EMANUELE DISTANTE 'Quantum Optics with Single Photons and Highly Excited Rydberg States'

Strong interaction between individual single photons would enable a new regime of non-linear optics and unlock several applications in quantum information science including photon-photon gates and deterministic Bell-state measurements for quantum networking. To achieve this longstanding goal a highly nonlinear medium which can mediate the interaction between photons is required. A promising strategy is to combine electromagnetically induced transparency (EIT) and Rydberg atoms. With EIT one can coherently map photon into highly excited Rydberg states of an atomic ensemble. The dipole-dipole interaction between these states mediates the interaction between photon. In this talk, I will give a brief introduction on Rydberg EIT and on its applications to quantum information science. Finally, I will present some recent results from our group which demonstrates the storage and retrieval of a paired single photon emitted by an ensemble quantum memory in a strongly non-linear medium based on highly excited Rydberg atomic excitations.


VAHAGN MKHITARYAN 'GST as a Tuneable Material for Optical Applications'

The functionalities of a wide range of optical and opto-electronic devices are based on resonance effects and active tuning of the amplitude and wavelength response is often essential. GST (Ge2Sb2Te5) is a binary material which demonstrates two or more stable material phases with large optical contrast between them. Tuning is achieved by triggering phase transitions from one state to another by means of thermal, electrical or optical excitation. In this talk I will demonstrate two applications where we have used GST to tune the optical response of the resonant structures: tuning the plasmonic resonances of periodic arrays of holes drilled in thin metal films; and a perfect absorber design that incorporates the tenability of the phase change materials to achieve absorption contrast in the proposed structure.


PhD Seminar, June 10, 2016, 17:00. Seminar Room