DOE Experimental Condensed Matter PI meeting, Day 2

 More highlights from the meeting.  Office hours for my class conflicted with a couple of the talks, so these are briefer than I would've liked.

• It is possible to use coherent x-ray scattering to look at time variations in the domain structure of an antiferromagnet.  In the magnetic diffraction pattern there is speckle near the magnetic Bragg spots that bops around as the domain structure fluctuates.
• Amorphous magnetic alloys can show some really wild spin textures.  
• By growing a few nanometers of a paramagnetic metal, Bi2Ir2O7, on top of an insulating spin ice, Dy2Ti2O7, it's possible to get enough coupling that field-driven spin ice transitions can generate magnetoresistance signatures in the metal layer.
• Square planar nickelates can look a lot like the copper oxide superconductors in terms of band dispersion and possible "strange" metallicity.
• Some rare-earth intermetallic compounds can have an impressively rich magnetic phase diagram.
• I learned that some pyrochlore iridates can exhibit a kind of topological metallic state with giant anomalous Hall response.
• I had not previously appreciated how wild it is that one can engineer ferroelectric response in stacks of 2D materials that are not intrinsically ferroelectric, as in hBN or even WSe2.
• Ultrasound attenuation can be a heck of a tool for looking at superconductivity and other electronic transport properties.
• Strontium titanate remains a really interesting test case for understanding exotic superconductivity, with its superconducting dome as a function of doping, very low carrier density, and incipient ferroelectricity.  Phonons + paraelectric fluctuations + spin-orbit coupling appear to be the big players. 
• A related system in the sense of near-ferroelectricity and low carrier density is at interfaces of KTaO3.
• This experiment in graphene/hBN/graphene stacks (with encapsulating hBN and graphite top and bottom gates) is an extremely pretty, tunable demonstration of superfluidity of bilayer excitons, an effect previously seen in one limit in GaAs systems.