IQIM Postdoctoral and Graduate Student Seminar

Note special time for the Feb. 13 talk. It begins at 2 pm in 114 E. Bridge.

Abstract: In the past decade, moiré materials have revolutionized how we engineer and control quantum phases of matter. I will describe two recent efforts to push moiré quantum phases into (1) higher dimensions and (2) higher topological numbers. First, I will discuss a new family of three-dimensional bulk moiré metals with a one-dimensional superlattice which exhibit quantum oscillations with a remarkably high degree of order. We find that the Fermi surface is comprised of over 40 distinct cross-sectional areas, near the most observed in any material. This can be naturally understood in a framework in which bulk moiré materials encode electronic properties of higher-dimensional superspace crystals in ways that parallel well-established crystallographic methods used for incommensurate lattices. Next, I will discuss a theoretical proposal which can use such one-dimensionally modulated materials to realize Hall crystals, in which crystallization gives rise to electronic topology, with various higher Chern numbers. These phases shed light on a regime of moiré materials in which interactions and topology coexist, and could provide a setting for beyond-conventional fractional quantum Hall phases.

Refreshments will be provided following the talk.