News

Fri, 08/24/2018

In a newly-published Rapid Communication, we have shown how the chiral anomaly in Weyl semimetals admits an analogue of "adiabatic demagnetization", which is a technique for low-temperature refrigeration. The idea is that abruptly turning on or off the chiral anomaly (by switching on/off...

Fri, 06/29/2018

In a new paper, Liang Fu and I have shown that one can achieve record-efficient thermoelectric performance using three-dimensional nodal semimetals (Dirac or Weyl semimetals) in a strong magnetic field.  The work is ...

Fri, 06/29/2018

In a recently-published series of papers, I explored the problem of the "tunneling anomaly" in bilayers of composite Fermions, together with Debanjan Chowdhury and Patrick Lee.  Our goal was to explain a recent series of experiments by Jim Eisenstein et. al. at Caltech, which observed a...

Tue, 02/13/2018

At a recent workshop at the Banff International Research Station, I gave a talk about the possibility of huge thermopower in nodal semimetals.  You can watch the seminar at the link below, or read the preprint at https://arxiv.org/abs/1706.06117

Thu, 01/04/2018

I have been invited to discuss my recent work on semimetals at a number of universities.  The title of the talk is "Semimetals Unlimited", and I discuss ways in which nodal semimetals can overcome the limits on electron mobility and thermopower that constrain semiconductors.

Caltech: Nov...

Wed, 10/11/2017

Together with Sergey Syzranov, I studied the conductivity of nodal line semimetals. These turn out to be qualitatively different from other semimetals, like Weyl or Dirac semimetals, because of an unusual screening that changes the nature of the Coulomb potential from 1/r to 1/r^2.  Most...

Thu, 09/29/2016

A new paper in Nature Communications describes experiments that examine the "extreme quantum limit" of magnetic field in the material strontium titanate.  We find evidence of a drastic reduction of the Fermi energy driven by the magnetic field, which leads to the formation of a spatially...

Mon, 08/29/2016

In a recent paper, Tianran Chen and I identified an interesting fractal structure of hopping conduction pathways in compensated semiconductors.  The finding implies that hopping conductivity is unusually large and robust in these systems, and can appear two-dimensional even in a 3D system.

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Mon, 06/27/2016

In a series of recent papers, I explored ways to make bosonic particles with unusual properties using bilayer electronic systems.  These works suggest new ways to realize quantum phases and quantum phase transitions of 2D bosons.

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Thu, 04/14/2016

I am giving a seminar at the Applied Math Lab at NYU's Courant Institute in New York City.