Speaker
Hari Manoharan
(Stanford University)
Description
Deforming a material and restoring it precisely back to its
starting point intuitively implies that the material before
and afterwards is identical. This is true classically, and was
believed to be true in general until recently in the history of
quantum mechanics. Even if all the atoms, electrons, and
other ingredients are returned exactly to where they
started, we now know that the restored material can differ
from the undeformed material by nontrivial quantum
mechanical phase factors. These Berry phases have
garnered increasing appreciation in recent years, and in
condensed matter they arise from the topology of electronic
states and embedded degeneracies. Such considerations
have helped to identify new ground states consisting of
topologically ordered matter, which can be exploited in
quantum devices, quantum computing strategies, and in
searches for exotic particles. This talk will overview new
experiments from our lab, employing scanning tunneling
microscopy and atomic manipulation, that directly visualize
and control topological order in several materials and
nanostructures.
