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ABSTRACT Liquid 4He enters the superfluid state and flows without friction below 2.176 K. Thin liquid films adsorbed on solid substrates undergo the same transformation, although at a lower

temperature. When the substrate is subjected to oscillatory motion a portion of the film, known as the superfluid fraction, decouples from the oscillation. A similar phenomenon has been

observed1,2 in solid 4He, in which a fraction of the solid seems to decouple from the motion of the surrounding lattice. Although this observation has been replicated in various

laboratories3,4,5,6, no thermodynamic signature of the possible supersolid transition has been seen. Here we report the finding of a heat capacity peak that coincides with the onset of mass

decoupling. This complementary experimental evidence supports the existence of a genuine transition between the normal solid and supersolid phases of 4He. Access through your institution Buy

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OTHERS CROSSOVER FROM GAS-LIKE TO LIQUID-LIKE MOLECULAR DIFFUSION IN A SIMPLE SUPERCRITICAL FLUID Article Open access 16 May 2024 QUASI-EQUILIBRIUM PHASE COEXISTENCE IN SINGLE COMPONENT

SUPERCRITICAL FLUIDS Article Open access 30 July 2021 UNIVERSAL KIBBLE–ZUREK SCALING IN AN ATOMIC FERMI SUPERFLUID Article 29 July 2024 REFERENCES * Kim, E. & Chan, M. H. W. Probable

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Rev. Lett._ 83, 4800–4803 (1999) Article  CAS  ADS  Google Scholar  Download references ACKNOWLEDGEMENTS We thank J. A. Lipa for the 1 p.p.b. purity helium, and J. Jain, J. S. Kurtz and N.

Mulders for their advice. Funding was provided by the National Science Foundation. AUTHOR CONTRIBUTIONS X.L., A.C.C. and M.H.W.C. contributed equally to this work. AUTHOR INFORMATION AUTHORS

AND AFFILIATIONS * Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA X. Lin, A. C. Clark & M. H. W. Chan Authors * X. Lin View author

publications You can also search for this author inPubMed Google Scholar * A. C. Clark View author publications You can also search for this author inPubMed Google Scholar * M. H. W. Chan

View author publications You can also search for this author inPubMed Google Scholar CORRESPONDING AUTHOR Correspondence to M. H. W. Chan. ETHICS DECLARATIONS COMPETING INTERESTS The authors

declare no competing financial interests. SUPPLEMENTARY INFORMATION SUPPLEMENTARY INFORMATION The file contains Supplementary Figure and Legend and Supplementary Discussion. The figure

shows the temperature dependence of the specific heat of the four samples with the constant specific heat term of the 10 ppm and 30 ppm samples, deduced from Fig.3, subtracted. We further

discuss: 1) Previous heat capacity measurements below 200 mK; 2) Accuracy and uncertainty in the 3He concentration of the samples studied; 3) High temperature deviation from the Debye

specific heat; 4) Additional comments on the constant specific heat term found for the 10 ppm and 30 ppm samples; 5) Evidence against phase separation as the origin of the 75 mK peak. (PDF

153 kb) RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Lin, X., Clark, A. & Chan, M. Probable heat capacity signature of the supersolid transition.

_Nature_ 449, 1025–1028 (2007). https://doi.org/10.1038/nature06228 Download citation * Received: 03 July 2007 * Accepted: 07 September 2007 * Issue Date: 25 October 2007 * DOI:

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