Cuprates and quantum hall systems are two prominent examples of strongly correlated systems. The emerging fields of Moire systems, where 2 crystalline patterns interfere to form a long period modulation, meanwhile shed new light on correlation physics.  I’ll describe 2 gapless states, arising from symmetry constraints, in Moire cuprate systems and half-filled flat Chern bands under periodic magnetic fields.

Twisted cuprates hold promise for high Tc topological superconductivity with robust signatures. While previous predictions are based on simple weakly interacting models, here we examine the vital role played by realistic aspects and correlations that impact the resulting ground states and report a gapless chiral superconductor. We discuss signatures studied in ongoing experiments.

We show that quantum electrodynamics (QED_3), with no well-defined quasiparticles, could emerge in the simple setup of Dirac materials on a vortex lattice.  Tuning electrostatic potential commensurately drives the system into fractional Chern insulators. Physical observables, numerical and experimental prospects are discussed.

Xue-Yang Song obtained her PhD in theoretical condensed matter in 2021 and is currently a Moore postdoctoral fellow at MIT. She studies strongly correlated matter that shows emergent quantum phenomena like fractional excitations and high-temperature superconductivity. She is interested in both developing formal theories and making concrete connections to realistic solid state or synthetic systems. Besides physics, she enjoys cycling and playing with her cat.​