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Published on: September 15, 2016
Brillouin Spectroscopy of Metastable Superfluid Helium-4
Lionel Djadaojee1, Jules Grucker1
1Laboratoire Kastler Brossel, ENS-PSL Université, Sorbonne Université, CNRS, Collège de France, 24 rue Lhomond, 75005 Paris, France.
Abstract:
We report measurements of the Brillouin frequencies of acoustically driven metastable states of superfluid ^{4}He at T∼1 K. This is done using a stimulated Brillouin gain spectrometer operating on a confined spatiotemporal domain (∼40 μm, 200 ns). Our work questions previous experimental results regarding the metastable states of liquid ^{4}He and suggests that thermal effects or vortices can play a significant role in the cavitation process. Thanks to our time-resolved measurements, we also find that it is possible to probe metastable superfluid ^{4}He beyond the commonly defined cavitation threshold.
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