Manipulation of light-matter interaction is critical in modern physics, especially in the strong coupling regime, where the generated half-light, half-matter bosonic quasiparticles as polaritons are important for fundamental quantum science and applications of optoelectronics and nonlinear optics. Two-dimensional transition metal dichalcogenides (TMDs) are ideal platforms to investigate the strong coupling because of their huge exciton binding energy and large absorption coefficients. Further studies on strong exciton-plasmon coupling by combining TMDs with metallic nanostructures have generated broad interests in recent years. However, because of the huge plasmon radiative damping, the observation of strong coupling is significantly limited at room temperature. Here, we demonstrate that a large Rabi splitting (~300 meV) can be achieved at ambient conditions in the strong coupling regime by embedding Ag-WS2 heterostructure in an optical microcavity. The generated quasiparticle with part-plasmon, part-exciton and part-light is analyzed with Hopfield coefficients that are calculated by using three-coupled oscillator model. The resulted plasmon-exciton polaritonic hybrid states can efficiently enlarge the obtained Rabi splitting, which paves the way for the practical applications of polaritonic devices based on ultrathin materials.
Large Rabi splitting obtained in Ag-WS2 strong-coupling heterostructure with optical microcavity at room temperature
1. Torma P, Barnes W L. Strong coupling between surface Plasmon polaritons and emitters: a review. Rep Prog Phys 78, 013901 (2015).
2. Christopoulos S, Von H?gersthal G B H, Grundy A J D, Lagoudakis P G, Kavokin A V et al. Room-temperature polariton lasing in semiconductor microcavities. Phys Rev Lett 98, 126405 (2007).
3. Kasprzak J, Richard M, Kundermann S, Baas A, Jeambrun P et al. Bose–Einstein condensation of exciton polaritons. Nature 443, 409–414 (2006).
4. Deng H, Haug H, Yamamoto Y. Exciton-polariton Bose-Einstein condensation. Rev Mod Phys 82, 1489–1537 (2010).
5. Plumhof J D, St?ferle T, Mai L J, Scherf U, Mahrt R F. Room-temperature Bose–Einstein condensation of cavity exciton–polaritons in a polymer. Nat Mater 13, 247–252 (2014).
6. Hutchison J A, Schwartz T, Genet C, Devaux E, Ebbesen T W. Modifying chemical landscapes by coupling to vacuum fields. Angew Chem Int Edit 51, 1592–1596 (2012).
7. Galego J, Garcia-Vidal FJ, Feist J. Suppressing photo-chemical reactions with quantized light fields. Nat Commun 7, 13841 (2016).
8. Shi X, Ueno K, Oshikiri T, Sun Q, Sasaki K et al. Enhanced water splitting under modal strong coupling conditions. Nat Nanotechnol 13, 953–958 (2018).
9. Amo A, Liew T C H, Adrados C, Houdré R, Giacobino E et al. Exciton–polariton spin switches. Nat Photonics 4, 361–366 (2010).
10. Peter E, Senellart P, Martrou D, Lema?tre A, Hours J et al. Exciton-photon strong-coupling regime for a single quantum dot embedded in a microcavity. Phys Rev Lett 95, 067401 (2005).
11. Baumberg J J, Kavokin A V, Christopoulos S, Grundy A J D, Butté R et al. Spontaneous polarization buildup in a room-temperature polariton laser. Phys Rev Lett 101, 136409 (2008).
12. Li F, Orosz L, Kamoun O, Bouchoule S, Brimont C et al. From excitonic to photonic polariton condensate in a ZnO-based microcavity. Phys Rev Lett 110, 196406 (2013).
13. Kéna-Cohen S, Forrest S R. Room-temperature polariton lasing in an organic single-crystal microcavity. Nat Photonics 4, 371–375 (2010).
14. Agranovich V M, Litinskaia M, Lidzey D G. Cavity polaritons in microcavities containing disordered organic semiconductors. Phys Rev B 67, 085311 (2003).
15. 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).
16. Wang Q H, Kalantar-Zadeh K, Kis A, Coleman J N, Strano M S. Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. Nat Nanotechnol 7, 699–712 (2012).
17. Ramasubramaniam A. Large excitonic effects in monolayers of molybdenum and tungsten dichalcogenides. Phys Rev B 86, 115409 (2012).
18. Qiu D Y, da Jornada F H, Louie S G. Optical spectrum of MoS2: many-body effects and diversity of exciton states. Phys Rev Lett 111, 216805 (2013).
19. Liu X Z, Galfsky T, Sun Z, Xia F N, Lin E C et al. Strong light–matter coupling in two-dimensional atomic crystals. Nat Photonics 9, 30–34 (2015).
20. Sun Z, Gu J, Ghazaryan A, Shotan Z, Considine C R et al. Optical control of room-temperature valley polaritons. Nat Photonics 11, 491–496 (2017).
21. Chen Y J, Cain J D, Stanev T K, Dravid V P, Stern N P. Val-ley-polarized exciton–polaritons in a monolayer semi-conductor. Nat Photonics 11, 431–435 (2017).
22. Barnes W L, Dereux A, Ebbesen T W. Surface plasmon subwavelength optics. Nature 424, 824–830 (2003).
23. Vasa P, Wang W, Pomraenke R, Lammers M, Maiuri M et al. Real-time observation of ultrafast Rabi oscillations between excitons and plasmons in metal nanostructures with J-aggregates. Nat Photonics 7, 128–132 (2013).
24. Va?keva?inen A I, Moerland R J, Rekola H T, Eskelinen A P, Martikainen J P et al. Plasmonic surface lattice resonances at the strong coupling regime. Nano Lett 14, 1721–1727 (2014).
25. Shi L, Hakala T K, Rekola H T, Martikainen J P, Moerland R J et al. Spatial coherence properties of organic molecules coupled to plasmonic surface lattice resonances in the weak and strong coupling regimes. Phys Rev Lett 112, 153002 (2014).
26. Rodriguez S R K, Feist J, Verschuuren M A, Garcia Vidal F J, Gómez Rivas J. Thermalization and cooling of plas-mon-exciton polaritons: towards quantum condensation. Phys Rev Lett 111, 166802 (2013).
27. Ha?gglund C, Zeltzer G, Ruiz R, Wangperawong A, Roelofs K E et al. Strong coupling of plasmon and nanocavity modes for dual-band, near-perfect absorbers and ultrathin photovoltaics. ACS Photonics 3, 456–463 (2016).
28. Yang J H, Sun Q, Ueno K, Shi X, Oshikiri T et al. Manipulation of the dephasing time by strong coupling between localized and propagating surface Plasmon modes. Nat Commun 9, 4858 (2018).
29. Shi J W, Lin M H, Chen I T, Estakhri N M, Zhang X Q et al. Cascaded exciton energy transfer in a monolayer semiconductor lateral heterostructure assisted by surface Plasmon polariton. Nat Commun 8, 35 (2017).
30. Wang M S, Li W, Scarabelli L, Rajeeva B B, Terrones M et al. Plasmon–trion and Plasmon–exciton resonance energy transfer from a single plasmonic nanoparticle to monolayer MoS2. Nanoscale 9, 13947–13955 (2017).
31. Wang Z, Dong Z G, Gu Y H, Chang Y H, Zhang L et al. Giant photoluminescence enhancement in tungsten-diselenide-gold plasmonic hybrid structures. Nat Commun 7, 11283 (2016).
32. Sobhani A, Lauchner A, Najmaei S, Ayala-Orozco C, Wen F F et al. Enhancing the photocurrent and photoluminescence of single crystal monolayer MoS2 with resonant plasmonic nanoshells. Appl Phys Lett 104, 031112 (2014).
33. Butun S, Tongay S, Aydin K. Enhanced light emission from large-area monolayer MoS2 using plasmonic nanodisc arrays. Nano Lett 15, 2700–2704 (2015).
34. Gao W, Lee Y H, Jiang R B, Wang J F, Liu T X et al. Lo-calized and continuous tuning of monolayer MoS2 photoluminescence using a single shape‐controlled Ag nanoantenna. Adv Mater 28, 701–706 (2016).
35. Janisch C, Song H M, Zhou C J, Lin Z, Elías A L et al. MoS2 monolayers on nanocavities: enhancement in light–matter in-teraction. 2D Mater 3, 025017 (2016)
36. Hao Q, Pang J B, Zhang Y, Wang J W, Ma L B et al. Boosting the photoluminescence of monolayer MoS2 on high‐density nanodimer arrays with sub-10 nm gap. Adv Opt Mater 6, 1700984 (2018).
37. Sun J W, Hu H T, Zheng D, Zhang D X, Deng Q et al. Light-emitting plexciton: exploiting Plasmon–exciton inter-action in the intermediate coupling regime. ACS Nano 12, 10393–10402 (2018).
38. Lee B, Park J, Han G H, Ee H S, Naylor C H et al. Fano reso-nance and spectrally modified photoluminescence enhancement in monolayer MoS2 integrated with plasmonic nanoantenna array. Nano Lett 15, 3646–3653 (2015).
39. Li B W, Zu S, Zhou J D, Jiang Q, Du B W et al. Sin-gle-nanoparticle plasmonic electro-optic modulator based on MoS2 monolayers. ACS Nano 11, 9720–9727 (2017).
40. Wang M S, Krasnok A, Zhang T Y, Scarabelli L, Liu H et al. Tunable fano resonance and Plasmon-exciton coupling in single Au nanotriangles on monolayer WS2 at room tem-perature. Adv Mater 30, 1705779 (2018).
41. Chikkaraddy R, de Nijs B, Benz F, Barrow S J, Scherman O A et al. Single-molecule strong coupling at room temperature in plasmonic nanocavities. Nature 535, 127–130 (2016).
42. Wang S J, Li S L, Chervy T, Shalabney A, Azzini S et al. Coherent coupling of WS2 monolayers with metallic photonic nanostructures at room temperature. Nano Lett 16, 4368–4374 (2016).
43. Zheng D, Zhang S P, Deng Q, Kang M, Nordlander P et al. Manipulating coherent Plasmon-exciton interaction in a single silver nanorod on monolayer WSe2. Nano Lett 17, 3809–3814 (2017).
44. Wen J X, Wang H, Wang W L, Deng Z X, Zhuang C et al. Room-temperature strong light–matter interaction with active control in single plasmonic nanorod coupled with two-dimensional atomic crystals. Nano Lett 17, 4689–4697 (2017).
45. Lee B, Liu W J, Naylor C H, Park J, Malek S C et al. Electrical tuning of exciton-Plasmon polariton coupling in monolayer MoS2 integrated with plasmonic nanoantenna lattice. Nano Lett 17, 4541–4547 (2017).
46. Cuadra J, Baranov D G, Wers?ll M, Verre R, Antosiewicz T J et al. Observation of tunable charged exciton polaritons in hybrid monolayer WS2-plasmonic nanoantenna system. Nano Lett 18, 1777–1785 (2018).
47. Wurdack M, Lundt N, Klaas M, Baumann V, Kavokin A V et al. Observation of hybrid Tamm-Plasmon exciton- polaritons with GaAs quantum wells and a MoSe2 monolayer. Nat Commun 8, 259 (2017).
48. Chakraborty B, Gu J, Sun Z, Khatoniar M, Bushati R et al. Control of strong light–matter interaction in monolayer WS2 through electric field gating. Nano Lett 18, 6455–6460 (2018).
49. Schuller J A, Barnard E S, Cai W S, Jun Y C, White J S et al. Plasmonics for extreme light concentration and manipulation. Nat Mater 9, 193–204 (2010).
50. Chanda D, Shigeta K, Truong T, Lui E, Mihi A et al. Coupling of plasmonic and optical cavity modes in qua-si-three-dimensional plasmonic crystals. Nat Commun 2, 479 (2011).
51. Ameling R, Giessen H. Cavity plasmonics: large normal mode splitting of electric and magnetic particle plasmons induced by a photonic microcavity. Nano Lett 10, 4394–4398 (2010).
52. Hopfield J J. Theory of the contribution of excitons to the complex dielectric constant of crystals. Phys Rev 112, 1555–1567 (1958).
53. Li Y L, Chernikov A, Zhang X, Rigosi A, Hill H M et al. Meas-urement of the optical dielectric function of monolayer transi-tion-metal dichalcogenides: MoS2, MoSe2, WS2, and WSe2. Phys Rev B 90, 205422 (2014).
National Key Research and Development Program of China (Grant No. 2017YFA0205700), National Basic Research Program of China (Grant No. 2015CB932403, 2017YFA0206000), National Natural Science Foundation of China (Grant Nos. 11674012, 61521004, 21790364, 61422501, and 11374023), Beijing Natural Science Foundation (Z180011, and L140007), and Foundation for the Author of National Excellent Doctoral Dissertation of PR China (Grant No. 201420), National Program for Support of Top-notch Young Professionals (Grant No. W02070003).
引用本文： Li B W, Zu S, Zhang Z P, Zheng L H, Jiang Q et al. Large Rabi splitting obtained in Ag-WS2 strong-coupling heterostructure with optical microcavity at room temperature. Opto-Electron Adv 2, 190008 (2019).
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