# Abstract:

Composite fermions have played a seminal role in advancing our understanding of the quantum Hall effect, particularly the formation of a compressible composite Fermi liquid (CFL) at filling factor nu = 1/2.  Motivated by experiments on systems ranging from quantum Hall bilayers to 3D bismuth, I will discuss a new kind of multi-layer CFL, wherein interlayer Coulomb repulsion generates metallic' behavior of composite fermions between layers.  Such interlayer coherent CFLs' raise the intriguing possibility that composite fermions may emerge in higher dimensions.  As a concrete example, I will propose that quantum Hall bilayers with nu = 1/2 per layer at intermediate layer separation may host an interlayer coherent CFL, driven by exciton
condensation of composite fermions.  I will discuss the rather remarkable properties of this state, and describe a new sequence of incompressible quantum Hall states that emerge from it at nearby filling factors.  Future experimental and theoretical work will also be discussed, in particular a generalization of this phase to three dimensions.

Toronto Quantum Matter Seminars
Event series  Condensed Matter EventsToronto Quantum Matter Seminars