Dr. Fangyuan Yang Colloquium - VIA ZOOM

Dr. Fangyuan Yang from the Vienna University of Technology will present a colloquium to the Department of Physics and Astronomy.

Talk Title and Abstract:

Unravelling correlated electronic states in graphene by thermodynamic measurements

Strong Coulomb interactions in narrow electronic bands give rise to emergent quantum phases that promise to revolutionize electronic devices. Understanding these correlated electronic phases remains a major challenge in condensed matter physics. Van der Waals(vdW) materials have become an active playground for investigating strongly correlated electrons because they allow the realization of narrow electronic bands by applying strong magnetic fields (Landau levels) or by engineering flat bands using moiré superlattices. In this talk, I will discuss a technique for measuring thermodynamic quantities in vdW heterostructures that provides unique insights into strongly correlated states and unveils hidden phase transitions. The technique relies on electrostatic sensing, which makes it possible to precisely measure chemical potential, entropy and magnetization despite the negligible sample volume of vdW devices. First, I will discuss how this method enables us to quantitatively understand fractional quantum Hall and electron bubble phases in monolayer graphene. Second, I will tell about how this method enables the discovery of the Pomeranchuk effect in twisted bilayer graphene. Finally, I will discuss possible future applications of thermodynamic measurements in vdW heterostructures.

Join Zoom Meeting
https://uwaterloo.zoom.us/j/92551810931?pwd=eTZFWmp1aXkvSjlwMFF4eUxuZEZDdz09

Meeting ID: 925 5181 0931

Passcode: 489334