform for novel quantum optoelectronic devices9,10,11 due to their large exciton binding energy12,13. However, controlled confinement and manipulation of electronic and excitonic excitations in TMD nanostructures have been technically challenging due to the prevailing disorder in the material, preventing accurate experimental control of local confinement and tunnel couplings14,15,16. Here we demonstrate a novel method for creating high-quality heterostructures composed of atomically thin materials that allows for efficient electrical control of excitations. Specifically, we demonstrate quantum transport in the gate-defined, quantum-confined region, observing spin–valley locked quantized conductance in quantum point contacts. We also realize gate-controlled Coulomb blockade associated with confinement of electrons and demonstrate electrical control over charged excitons with tunable local confinement potentials and tunnel couplings. Our work provides a basis for novel quantum opto-electronic devices based on manipulation of charged carriers and excitons.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Semiconducting van der Waals heterostructure with mesoscopic backgates.
Fig. 2: Conductance quantization via quantum point contact.
Fig. 3: Quantum confinement of charge carriers.
Fig. 4: Optoelectronic transport in gate-defined MoSe2 nanostructures.
Fig. 5: Gate-defined confinement of charged excitons.

Similar content being viewed by others

References

  1. Loss, D. & DiVincenzo, D. P. Quantum computation with quantum dots. Phys. Rev. A 57, 120 (1998).

    Article  Google Scholar 

  2. Petta, J. R. et al. Coherent manipulation of coupled electron spins in semiconductor quantum dots. Science 309, 2180–2184 (2005).

    Article  Google Scholar 

  3. Hanson, R., Kouwenhoven, L. P., Petta, J. R., Tarucha, S. & Vandersypen, L. M. K. Spin in few-electron quantum dots. Rev. Mod. Phys. 79, 1217 (2007).

    Article  Google Scholar 

  4. Jariwala, D., Sangwan, V. K., Lauhon, L. J., Marks, T. J. & Hersam, M. C. Emerging device applications for semiconducting two-dimensional transition metal dichalcogenides. ACS Nano 8, 1102–1120 (2014).

    Article  Google Scholar 

  5. Jariwala, D., Marks, T. J. & Hersam, M. C. Mixed-dimensional van der Waals heterostructures. Nat. Mater. 16, 170–181 (2017).

    Article  Google Scholar 

  6. Xiao, D., Liu, G., Feng, W., Xu, X. & Yao, W. Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides. Phys. Rev. Lett. 108, 196802 (2012).

    Article  Google Scholar 

  7. Xu, X., Yao, W., Xiao, D. & Heinz, T. F. Spin and pseudospins in layered transition metal dichalcogenides. Nat. Phys. 10, 343–350 (2014).

    Article  Google Scholar 

  8. Kormányos, A., Zólyomi, V., Drummond, N. D. & Burkard, G. Spin-orbit coupling, quantum dots, and qubits in monolayer transition metal dichalcogenides. Phys. Rev. X 4, 011034 (2014).

    Google Scholar 

  9. Rivera, P. et al. Valley-polarized exciton dynamics in a 2D semiconductor heterostructure. Science 351, 6274 (2016).

    Article  Google Scholar 

  10. Wang, Q. H., Kalantar-Zadeh, K., Kis, A., Coleman, J. N. & Strano, M. S. Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. Nat. Nanotech. 7, 699–712 (2012).

    Article  Google Scholar 

  11. Ma, K. F. & Shan, J. Photonics and optoelectronics of 2D semiconductor transition metal dichalcogenides. Nat. Photon. 10, 216–226 (2016).

    Article  Google Scholar 

  12. Moody, G. et al. Electronic enhancement of the exciton coherence time in charged quantum dots. Phys. Rev. Lett. 116, 037402 (2016).

    Article  Google Scholar 

  13. Pioda, A. et al. Single-shot detection of electrons generated by individual photons in a tunable lateral quantum dot. Phys. Rev. Lett. 106, 146804 (2011).

  14. Lee, K., Kulkarnia, G. & Zhong, Z. Coulomb blockade in monolayer MoS2 single electron transistor. Nanoscale 8, 7755–7760 (2016).

    Article  Google Scholar 

  15. Song, X.-X. et al. A gate defined quantum dot on the two-dimensional transition metal dichalcogenide semiconductor WSe2. Nanoscale 7, 16867–16873 (2015).

    Article  Google Scholar 

  16. Song, X.-X. et al. Temperature dependence of Coulomb oscillations in a few-layer two-dimensional WS2 quantum dot. Sci. Rep. 5, 16113 (2015).

    Google Scholar 

  17. Mak, K. F., Lee, C., Hone, J., Shan, J. & Heinz, T. F. Atomically thin MoS2: a new direct-gap semiconductor. Phys. Rev. Lett. 105, 136805 (2010).

    Article  Google Scholar 

  18. Radisavljevic, B., Radenovic, A., Brivio, J., Giacometti, V. & Kis, A. Single-layer MoS2 transistors. Nat. Nanotech. 6, 147–150 (2011).

    Google Scholar 

  19. Wu, Z. et al. Even–odd layer-dependent magnetotransport of high-mobility Q-valley electrons in transition metal disulfides. Nat. Commun. 7, 12955 (2016).

    Google Scholar 

  20. Laroche, D., Gervais, G., Lilly, M. P. & Reno, J. L. 1D–1D Coulomb drag signature of a Luttinger liquid. Science 343, 6171 (2014).

    Article  Google Scholar 

  21. Bischoff, D. et al. Measurement back-action in stacked graphene quantum dots. Nano Lett. 15, 6003–6008 (2015).

    Article  Google Scholar 

  22. Payette, C. et al. Single charge sensing and transport in double quantum dots fabricated from commercially grown Si/SiGe heterostructures. Appl. Phys. Lett. 100, 043508 (2012).

    Article  Google Scholar 

  23. Wang, M. et al. Quantum dot behavior in bilayer graphene nanoribbons. ACS Nano 5, 8769–8773 (2011).

    Article  Google Scholar 

  24. Cui, X. et al. Multi-terminal transport measurements of MoS2 using a van der Waals heterostructure device platform. Nat. Nanotech. 10, 534–540 (2015).

    Google Scholar 

  25. Kim, K. et al. Shubnikov–de Haas oscillations of high-mobility holes in monolayer and bilayer WSe2: Landau level degeneracy, effective mass, and negative compressibility. Phys. Rev. Lett. 116, 086601 (2016).

    Article  Google Scholar 

  26. Kayyalha, M., Maassen, J., Lundstrom, M., Shi, L. & Chen, Y. P. Gate-tunable and thickness-dependent electronic and thermoelectric transport in few-layer MoS2. J. Appl. Phys. 120, 134305 (2016).

    Article  Google Scholar 

  27. Wang, L. et al. One-dimensional electrical contact to a two-dimensional material. Science 342, 614–617 (2013).

    Google Scholar 

  28. van Wees, B. J. et al. Quantized conductance of point contacts in a two-dimensional electron gas. Phys. Rev. Lett. 60, 848 (1988).

    Article  Google Scholar 

  29. Wang, K., Payette, C., Dovzhenko, Y., Deelman, P. W. & Petta, J. R. Charge relaxation in a single-electron Si/SiGe double quantum dot. Phys. Rev. Lett. 111, 046801 (2013).

    Article  Google Scholar 

  30. Sidler, M. et al. Fermi polaron–polaritons in charge tunable atomically thin semiconductors. Nat. Phys. 13, 255–261 (2016).

    Article  Google Scholar 

  31. Scharf, B. et al. Probing many-body interactions in monolayer transition metal dichalcogenides. Preprint at https://arxiv.org/abs/1606.07101 (2016).

  32. Efemkin, D. K. & MacDonald, A. H. Many-body theory of trion absorption features in two-dimensional semiconductors. Phys. Rev. B 95, 035417 (2017).

    Article  Google Scholar 

  33. Umansky, V., de-Picciotto, R. & Heiblum, M. Extremely high-mobility two dimensional electron gas: evaluation of scattering mechanisms. Appl. Phys. Lett. 71, 683 (1997).

    Article  Google Scholar 

Download references

Acknowledgements

We thank J. Waissman and E. Lee for helpful discussions. The major experimental work was supported by AFOSR (grant FA9550-14-1-0268), DoD Vannevar Bush Faculty Fellowship (grant N00014-16-1-2825), and Samsung Electronics. K.W. acknowledges support from ARO MURI (W911NF-14-1-0247). P.K. acknowledges partial support from ONR MURI (grant N00014-15-1-2761) and the FAME Center. H.P. and M.D.L. acknowledge partial support from AFOSR MURI (FA9550-17-1-0002), NSF (PHY-1506284), and NSF CUA (PHY-1125846). K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan and JSPS KAKENHI grant numbers JP26248061, JP15K21722 and JP25106006. A portion of this work was performed at the National High Magnetic Field Laboratory, which is supported by National Science Foundation Cooperative Agreement No. DMR-1157490 and the State of Florida. Nanofabrication was performed at the Center for Nanoscale Systems at Harvard, supported in part by an NSF NNIN award ECS-00335765.

Author information

Authors and Affiliations

Authors

Contributions

K.W. performed the experiments and analysed the data. K.D.G., L.J., A.S., A.H., Y.Z. and G.S. performed optical measurements, K.W. and L.J. fabricated devices, K.W. and P.K. conceived the electron transport experiment. K.W., K.D.G., M.L., H.P. and P.K. conceived the optoelectronic experiment. K.W. and T.T. provided hBN crystals.

Corresponding author

Correspondence to Philip Kim.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figs. 1–3 and Supplementary References.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wang, K., De Greve, K., Jauregui, L.A. et al. Electrical control of charged carriers and excitons in atomically thin materials. Nature Nanotech 13, 128–132 (2018). https://doi.org/10.1038/s41565-017-0030-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41565-017-0030-x

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing