Tying Knots in a Quantum Fluid

Tying Knots in a Quantum Fluid
David S. Hall, Amherst College
 David S. Hall
Date and time: Wed, Oct 23, 2019 - 4:00pm
Refreshments at 3:45pm
Location: Hasbrouck 134
Category: Departmental Colloquium

Knots are familiar entities that appear at a captivating nexus of
art, technology, mathematics, and science. They have recently
attracted significant experimental interest in contexts ranging
from knotted DNA and nanostructures to nontrivial vortex knots in
classical fluids. In this talk I will discuss the first controlled
experimental creation and detection of knot solitons, which are
particle-like topological excitations possessing a knotted field
character. The superfluid medium within which they exist is a
Bose-Einstein condensate with a temperature some tens of billionths
of a degree above absolute zero. In addition to enabling future
experimental studies of their properties and dynamics, these knot
solitons provide a striking demonstration of the celebrated Hopf
fibration, which mathematically tie together many seemingly
unrelated physical phenomena.