School of Physics Spring Colloquium Series- Dr. Andrea Young

Speaker: Dr. Andrea Young

Host: Claire Berger

Title: Superconductivity and magnetism in crystalline graphite allotropes

Abstract: Humanity makes great use of the electric field effect: charging and discharging capacitors in low density semiconductors systems is the underpinning of the analog and digital electronics that define our age. At the same time, we know quantum mechanics allows for a larger variety of phases than just electrical conductors and insulators.  I will describe the physics of crystalline graphite multilayers with rhombohedral stacking, where the competition between electron hopping within- and between- the graphene planes leads to a flat dispersion characterized by high electronic density of states and Berry curvature, which can be tuned by a perpendicular electric field.  Using electrostatic gates to tune both this interlayer potential and the total carrier density, I will show that a dizzying variety of magnetic and superconducting states can be realized, often within the same device. The exceptional experimental reproducibility of these structurally simple systems allows us to investigate a variety of correlated electron phenomena, including the mechanisms of unconventional superconductivity and new device functionalities enabled by nanoscale electrostatic control over correlated phases of matter.  

Bio: Andrea Young received his PhD from Columbia University in 2012 under Philip Kim.  After postdoctoral positions at MIT and the Weizmann Institute of Science, he joined the faculty at the University of California, Santa Barbara in 2015.  His work work on correlated phases in van der Waals heterostructures has been recognized with numerous awards, including the New Horizons Prize, McMillan Award, and Presidential Early Career Award for Scientists and Engineers.