Quantum Lunch Location:
T-Division Conference Room, TA-3,
Building 123, Room 121
Quantum Institute: Visitor Schedule
The Quantum Lunch is regularly held on Thursdays in the Theoretical Division Conference Room, TA-3, Building 123, Room 121.
For more information, contact Diego Dalvit.
May 14, 2007
Monday 4:00 PM
University of Maryland
Visualizing the Formation and Dynamics of Quantum Defects in 4He Using Hydrogen Ice
In superfluid helium 4, quantum vortices have been studied indirectly for
nearly fifty years. We have discovered that micron sized solid hydrogen
particles suspended within superfluid helium are attracted to and trapped
by the vortex filaments and thereby make it possible to see individual
vortex lines. We compare the line density in a steadily rotating
superfluid with the Feynman prediction. Our observations also include
periodic particle spacing on lines at low particle density,
complex vortex branching, networks, and vortex reconnection. Our
visualization technique makes it possible to observe the dynamics and
geometry of vortices both in superfluid turbulence and in quench conditions
passing through the phase transition.
G.P. Bewley, D.P. Lathrop, K.R. Sreenivasan, "Superfluid helium:
visualization of quantized vortices," Nature 441, 588 (2006).