Interlayer valley excitons in heterobilayers of transition metal dichalcogenides

Abstract

Stacking different two-dimensional crystals into van der Waals heterostructures provides an exciting approach to designing quantum materials that can harness and extend the already fascinating properties of the constituents. Heterobilayers of transition metal dichalcogenides are particularly attractive for low-dimensional semiconductor optics because they host interlayer excitons—with electrons and holes localized in different layers—which inherit valley-contrasting physics from the monolayers and thereby possess various novel and appealing properties compared to other solid-state nanostructures. This Review presents the contemporary experimental and theoretical understanding of these interlayer excitons. We discuss their unique optical properties arising from the underlying valley physics, the strong many-body interactions and electrical control resulting from the electric dipole moment, and the unique effects of a moiré superlattice on the interlayer exciton potential landscape and optical properties.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Fig. 1: Heterobilayers of monolayer transition metal dichalcogenides.
Fig. 2: Interlayer excitons and charge transfer in TMD heterobilayers.
Fig. 3: Interlayer valley exciton properties.
Fig. 4: Exciton–exciton interactions.
Fig. 5: Moiré landscape for interlayer excitons.

References

  1. 1.

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

  2. 2.

    Sun, D., Lai, J. W., Ma, J. C., Wang, Q. S. & Liu, J. Review of ultrafast spectroscopy studies of valley carrier dynamics in two-dimensional semiconducting transition metal dichalcogenides. Chin. Phys. B 26, 037801 (2017).

  3. 3.

    Yu, H., Cui, X., Xu, X. & Yao, W. Valley excitons in two-dimensional semiconductors. Natl. Sci. Rev. 2, 57–70 (2015).

  4. 4.

    Schaibley, J. R. et al. Valleytronics in 2D materials. Nat. Rev. Mater. 1, 16055 (2016).

  5. 5.

    Xiao, D., Liu, G. B., 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).

  6. 6.

    Mak, K. F., He, K., Shan, J. & Heinz, T. F. Control of valley polarization in monolayer MoS2 by optical helicity. Nat. Nanotech. 7, 494–498 (2012).

  7. 7.

    Zeng, H., Dai, J., Yao, W., Xiao, D. & Cui, X. Valley polarization in MoS2 monolayers by optical pumping. Nat. Nanotech. 7, 490–493 (2012).

  8. 8.

    Cao, T. et al. Valley-selective circular dichroism of monolayer molybdenum disulphide. Nat. Commun. 3, 887 (2012).

  9. 9.

    Jones, A. M. et al. Optical generation of excitonic valley coherence in monolayer WSe2. Nat. Nanotech. 8, 634–638 (2013).

  10. 10.

    Wang, G. et al. Control of exciton valley coherence in transition metal dichalcogenide monolayers. Phys. Rev. Lett. 117, 187401 (2016).

  11. 11.

    Ye, Z., Sun, D. & Heinz, T. F. Optical manipulation of valley pseudospin. Nat. Phys. 13, 26–29 (2016).

  12. 12.

    Hao, K. et al. Direct measurement of exciton valley coherence in monolayer WSe2. Nat. Phys. 12, 677–682 (2016).

  13. 13.

    Schmidt, R. et al. Magnetic-field-induced rotation of polarized light emission from monolayer WS2. Phys. Rev. Lett. 117, 077402 (2016).

  14. 14.

    Yu, T. & Wu, M. W. Valley depolarization due to intervalley and intravalley electron–hole exchange interactions in monolayer MoS2. Phys. Rev. B 89, 205303 (2014).

  15. 15.

    Maialle, M. Z., de Andrada e Silva, E. A. & Sham, L. J. Exciton spin dynamics in quantum wells. Phys. Rev. B 47, 15776–15788 (1993).

  16. 16.

    Bayer, M. et al. Fine structure of neutral and charged excitons in self-assembled In(Ga)As/(Al)GaAs quantum dots. Phys. Rev. B 65, 195315 (2002).

  17. 17.

    Yu, H., Liu, G. B., Gong, P., Xu, X. & Yao, W. Dirac cones and Dirac saddle points of bright excitons in monolayer transition metal dichalcogenides. Nat. Commun. 5, 3876 (2014).

  18. 18.

    Glazov, M. M. et al. Exciton fine structure and spin decoherence in monolayers of transition metal dichalcogenides. Phys. Rev. B 89, 201302(R) (2014).

  19. 19.

    Geim, A. K. & Grigorieva, I. V. Van der Waals heterostructures. Nature 499, 419–425 (2013).

  20. 20.

    Novoselov, K. S., Mishchenko, A., Carvalho, A. & Castro Neto, A. H. 2D materials and van der Waals heterostructures. Science 353, aac9439 (2016).

  21. 21.

    Liu, Y. et al. Van der Waals heterostructures and devices. Nat. Rev. Mater. 1, 16042 (2016).

  22. 22.

    Andres, C.-G. et al. Deterministic transfer of two-dimensional materials by all-dry viscoelastic stamping. 2D Mater. 1, 011002 (2014).

  23. 23.

    Zomer, P. J., Guimarães, M. H. D., Brant, J. C., Tombros, N. & van Wees, B. J. Fast pick up technique for high quality heterostructures of bilayer graphene and hexagonal boron nitride. Appl. Phys. Lett. 105, 013101 (2014).

  24. 24.

    Dean, C. R. et al. Boron nitride substrates for high-quality graphene electronics. Nat. Nanotech. 5, 722–726 (2010).

  25. 25.

    Lee, C. H. et al. Atomically thin p–n junctions with van der Waals heterointerfaces. Nat. Nanotech. 9, 676–681 (2014).

  26. 26.

    Zhang, C. et al. Interlayer couplings, moiré patterns, and 2D electronic superlattices in MoS2/WSe2 hetero-bilayers. Sci. Adv. 3, e1601459 (2017).

  27. 27.

    Heo, H. et al. Rotation-misfit-free heteroepitaxial stacking and stitching growth of hexagonal transition-metal dichalcogenide monolayers by nucleation kinetics controls. Adv. Mater. 27, 3803–3810 (2015).

  28. 28.

    Gong, Y. et al. Vertical and in-plane heterostructures from WS2/MoS2 monolayers. Nat. Mater. 13, 1135–1142 (2014).

  29. 29.

    Yu, Y. et al. Equally efficient interlayer exciton relaxation and improved absorption in epitaxial and nonepitaxial MoS2/WS2 heterostructures. Nano Lett. 15, 486–491 (2015).

  30. 30.

    Duan, X., Wang, C., Pan, A., Yu, R. & Duan, X. Two-dimensional transition metal dichalcogenides as atomically thin semiconductors: opportunities and challenges. Chem. Soc. Rev. 44, 8859–8876 (2015).

  31. 31.

    Cheng, R. et al. Electroluminescence and photocurrent generation from atomically sharp WSe2/MoS2 heterojunction p–n diodes. Nano Lett. 14, 5590–5597 (2014).

  32. 32.

    Lin, Y. C. et al. Atomically thin resonant tunnel diodes built from synthetic van der Waals heterostructures. Nat. Commun. 6, 7311 (2015).

  33. 33.

    Fang, H. et al. Strong interlayer coupling in van der Waals heterostructures built from single-layer chalcogenides. Proc. Natl. Acad. Sci. USA 111, 6198–6202 (2014).

  34. 34.

    Miller, D. A. B. et al. Band-edge electroabsorption in quantum well structures — the quantum-confined Stark-effect. Phys. Rev. Lett. 53, 2173–2176 (1984).

  35. 35.

    Charbonneau, S., Thewalt, M. L., Koteles, E. S. & Elman, B. Transformation of spatially direct to spatially indirect excitons in coupled double quantum wells. Phys. Rev. B 38, 6287–6290 (1988).

  36. 36.

    Chen, Y. J., Koteles, E. S., Elman, B. S. & Armiento, C. A. Effect of electric fields on excitons in a coupled double-quantum-well structure. Phys. Rev. B 36, 4562–4565 (1987).

  37. 37.

    Combescot, M., Combescot, R. & Dubin, F. Bose–Einstein condensation and indirect excitons: a review. Rep. Progr. Phys. 80, 066501 (2017).

  38. 38.

    Butov, L. V. Condensation and pattern formation in cold exciton gases in coupled quantum wells. J. Phys. Condens. Matter 16, R1577–R1613 (2004).

  39. 39.

    Butov, L. V. Cold exciton gases in coupled quantum well structures. J. Phys. Condens. Matter 19, 295202 (2007).

  40. 40.

    Rapaport, R. & Chen, G. Experimental methods and analysis of cold and dense dipolar exciton fluids. J. Phys. Condens. Matter 19, 295207 (2007).

  41. 41.

    Golub, J. E., Kash, K., Harbison, J. P. & Florez, L. T. Long-lived spatially indirect excitons in coupled GaAs/AlxGa1–xAs quantum wells. Phys. Rev. B 41, 8564–8567 (1990).

  42. 42.

    High, A. A., Novitskaya, E. E., Butov, L. V., Hanson, M. & Gossard, A. C. Control of exciton fluxes in an excitonic integrated circuit. Science 321, 229–231 (2008).

  43. 43.

    Fogler, M. M., Butov, L. V. & Novoselov, K. S. High-temperature superfluidity with indirect excitons in van der Waals heterostructures. Nat. Commun. 5, 4555 (2014).

  44. 44.

    Rivera, P. et al. Observation of long-lived interlayer excitons in monolayer MoSe2–WSe2 heterostructures. Nat. Commun. 6, 6242 (2015).

  45. 45.

    Rivera, P. et al. Valley-polarized exciton dynamics in a 2D semiconductor heterostructure. Science 351, 688–691 (2016).

  46. 46.

    Liu, G. B., Xiao, D., Yao, Y., Xu, X. & Yao, W. Electronic structures and theoretical modelling of two-dimensional group-VIB transition metal dichalcogenides. Chem. Soc. Rev. 44, 2643–2663 (2015).

  47. 47.

    Ozcelik, V. O., Azadani, J. G., Yang, C., Koester, S. J. & Low, T. Band alignment of two-dimensional semiconductors for designing heterostructures with momentum space matching. Phys. Rev. B 94, 035125 (2016).

  48. 48.

    Wilson, N. R. et al. Determination of band offsets, hybridization, and exciton binding in 2D semiconductor heterostructures. Sci. Adv. 3, e1601832 (2017).

  49. 49.

    Chiu, M. H. et al. Determination of band alignment in the single-layer MoS2/WSe2 heterojunction. Nat. Commun. 6, 7666 (2015).

  50. 50.

    Hill, H. M., Rigosi, A. F., Rim, K. T., Flynn, G. W. & Heinz, T. F. Band alignment in MoS2/WS2 transition metal dichalcogenide heterostructures probed by scanning tunneling microscopy and spectroscopy. Nano Lett. 16, 4831–4837 (2016).

  51. 51.

    Wang, Y., Wang, Z., Yao, W., Liu, G. B. & Yu, H. Y. Interlayer coupling in commensurate and incommensurate bilayer structures of transition-metal dichalcogenides. Phys. Rev. B 95, 115429 (2017).

  52. 52.

    Komsa, H. P. & Krasheninnikov, A. V. Electronic structures and optical properties of realistic transition metal dichalcogenide heterostructures from first principles. Phys. Rev. B 88, 085318 (2013).

  53. 53.

    Heo, H. et al. Interlayer orientation-dependent light absorption and emission in monolayer semiconductor stacks. Nat. Commun. 6, 7372 (2015).

  54. 54.

    Kośmider, K. & Fernández-Rossier, J. Electronic properties of the MoS2–WS2 heterojunction. Phys. Rev. B 87, 075451 (2013).

  55. 55.

    Terrones, H., Lopez-Urias, F. & Terrones, M. Novel hetero-layered materials with tunable direct band gaps by sandwiching different metal disulfides and diselenides. Sci. Rep. 3, 1549 (2013).

  56. 56.

    Bernardi, M., Palummo, M. & Grossman, J. C. Extraordinary sunlight absorption and one nanometer thick photovoltaics using two-dimensional monolayer materials. Nano Lett. 13, 3664–3670 (2013).

  57. 57.

    Amin, B., Singh, N. & Schwingenschlogl, U. Heterostructures of transition metal dichalcogenides. Phys. Rev. B 92, 075439 (2015).

  58. 58.

    Kang, J., Li, J., Li, S. S., Xia, J. B. & Wang, L. W. Electronic structural moiré pattern effects on MoS2/MoSe2 2D heterostructures. Nano Lett. 13, 5485–5490 (2013).

  59. 59.

    Tongay, S. et al. Tuning interlayer coupling in large-area heterostructures with CVD-grown MoS2 and WS2 monolayers. Nano Lett. 14, 3185–3190 (2014).

  60. 60.

    Liu, K. et al. Evolution of interlayer coupling in twisted molybdenum disulfide bilayers. Nat. Commun. 5, 4966 (2014).

  61. 61.

    van der Zande, A. M. et al. Tailoring the electronic structure in bilayer molybdenum disulfide via interlayer twist. Nano Lett. 14, 3869–3875 (2014).

  62. 62.

    Ceballos, F., Bellus, M. Z., Chiu, H. Y. & Zhao, H. Ultrafast charge separation and indirect exciton formation in a MoS2–MoSe2 van der Waals heterostructure. ACS Nano 8, 12717–12724 (2014).

  63. 63.

    Hong, X. et al. Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures. Nat. Nanotech. 9, 682–686 (2014).

  64. 64.

    Furchi, M. M., Pospischil, A., Libisch, F., Burgdorfer, J. & Mueller, T. Photovoltaic effect in an electrically tunable van der Waals heterojunction. Nano Lett. 14, 4785–4791 (2014).

  65. 65.

    Chiu, M. H. et al. Spectroscopic signatures for interlayer coupling in MoS2–WSe2 van der Waals stacking. ACS Nano 8, 9649–9656 (2014).

  66. 66.

    Rigosi, A. F., Hill, H. M., Li, Y., Chernikov, A. & Heinz, T. F. Probing interlayer interactions in transition metal dichalcogenide heterostructures by optical spectroscopy: MoS2/WS2 and MoSe2/WSe2. Nano Lett. 15, 5033–5038 (2015).

  67. 67.

    Zhu, H. et al. Interfacial charge transfer circumventing momentum mismatch at two-dimensional van der Waals heterojunctions. Nano Lett. 17, 3591–3598 (2017).

  68. 68.

    Chen, H. et al. Ultrafast formation of interlayer hot excitons in atomically thin MoS2/WS2 heterostructures. Nat. Commun. 7, 12512 (2016).

  69. 69.

    Peng, B. et al. Ultrafast charge transfer in MoS2/WSe2 p–n heterojunction. 2D Mater. 3, 025020 (2016).

  70. 70.

    Schaibley, J. R. et al. Directional interlayer spin-valley transfer in two-dimensional heterostructures. Nat. Commun. 7, 13747 (2016).

  71. 71.

    Surrente, A. et al. Defect healing and charge transfer-mediated valley polarization in MoS2/MoSe2/MoS2 trilayer van der Waals heterostructures. Nano Lett. 17, 4130–4136 (2017).

  72. 72.

    Wang, K. et al. Interlayer coupling in twisted WSe2/WS2 bilayer heterostructures revealed by optical spectroscopy. ACS Nano 10, 6612–6622 (2016).

  73. 73.

    Yu, H., Wang, Y., Tong, Q., Xu, X. & Yao, W. Anomalous light cones and valley optical selection rules of interlayer excitons in twisted heterobilayers. Phys. Rev. Lett. 115, 187002 (2015).

  74. 74.

    Yu, H., Liu, G. B., Tang, J., Xu, X. & Yao, W. Moiré excitons: from programmable quantum emitter arrays to spin–orbit-coupled artificial lattices. Sci. Adv. 3, e1701696 (2017).

  75. 75.

    Miller, B. et al. Long-lived direct and indirect interlayer excitons in van der Waals heterostructures. Nano Lett. 17, 5229–5237 (2017).

  76. 76.

    Jiang, C. et al. Microsecond dark-exciton valley polarization memory in 2D heterostructures. Nat. Commun. 9, 753 (2017).

  77. 77.

    FengCheng, Wu,T. L. & MacDonald, A. H. Theory of optical absorption by interlayer excitons in transition metal dichalcogenide heterobilayers. Phys. Rev. B 97, 035306 (2017).

  78. 78.

    Nayak, P. K. et al. Probing evolution of twist-angle-dependent interlayer excitons in MoSe2/WSe2 van der Waals heterostructures. ACS Nano 11, 4041–4050 (2017).

  79. 79.

    Alexeev, E. M. et al. Imaging of interlayer coupling in van der Waals heterostructures using a bright-field optical microscope. Nano Lett. 17, 5342–5349 (2017).

  80. 80.

    Lui, C. H. et al. Observation of interlayer phonon modes in van der Waals heterostructures. Phys. Rev. B 91, 165403 (2015).

  81. 81.

    Nagler, P. et al. Interlayer exciton dynamics in a dichalcogenide monolayer heterostructure. 2D Mater. 4, 025112 (2017).

  82. 82.

    Luong, D. H. et al. Tunneling photocurrent assisted by interlayer excitons in staggered van der Waals hetero-bilayers. Adv. Mater. 29, 1701512 (2017).

  83. 83.

    Ceballos, F., Bellus, M. Z., Chiu, H. Y. & Zhao, H. Probing charge transfer excitons in a MoSe2–WS2 van der Waals heterostructure. Nanoscale 7, 17523–17528 (2015).

  84. 84.

    Zhang, K. et al. Interlayer transition and infrared photodetection in atomically thin type-II MoTe2/MoS2 van der Waals heterostructures. ACS Nano 10, 3852–3858 (2016).

  85. 85.

    Mouri, S. et al. Thermal dissociation of inter-layer excitons in MoS2/MoSe2 hetero-bilayers. Nanoscale 9, 6674–6679 (2017).

  86. 86.

    Bellus, M. Z., Ceballos, F., Chiu, H. Y. & Zhao, H. Tightly bound trions in transition metal dichalcogenide heterostructures. ACS Nano 9, 6459–6464 (2015).

  87. 87.

    Nagler, P. et al. Giant magnetic splitting inducing near-unity valley polarization in van der Waals heterostructures. Nat. Commun. 8, 1551 (2017).

  88. 88.

    Kim, M. S. et al. Simultaneous hosting of positive and negative trions and the enhanced direct band emission in MoSe2/MoS2 heterostacked multilayers. ACS Nano 10, 6211–6219 (2016).

  89. 89.

    Kumar, N. et al. Second harmonic microscopy of monolayer MoS2. Phys. Rev. B 87, 161403(R) (2013).

  90. 90.

    Li, Y. et al. Probing symmetry properties of few-layer MoS2 and h-BN by optical second-harmonic generation. Nano Lett. 13, 3329–3333 (2013).

  91. 91.

    Malard, L. M., Alencar, T. V., Barboza, A. P. M., Mak, K. F. & de Paula, A. M. Observation of intense second harmonic generation from MoS2 atomic crystals. Phys. Rev. B 87, 201401(R) (2013).

  92. 92.

    Hsu, W. T. et al. Second harmonic generation from artificially stacked transition metal dichalcogenide twisted bilayers. ACS Nano 8, 2951–2958 (2014).

  93. 93.

    Bollinger, M. V. et al. One-dimensional metallic edge states in MoS2. Phys. Rev. Lett. 87, 196803 (2001).

  94. 94.

    Wang, Z. et al. Mixed low-dimensional nanomaterial: 2D ultranarrow MoS2 inorganic nanoribbons encapsulated in quasi-1D carbon nanotubes. J. Am. Chem. Soc. 132, 13840–13847 (2010).

  95. 95.

    Chu, R.-L. et al. Spin–orbit-coupled quantum wires and Majorana fermions on zigzag edges of monolayer transition-metal dichalcogenides. Phys. Rev. B 89, 155317 (2014).

  96. 96.

    Ceballos, F., Bellus, M. Z., Chiu, H.-Y. & Zhao, H. Ultrafast charge separation and indirect exciton formation in a MoS2–MoSe2 van der Waals heterostructure. ACS Nano 8, 12717–12724 (2014).

  97. 97.

    Zhu, X. et al. Charge transfer excitons at van der Waals interfaces. J. Am. Chem. Soc. 137, 8313–8320 (2015).

  98. 98.

    Baranowski, M. et al. Probing the interlayer exciton physics in a MoS2/MoSe2/MoS2 van der Waals heterostructure. Nano Lett. 17, 6360–6365 (2017).

  99. 99.

    Ross, J. S. et al. Interlayer exciton optoelectronics in a 2D heterostructure p–n junction. Nano Lett. 17, 638–643 (2017).

  100. 100.

    Forg, M. et al. Cavity-control of bright and dark interlayer excitons in van der Waals heterostructures. Preprint at https://arxiv.org/abs/1710.00990 (2017).

  101. 101.

    Kim, J. et al. Observation of ultralong valley lifetime in WSe2/MoS2 heterostructures. Sci. Adv. 3, e1700518 (2017).

  102. 102.

    Gao, S., Yang, L. & Spataru, C. D. Interlayer coupling and gate-tunable excitons in transition metal dichalcogenide heterostructures. Nano Lett. 17, 7809–7813 (2017).

  103. 103.

    Wang, Z., Chiu, Y. H., Honz, K., Mak, K. F. & Shan, J. Electrical tuning of interlayer exciton gases in WSe2 bilayers. Nano Lett. 18, 137–143 (2017).

  104. 104.

    Calman, E. V. et al. Control of excitons in multi-layer van der Waals heterostructures. Appl. Phys. Lett. 108, 101901 (2016).

  105. 105.

    Latini, S., Winther, K. T., Olsen, T. & Thygesen, K. S. Interlayer excitons and band alignment in MoS2/hBN/WSe2 van der Waals heterostructures. Nano Lett. 17, 938–945 (2017).

  106. 106.

    He, Y. et al. Strain-induced electronic structure changes in stacked van der Waals heterostructures. Nano Lett. 16, 3314–3320 (2016).

  107. 107.

    Butov, L. V., Lai, C. W., Ivanov, A. L., Gossard, A. C. & Chemla, D. S. Towards Bose–Einstein condensation of excitons in potential traps. Nature 417, 47–52 (2002).

  108. 108.

    Debnath, B., Barlas, Y., Wickramaratne, D., Neupane, M. R. & Lake, R. K. Exciton condensate in bilayer transition metal dichalcogenides: strong coupling regime. Phys. Rev. B 96, 174504 (2017).

  109. 109.

    Cohen, K., Khodas, M., Laikhtman, B., Santos, P. V. & Rapaport, R. Vertically coupled dipolar exciton molecules. Phys. Rev. B 93, 235310 (2016).

  110. 110.

    Liu, C. S., Xu, T. F., Liu, Y. H. & Jing, X. L. Theory of indirect exciton photoluminescence in elevated quantum trap. Phys. E 63, 193–198 (2014).

  111. 111.

    Schinner, G. J. et al. Confinement and interaction of single indirect excitons in a voltage-controlled trap formed inside double InGaAs quantum Wells. Phys. Rev. Lett. 110, 127403 (2013).

  112. 112.

    Dietl, S. et al. Collective electronic excitation in a trapped ensemble of photogenerated dipolar excitons and free holes revealed by inelastic light scattering. Phys. Rev. B 95, 235310 (2017).

  113. 113.

    Wu, F., Lovorn, T. & MacDonald, A. H. Topological exciton bands in moiré heterojunctions. Phys. Rev. Lett. 118, 147401 (2017).

  114. 114.

    Wu, M., Qian, X. & Li, J. Tunable exciton funnel using moiré superlattice in twisted van der Waals bilayer. Nano Lett. 14, 5350–5357 (2014).

  115. 115.

    Tong, Q. et al. Topological mosaics in moiré superlattices of van der Waals heterobilayers. Nat. Phys. 13, 356–362 (2016).

  116. 116.

    Cosma, D. A., Wallbank, J. R., Cheianov, V. & Fal'ko, V. I. Moiré pattern as a magnifying glass for strain and dislocations in van der Waals heterostructures. Faraday Discuss. 173, 137–143 (2014).

  117. 117.

    Polini, M., Guinea, F., Lewenstein, M., Manoharan, H. C. & Pellegrini, V. Artificial honeycomb lattices for electrons, atoms and photons. Nat. Nanotech. 8, 625–633 (2013).

  118. 118.

    Li, Y. M. et al. Light-induced exciton spin Hall effect in van der Waals heterostructures. Phys. Rev. Lett. 115, 166804 (2015).

  119. 119.

    Seamons, J. A., Morath, C. P., Reno, J. L. & Lilly, M. P. Coulomb drag in the exciton regime in electron–hole bilayers. Phys. Rev. Lett. 102, 026804 (2009).

  120. 120.

    Lamas-Linares, A., Howell, J. C. & Bouwmeester, D. Stimulated emission of polarization-entangled photons. Nature 412, 887–890 (2001).

  121. 121.

    Perczel, J. et al. Topological quantum optics in two-dimensional atomic arrays. Phys. Rev. Lett. 119, 023603 (2017).

  122. 122.

    Park, K.-D., Jiang, T., Clark, G., Xu, X. & Raschke, M. B. Radiative control of dark excitons at room temperature by nano-optical antenna-tip induced Purcell effect. Nat. Nanotech. 13, 59–64 (2017).

  123. 123.

    Liu, X. et al. Strong light–matter coupling in two-dimensional atomic crystals. Nat. Photon. 9, 30–34 (2014).

  124. 124.

    Sun, Z. et al. Optical control of room-temperature valley polaritons. Nat. Photon. 11, 491–496 (2017).

  125. 125.

    Dufferwiel, S. et al. Valley-addressable polaritons in atomically thin semiconductors. Nat. Photon. 11, 497–501 (2017).

  126. 126.

    Jones, A. M. et al. Spin-layer locking effects in optical orientation of exciton spin in bilayer WSe2. Nat. Phys. 10, 130–134 (2014).

Download references

Acknowledgements

Work at the University of Washington was supported by the Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division (DE-SC0018171). Work at HKU is supported by the Croucher Foundation (Croucher Innovation Award), UGC (AoE/P-04/08) and RGC (HKU17312916) of HKSAR. X.X. acknowledges the support from the State of Washington funded Clean Energy Institute and from the Boeing Distinguished Professorship in Physics.

Author information

Correspondence to Wang Yao or Xiaodong Xu.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

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

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Rivera, P., Yu, H., Seyler, K.L. et al. Interlayer valley excitons in heterobilayers of transition metal dichalcogenides. Nature Nanotech 13, 1004–1015 (2018) doi:10.1038/s41565-018-0193-0

Download citation

Further reading