Speaker
Emil Bergholtz
(FU Berlin)
Description
A large number of recent work points to the emergence of
intriguing analogues of fractional quantum Hall states in
two-dimensional lattice models due to effective interactions
in nearly flat bands with Chern number C=1. In principle,
this opens up a number of intriguing possibilities including
lattice realizations of quantum Hall phenomena and anyons
at room temperature. Here, I will discuss three related
topics.
First, I will discuss for which filling fractions there is
numerical evidence for fractional Chern insulators
(incompressible states), including new evidence for several
abelian hierarchy of states, and also point out some
important differences compared to conventional Landau
level physics and the emergence of competing compressible
phases.
Second, I will introduce a minimal solvable model describing
a “thin-torus” version of a fractional Chern insulator.
Third, I will discuss the physics in flat bands with higher
Chern number and possible realizations thereof in quasi-
two-dimensional slabs of pyrochlore based transition metal
oxides as well as correlated states within these bands.
