Room-temperature Bose–Einstein condensation of cavity exciton–polaritons in a polymer

Abstract

A Bose-Einstein condensate (BEC) is a state of matter in which extensive collective coherence leads to intriguing macroscopic quantum phenomena. In crystalline semiconductor microcavities, bosonic quasiparticles, known as exciton-polaritons, can be created through strong coupling between bound electron-hole pairs and the photon field. Recently, a non-equilibrium BEC (ref. ) and superfluidity have been demonstrated in such structures. With organic crystals grown inside dielectric microcavities, signatures of polariton lasing have been observed. However, owing to the deleterious effects of disorder and material imperfection on the condensed phase, only crystalline materials of the highest quality have been used until now. Here we demonstrate non-equilibrium BEC of exciton-polaritons in a polymer-filled microcavity at room temperature. We observe thermalization of polaritons and, above a critical excitation density, clear evidence of condensation at zero in-plane momentum, namely nonlinear behaviour, blueshifted emission and long-range coherence. The key signatures distinguishing the behaviour from conventional photon lasing are presented. As no crystal growth is involved, our approach radically reduces the complexity of experiments to investigate BEC physics and paves the way for a new generation of opto-electronic devices, taking advantage of the processability and flexibility of polymers.

Two-dimensional infrared spectroscopy of vibrational polaritons of molecules in an optical cavity

“…Varying cavity polarization (µ k · e c ) and incident angle (θ) in Eq. 1 using collinear experiments 27 could provide information regarding spatial confinements of several vibrational excitations and possibilities of molecular vibrational condensates like usual electronic polariton condensates in organic [39][40][41] and inorganic 39,42,43 microcavities, if effective dense vibrational polaritons are obtained, which may be possible in larger macromolecules like J-aggregates. Time-varying cavity coupling strengths can be used to study dynamics of efficient cooling of molecular vibrational states for n−polariton manifolds using higher dimensional spectroscopic techniques.…”

Ground‐State Chemical Reactivity under Vibrational Coupling to the Vacuum Electromagnetic Field

“…The coupling of molecular electronic transitions to the vacuum field has been more extensively studied13, 14, 15, 16, 17, 18 than VSC and has already shown many exciting results, such as enhanced conductivity19 and non‐radiative energy transfer,20 lasing,21 and condensation 22. Together with VSC, it clearly opens many new possibilities for molecular and materials science that should be fully explored.…”

Cavity-Enhanced Transport of Charge

“…PACS numbers: 05.60. Gg, 42.50.Pq, 74.40.Gh, The study of strong light-matter interactions [1][2][3][4] is playing an increasingly crucial role in understanding as well as engineering new states of matter with relevance to the fields of quantum optics [5][6][7][8][9][10][11][12][13][14][15][16][17][18], solid state physics [19][20][21][22][23][24][25][26][27][28][29][30][31], as well as quantum chemistry [32][33][34][35][36] and material science [37][38][39][40][41][42][43][44][45][46][47][48][49][...…”