DOE Experimental Condensed Matter PI meeting, Day 1

Somehow I found the first day of the virtual meeting more exhausting than when we do these things in person, probably because I had to go teach in the middle of the event.  A sampling of highlights:

• Rather than relying on relatively crude methods to create defect centers in diamond for quantum sensing (or qubit purposes), one can use chemistry to build transition metal complexes with designer ligand fields (and hence energy level structures), as demonstrated here.
• I know understand better why it has historically been so difficult to demonstrate, experimentally, that the quasiparticles in the fractional quantum Hall effect obey fractional (anyonic) statistics.  In an interferometer, it's critical to use screening (from top and bottom electron gases that act like capacitor plates) to reduce Coulomb interactions between edge states and the bulk. Once that's done, you can see clear evidence of fractional (anyonic) phase slips.
• Some truly exceptional people can still do research even while being a university president.  At very low energies in an Ising ferromagnet with an in-plane magnetic field, hyperfine interactions can lead to hybridization of magnetic levels and the formation of "electronuclear" spin excitations.
• Ultraclean ABC-stacked graphene trilayers can show remarkably rich response, dominated by strong electron-electron interaction effects.
• High quality crystal growth can drastically lower the defect densities in transition metal dichalcogenides.  That makes it possible to construct bilayers of WSe2, for example, that can host apparent excitonic condensates.  Similar physics can be seen in MoSe2/WSe2 bilayers, where it is clear that exciton-exciton interactions can be very strong.
• Pulling and pushing on a sample can lead to elastocaloric effects (like when a rubber band cools upon being stretched), and these can reveal otherwise hidden properties and phase transitions.

More tomorrow.  (One fun idea from a colleague:  Perhaps the program officers have hidden a secret easter egg token somewhere in the Gather virtual poster area, and whoever finds it gets a bonus award supplement to support a summer undergrad....)