University of Melbourne, Australia Title: Photon behaviour in arrays of coupled cavities containing single two level atoms.

Date/Time: Tuesday, 16th September 2008 / 15:00- - ()

Speaker: Ms. Melissa Makin (the University of Sydney)

Single photonic cavities containing a single two level atom have been predicted to exhibit a special behaviour called photon blockade, where the presence of a single photon within the cavity can prevent subsequent photons from entering. This behaviour has been demonstrated recently (Birnbaum et al, Nature, 436, 87, 2005). In this talk I will discuss 1D arrays of photonic cavities (linked together through evanescent coupling), each cavity containing a single two level atom in the photon blockade regime. This system is described by the Jaynes Cummings-Hubbard Hamiltonian. In particular I will discuss the behaviour of a single photon placed in the end cavity of such a 1D array - how does it travel through the system? In the restricted subspace of a single excitation (either photonic or atomic) we have diagonalised the Hamiltonian. Hence, I will show that unusual behaviour could be achieved, for example: slowing the progress of the photon, and effectively splitting the photon into two distinct pulses. The ultimate goal of such coupled array devices is to understand quantum phase transitions in optical settings, and to realise a quantum simulator.