Princeton University

School of Engineering & Applied Science

Topological Features of Photonics Systems

Mohammad Hafezi
E-Quad, B205
Wednesday, January 15, 2014 - 4:30pm

Topological features – global properties which are not discernible locally – emerge in systems from liquid crystals to magnets to fractional quantum Hall systems. Deeper understanding of the role of topology in physics has led to a new class of matter: topologically-ordered systems. The best known examples are quantum Hall effects, where insensitivity to local properties manifests itself as conductance through edge states that is insensitive to defects and disorder.

In this talk, I demonstrate how similar physics can be observed for photons; specifically, how various quantum Hall Hamiltonians can be simulated with linear optical elements. I report on the first observation of topological photonic edge state using the silicon-on-insulator technology. Furthermore, the addition of optical nonlinearity to the system leads to the possibility of implementing fractional quantum Hall states of photons and anyonic states that have not yet been observed. In particular, I discuss a scheme to engineer three-body interaction, which is absent in nature, to implement some of the fractional quantum Hall models, in the context of circuit-QED.
Mohammad Hafezi received his diplome d'ingenieur from Ecole Polytechnique (Paris) in 2003 and his Ph.D. from Physics Department at Harvard University in 2009. He moved to the Joint Quantum Institute (NIST/University of Maryland) as a research associate and since 2012 he is a research faculty. His research is at the interface of theoretical quantum optics and condensed matter physics with a focus on fundamental physics and applications in quantum information science, precision measurement and integrated photonics.