Applied
Superfluidity Group
Research
Overview
In Bose-Einstein condensates, ~1023
atoms can occupy the same quantum ground state and behave in many ways
as a single entity. We are interested in not only studying fascinating
properties of such state of matter but also applying them as a set of
tools to elucidate the subtleties of the quantum world. One of our
current focuses is the development and applications of unique matter
wave quantum interference devices that are built on the superfluid 4He
Josephson phenomena.
Superfluid 4He
Josephson
Phenomena & Matter Wave Interferometers
 Arrays
of nanoscale apertures have been found to exhibit the characteristic
signatures of Josephson weak links in superfluid 4He
near its transition temperature. We have successfully constructed
superfluid quantum interference devices by placing two (and more)
superfluid
Josephson junctions in a superfluid torus as in a dc-SQUID. This new
type of interferometer has been configured as a gyroscope to monitor
small rotation and also as a more general "phase meter" to detect
quantum mechanical phase differences in superfluid condensate. We
continue
to develop unique 4He
matter wave
interferometers and new experimental techniques to explore their
ultimate sensitivity and utility.
Rotation Sensing /
Gyroscope
 We
have demonstrated that superfluid versions of dc-SQUID can be extremely
sensitive sensors for absolute rotation through what is known as the
Sagnac phase shifts. By taking advantage of the macroscopic coherent
nature of our BEC system, we are developing more sensitive and more
practical superfluid gyroscopes to contribute to fields such as
seismology, geodesy, inertial navigation, and general relativity.
Using Superfluid
Interferometers to Probe
Fundamental Physics
 We
are working on further developing our matter wave interferometers to
investigate novel interactions that give rise to quantum mechanical
phase shifts in a neutral matter system. With an asymmetric superfluid
interference grating (which works as an absolute gauge for quantum
mechanical phase differences), we are also probing the subtleties of
the quantum phases that describe the condensate. |
