Abstract
Flow of the normal fluid component of He II about a cylinder and flat plate in a channel with a square cross-section was observed by tracking clouds of He2∗ excimers. Flow was produced using a lithographically patterned heater. The direction and speed of flow projected onto a plane parallel to the axis of the channel and perpendicular to the heater exhibited significant change with time even after the heater was turned off. Flow was recorded in movies. Excimers moved at least as fast as could be recorded by the camera. Velocity vector field maps of flow suggest formation of structures downstream of the cylinder object that are consistent with parts of eddies. In this paper, we establish a foundation to observe normal component flow of a quantum fluid over centimeters.
Original language | English |
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Article number | 174501 |
Journal | Physical Review B |
Volume | 107 |
Issue number | 17 |
DOIs | |
State | Published - May 1 2023 |
Funding
This paper used resources at the Spallation Neutron Source, a U.S. Department of Energy (DOE), Office of Science User Facility operated by the Oak Ridge National Laboratory (ORNL). ORNL is managed by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725. Fabrication of the labyrinth heater was supported by the Center for Nanophase Materials Sciences, which is a DOE, Office of Science User Facility at ORNL. X.W. acknowledges support from the Shull Wollan Center Graduate Research Fellowship program and the Graduate Advancement, Training and Education program of University of Tennessee. W.G. acknowledges the support from the National Science Foundation under Grant No. DMR-2100790 and the National High Magnetic Field Laboratory, which is supported by National Science Foundation Cooperative Agreement No. DMR-2128556 and the State of Florida.