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Center for Nonlinear Studies |
Liquid He-4 enters into a superfluid state and flows without any friction below 2.176K. Recent torsional oscillator measurements of solid helium confined in porous media [1] and in bulk form [2] found superfluid-like behavior below 0.2K. These measurements have been replicated in many laboratories. A specific heat peak (3) that appears to be related to the onset of superfluid-like behavior was also found. However, there are many outstanding puzzles (4) including the absence of some ‘standard’ signatures of superfluidity such as dc-mass superflow and second sound. In this talk I will provide a report on the experimental status of the subject. 1. E. Kim and M.H.W. Chan, Nature 427, 225 (2004) 2. E. Kim and M.H.W. Chan, Science 305, 1941(2004). 3. X. Lin, A.C. Clark and M.H.W. Chan, Nature 449, 1025 (2007); X. Lin, A.C. Clark, Z. G. Cheng and M.H.W. Chan, PRL 102, 125302 (2009). 4. M.H.W. Chan, Science 319, 1207 ( 2008)
Host: Cristiano Nisoli, T-4/CNLS