School of Physics Colloquia

Monday 30th April 2018

Dr Neil Barrie (Tokyo) and Mr Xiang Zhang (CUDOS, USyd)
Special Student Colloquium

Title: Pendulum Leptogenesis (Dr Neil Barrie (Kavli Institute for the Physics and Mathematics of the Universe, Tokyo)


One of the major unsolved problems in modern physics is the origin of the observed matter antimatter asymmetry of the universe. A leading paradigm to solve this mystery is known as Leptogenesis, in which the asymmetry is originally generated in the neutrino sector. We propose a new scenario for a non-thermal Leptogenesis mechanism that takes place during the reheating epoch following inflation. The interplay between the oscillation of the inflaton during reheating and a scalar lepton leads to a dynamical system that emulates the well known forced pendulum. This is found to produce driven motion which leads to the generation of a non-zero lepton number density, which is later redistributed into baryons. This model successfully reproduces the observed matter-antimatter asymmetry, while simultaneously providing an origin for neutrino masses via the seesaw mechanism.

Title: Single and entangled photon manipulation for photonic quantum technologies (Mr Xiang Zhang (CUDOS, USyd)


Photonic quantum technologies which harness the fundamental laws of quantum physics opens the possibility of unprecedented computational power on specific problems as well as unconditional information security in communication network. With significant recent investment and major progress, its practical applications are nearly within the technological reach. One of the remaining challenges for quantum computing and communication are the on-demand single photon sources and integrated time-bin entanglement circuits. This presentation will be separated into two parts that explain our strategies to address these two challenges. The first part explains a novel multiplexing schemes for efficient single photon generation, while the second part explains our integrated silicon nitride platform for time-bin entanglement generation, manipulation and analysis. A succinct outlook and conclusion will end this presentation

Monday 30th April 2018, 3:00pm, Slade Lecture Theatre, Physics Building A28

Cake and coffee are served at all School Colloquia.

Future Colloquia