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Physics Colloquium

Thursday, May 18, 2023
4:00pm to 5:00pm
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Online and In-Person Event
Nonlinear Topological Photonics
Mikael Rechtsman, The Pennsylvania State University,

In 2005, Duncan Haldane and Sri Raghu had the insight that aspects of quantum Hall physics were not unique to electrons, but could apply more broadly, in particular to light in photonic crystals.  This then led to the observation of photonic chiral edge states, which are immune to backscattering.  In the first part of my talk I will propose a potential integrated photonic application that is unique to topological systems: wide band, disorder-resistant slow light. In the second part, I will present my group's recent experimental work in which we use optical nonlinearity to induce mean-field interactions in a photonic Thouless pump, and show that soliton motion is sharply quantized to the Chern number in the low power regime.  At intermediate power, nonlinear bifurcations give rise to fractional quantization of soliton motion.  This behavior emerges from the interplay of inter-photon interactions and topological bands, and seems to have no direct electronic counterpart.    

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Meeting ID: 858 1199 4621

The colloquium is held in Feynman Lecture Hall, 201 E. Bridge.

In person is open to those with a valid Caltech ID.