Title: Modelling Organic Condensates From Weak To Strong Coupling.
When: Wednesday, January 25, (2017), 12:00.
Place: Department of Condensed Matter Physics, Faculty of Science, Module 3, Seminar Room (5th Floor).
Speaker: Jonathan Keeling, SUPA - School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, United Kingdom.
The idea of studying strong matter-light coupling using organic molecules has a long history , but has recently seen an explosion of experimental interest . In particular exciton-polariton lasing and condensation has now been observed in a variety of organic media, including anthracene, organic polymers, and fluorenes. Closely related to these strong coupling polariton condensates is the observation, in weak coupling, of Bose-Einstein condensation of photons in a dye-filled microcavity . These experiments pose several questions about the relation of condensation and lasing, and about the role of vibrational modes in the physics of photon and polariton condensation. I will discuss our recent work on these subjects.
In the context of photon condensation, I will discuss the role of vibrational modes in establishing a thermal distribution of photons , including the time-evolution toward the thermal state. In the context of polariton condensation I will discuss our recent work exploring the nature of the ground and excited states of a model of such a system [5,6]. In particular, I will focus on the connections to optomechanics in other systems, and changes in the optical properties that can arise from coupling to vibrational modes.
1. Agranovich, The Theory of Excitons (Nauka, 1410.6632. Moscow, 1968). Excitations in Organic Solids, (Oxford University Press, Oxford, 2009).
2. Kena-Cohen and Forrest, Nat. Photon. 4 371 (2010). Plumhof et al Nat. Mater. 13 247 (2014); Daskalakis et al, ibid 271.
3. Klaers et al, Nature 468 545 (2010).
4. Kirton and Keeling, Phys. Rev. Lett. 111, 100404 (2013), arXiv: 1410.6623.
5. Cwik et al, Eur. Phys. Lett. 105, 47009 (2014).
6. M. A. Zeb, P. G. Kirton, J. Keeling, arXiv:1608.08929.