Quantum Fluids of Polariton Condensates: from fundamental phenomena to "polariton" logics

Polaritons are light-matter particles formed by a strong interaction between the electronic excited states in a semiconductor and the light field of a microcavity. Recently, polaritons have attracted particular attention for their capacity to undergo phase transition to a collective coherent state in a similar way to the standard Bose-Einstein condensation demonstrated in ultracold gases [1]. However, they offer strong advantages compared to their atomic counterparts, among which a much higher temperature of condensation, the ability to be easily manipulated/observed and the possibility of straightforwardly integrate with present semiconductor technology, which opens new ways for the use of condensate in novel futuristic devices.

In this talk we will review some of the most interesting and significant physical phenomena associated with polariton condensation. Indeed, due to their intrinsic dissipative nature, polariton condensates possess an incredibly rich phenomenology of quantum effects which span from the manifestation of superfluid flow [2,3] and quantized circular currents [4] to the exhibition of a complex and important dynamics of vortex formation and migration [5].

Furthermore, given their strong non-linearities and very high propagation velocities (1% the speed of light), polariton condensates are particularly attractive for their potential use as optical switches in integrated circuits. In particular we can see that it is possible to realize a polariton-based transistor for logic gates made out of polariton fluids [6].

[1] J. Kasprzak, M. Richard, S. Kundermann, et al., Nature 443, 409 (2006).

[2] A. Amo, D. Sanvitto, F. P. Laussy, et al. Nature 457, 291 (2009).

[3] A. Amo, J. Lefrère, S. Pigeon, et al., Nat. Phys. 5, 805 (2009).

[4] D. Sanvitto, F. M. Marchetti, M. H. Szymanska, et al., Nat. Phys. 6, 527 (2010).

[5] D. Sanvitto, S. Pigeon, A. Amo et al. Nat. Phot. 5, 610 (2011).

[6] D. Ballarini, M. De Giorgi, et al. arXiv:1201.4071 (2012).

Work sponsored under the POLAFLOW ERC project