PHYS/ASTR Colloquium: "Imaging Quantum Chaos in Electronic Graphene Billiards" - Dr. Jairo Velasco (Assoc. Prof., U.C. Santa Cruz)

Abstract: The harnessing and manipulation of electronic states in quantum materials has the

potential to revolutionize computation, sensing, storage, and communications, thus impacting

multiple facets of our everyday lives. In this talk I will discuss my group’s recent experiments

with graphene, a highly versatile carbon-based quantum material that hosts ultra-relativistic

charges. Specifically, I will focus on an experiment that utilizes confinement, nanoscale

visualization, and spectroscopy to reveal new properties of the ultra-relativistic states hosted

by stadium shaped graphene-based billiards. This structure enables the first imaging of the

highly elusive quantum scar states, which consist of an enhanced wavefunction probability

density along unstable classical periodic orbits and are a smoking gun for quantum chaos.

Notably, chaotic systems are sensitive to perturbations and could lead to remarkable devices if

they can be harnessed. Therefore, the study of quantum scar states provides a pathway

towards the development of new types of quantum devices.

Speaker Bio: Dr. Jairo Velasco Jr. is an Associate Professor of Physics at the University of

California Santa Cruz. His research interests include the study of electronic properties and

structure of two-dimensional materials. He received his PhD in physics from the University of

California Riverside in 2012 with Jeanie Lau. He was then a President’s Postdoctoral Fellow in

Mike Crommie’s group at the University of California Berkeley from 2012-2015. Dr. Velasco is a

recipient of the NSF early CAREER award (2018) and the Gordon and Betty Moore Foundation

Experimental Physics Investigator Award (2022).