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Femtosecond photo-switching of interface polaritons in black phosphorus heterostructures


The possibility of hybridizing collective electronic motion with mid-infrared light to form surface polaritons has made van der Waals layered materials a versatile platform for extreme light confinement1,2,3,4,5 and tailored nanophotonics6,7,8. Graphene9,10 and its heterostructures11,12,13,14 have attracted particular attention because the absence of an energy gap allows plasmon polaritons to be tuned continuously. Here, we introduce black phosphorus15,16,17,18,19 as a promising new material in surface polaritonics that features key advantages for ultrafast switching. Unlike graphene, black phosphorus is a van der Waals bonded semiconductor, which enables high-contrast interband excitation of electron–hole pairs by ultrashort near-infrared pulses. Here, we design a SiO2/black phosphorus/SiO2 heterostructure in which the surface phonon modes of the SiO2 layers hybridize with surface plasmon modes in black phosphorus that can be activated by photo-induced interband excitation. Within the Reststrahlen band of SiO2, the hybrid interface polariton assumes surface-phonon-like properties, with a well-defined frequency and momentum and excellent coherence. During the lifetime of the photogenerated electron–hole plasma, coherent hybrid polariton waves can be launched by a broadband mid-infrared pulse coupled to the tip of a scattering-type scanning near-field optical microscopy set-up. The scattered radiation allows us to trace the new hybrid mode in time, energy and space. We find that the surface mode can be activated within 50 fs and disappears within 5 ps, as the electron–hole pairs in black phosphorus recombine. The excellent switching contrast and switching speed, the coherence properties and the constant wavelength of this transient mode make it a promising candidate for ultrafast nanophotonic devices.

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Figure 1: Overview of near-field microsopy on a switchable phonon–plasmon–polariton device.
Figure 2: Ultrafast near-field spectroscopy of a SiO2/BP/SiO2 heterostructure.
Figure 3: Hybrid phonon–plasmon polariton dispersion.
Figure 4: Switching and decay of a hybrid phonon–plasmon–polariton mode.


  1. Low, T. & Avouris, P. Graphene plasmonics for terahertz to mid-infrared applications. ACS Nano 8, 1086–1101 (2014).

    Article  CAS  Google Scholar 

  2. Fei, Z. et al. Gate-tuning of graphene plasmons revealed by infrared nano-imaging. Nature 487, 82–85 (2012).

    Article  CAS  Google Scholar 

  3. Chen, J. et al. Optical nano-imaging of gate-tunable graphene plasmons. Nature 487, 77–81 (2012).

    Article  CAS  Google Scholar 

  4. Fei, Z. et al. Infrared nanoscopy of Dirac plasmons at the graphene–SiO2 interface. Nano Lett. 11, 4701–4705 (2011).

    Article  CAS  Google Scholar 

  5. Dai, S. et al. Tunable phonon polaritons in atomically thin van der Waals crystals of boron nitride. Science 343, 1125–1129 (2014).

    Article  CAS  Google Scholar 

  6. Caldwell, J. D. et al. Atomic-scale photonic hybrids for mid-infrared and terahertz nanophotonics. Nat. Nanotech. 11, 9–15 (2016).

    Article  CAS  Google Scholar 

  7. Schuller, J. A. et al. Plasmonics for extreme light concentration and manipulation. Nat. Mater. 9, 193–204 (2010).

    Article  CAS  Google Scholar 

  8. Xia, F., Wang, H., Xiao, D., Dubey, M. & Ramasubramaniam, A. Two-dimensional material nanophotonics. Nat. Photon. 8, 899–907 (2014).

    Article  CAS  Google Scholar 

  9. Wagner, M. et al. Ultrafast and nanoscale plasmonic phenomena in exfoliated graphene revealed by infrared pump–probe nanoscopy. Nano Lett. 14, 894–900 (2014).

    Article  CAS  Google Scholar 

  10. Ni, G. X. et al. Ultrafast optical switching of infrared plasmon polaritons in high-mobility graphene. Nat. Photon. 10, 244–247 (2016).

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  12. Woessner, A. et al. Highly confined low-loss plasmons in graphene–boron nitride heterostructures. Nat. Mater. 14, 421–425 (2014).

    Article  Google Scholar 

  13. Brar, V. W. et al. Hybrid surface-phonon–plasmon polariton modes in graphene/monolayer h-BN heterostructures. Nano Lett. 14, 3876–3880 (2014).

    Article  CAS  Google Scholar 

  14. Dai, S. et al. Graphene on hexagonal boron nitride as a tunable hyperbolic metamaterial. Nat. Nanotech. 10, 682–686 (2015).

    Article  CAS  Google Scholar 

  15. Ling, X., Wang, H., Huang, S., Xia, F. & Dresselhaus, M. S. The renaissance of black phosphorus. Proc. Natl Acad. Sci. USA 112, 4523–4530 (2015).

    Article  CAS  Google Scholar 

  16. Qiao, J., Kong, X., Hu, Z.-X., Yang, F. & Ji, W. High-mobility transport anisotropy and linear dichroism in few-layer black phosphorus. Nat. Commun. 5, 4475 (2014).

    Article  CAS  Google Scholar 

  17. Li, L. et al. Black phosphorus field-effect transistors. Nat. Nanotech. 9, 372–377 (2014).

    Article  CAS  Google Scholar 

  18. Viti, L. et al. Black phosphorus terahertz photodetectors. Adv. Mater. 27, 5567–5572 (2015).

    Article  CAS  Google Scholar 

  19. Viti, L. et al. Efficient terahertz detection in black-phosphorus nano-transistors with selective and controllable plasma-wave, bolometric and thermoelectric response. Sci. Rep. 6, 20474 (2016).

    Article  CAS  Google Scholar 

  20. Castellanos-Gomez, A. et al. Isolation and characterization of few-layer black phosphorus. 2D Mater. 1, 025001 (2014).

    Article  Google Scholar 

  21. Gamage, S. et al. Nanoscopy of black phosphorus degradation. Adv. Mater. Interfaces 3, 1600121 (2016).

    Article  Google Scholar 

  22. Wood, J. D. et al. Effective passivation of exfoliated black phosphorus transistors against ambient degradation. Nano Lett. 14, 6964–6970 (2014).

    Article  CAS  Google Scholar 

  23. Doganov, R. A. et al. Transport properties of pristine few-layer black phosphorus by van der Waals passivation in an inert atmosphere. Nat. Commun. 6, 6647 (2015).

    Article  CAS  Google Scholar 

  24. Eisele, M. et al. Ultrafast multi-terahertz nano-spectroscopy with sub-cycle temporal resolution. Nat. Photon. 8, 841–845 (2014).

    Article  CAS  Google Scholar 

  25. Huber, M. A. et al. Ultrafast mid-infrared nanoscopy of strained vanadium dioxide nanobeams. Nano Lett. 16, 1421–1427 (2016).

    Article  CAS  Google Scholar 

  26. Fehrenbacher, M. et al. Plasmonic superlensing in doped GaAs. Nano Lett. 15, 1057–1061 (2015).

    Article  CAS  Google Scholar 

  27. Li, P. et al. Reversible optical switching of highly confined phonon–polaritons with an ultrathin phase-change material. Nat. Mater. 15, 870–875 (2016).

    Article  CAS  Google Scholar 

  28. Van der Valk, N. C. J. & Planken, P. C. M. Electro-optic detection of subwavelength terahertz spot sizes in the near field of a metal tip. Appl. Phys. Lett. 81, 1558–1560 (2002).

    Article  CAS  Google Scholar 

  29. Günter, G. et al. Sub-cycle switch-on of ultrastrong light–matter interaction. Nature 458, 178–181 (2009).

    Article  Google Scholar 

  30. Novoselov, K. S. et al. Two-dimensional atomic crystals. Proc. Natl Acad. Sci. USA 102, 10451–10453 (2005).

    Article  CAS  Google Scholar 

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The authors thank M. Furthmeier for technical assistance and A. Politano, S.I. Blanter, A. Chernikov, D. Peller, and M. Eisele for discussions. This work was supported by the European Research Council through ERC grant 305003 (QUANTUMsubCYCLE) and ERC grant 681379 (SPRINT), the Deutsche Forschungsgemeinschaft through Research Training Group GRK 1570, SFB 689 and research grants CO1492/1 and HU1598/3.

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M.A.H., M.S.V., T.L.C. and R.H. conceived the study. M.A.H., F.M., M.P., F.S., L.Z.K., T.L.C. and R.H. carried out the experiment and analysed the data. L.V. and M.S.V. designed, fabricated and characterized the heterostructures of black phosphorus and silicon dioxide. M.A.H., F.M., M.P., T.F. and J.F. performed simulations. M.A.H., F.M., M.S.V., T.L.C. and R.H. wrote the manuscript. All authors contributed to the discussions.

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Correspondence to Miriam S. Vitiello or Tyler L. Cocker.

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The authors declare no competing financial interests.

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Huber, M., Mooshammer, F., Plankl, M. et al. Femtosecond photo-switching of interface polaritons in black phosphorus heterostructures. Nature Nanotech 12, 207–211 (2017).

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