Fall 2017

Recent general results on the statistics of nonequilibrium processes have opened up old debates between the exact dynamical and informational viewpoints on probability.  Many of the good properties of equilibrium systems are not rigorously provable without assuming ergodicity.  It turns out those arguments are even more relevant, and more pernicious, when working in a dynamical context.  Even though nonequilibrium research predates traditional equilibrium thermodynamics, it is still seen by many as a vast, uncharted territory.  In this talk, I show how there is a growing...

Recent progress in the understanding of non-equilibrium quantum dynamics of many-body systems will be discussed. Applications to electron systems and ultracold atoms will be considered. Examples include photo-induced Cooper pairing in superconductors, prethermalization in 1d condensates, mesonic resonances in the Fermi Hubbard model. Possible connections of these phenomena to other areas of physics will be pointed out. 

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Graphene, a single layer of carbon atoms arranged in a hexagonal lattice, is probably the best known, and most extensively characterized two-dimensional material.  However, this represents just one of a larger class of van der Waals materials, in which atomic monolayers can be mechanically isolated from the bulk.  By integrating these materials with one another,  an exciting new opportunity has emerged in which layered heterostuctures can be fabricated with properties beyond those of the constituent materials. In this talk I will present some of our recent efforts where...

The laws of thermodynamics are fundamental laws of nature that classify energy changes for macroscopic systems as work performed by external driving and heat exchanged with the environment. In the past decades, these principles have been successfully extended to the level of classical trajectories of microscopic systems to account for thermal fluctuations. In particular, experimentally tested generalizations of the second law, known as fluctuation theorems, quantify the occurrence of negative entropy production. The extension of thermodynamics to include quantum...

The quantum Hall effect, discovered 35 years ago, is a bizarre phenomenon in which a 2D gapped system can nevertheless carry a current.  Moreover, the transverse conductivity of the system is precisely quantized in units of e^2/h.  Unfortunately, this behavior requires a strong perpendicular magnetic field, and has only been observed at low temperatures.  Work of Haldane in 1988 raised the possibility that similar physics could be observed in two-dimensional magnetic systems without any external magnetic field, and potentially at much higher temperatures.  Such a system is known as a "...