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

Daniel Lathrop,
University of Maryland

Visualizing the Formation and Dynamics of Quantum Defects in 4He Using Hydrogen Ice

Abstract

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).