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arXiv · 1407.1515

Evidence for Supersolidity in Bulk Solid $^4$He

Xiao Mi·Anna Eyal·Artem V. Talanov·John D. Reppy
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Abstract

We report low temperature measurements of bulk solid $^4$He in a two-frequency compound torsional oscillator with both annular and open cylinder sample geometries. The oscillators were designed to suppress period shifts arising from all known elastic effects of solid $^4$He. At temperatures below 0.25 K, period shift signals similar to those reported by Kim and Chan [Science {\bf 305}, 1941 (2004)] were observed, albeit two orders smaller in magnitude. A sizable fraction of the observed signals are frequency-independent and consistent with the mass-decoupling expected for supersolid $^4$He. This result is in stark contrast with recent works on Vycor-solid-$^4$He system and suggests that a small supersolid fraction on the order of $1 \times 10^{-4}$ may indeed exist in bulk solid $^4$He.

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Xiao Mi, Anna Eyal, Artem V. Talanov, John D. Reppy. 2014-07-06. Evidence for Supersolidity in Bulk Solid $^4$He. https://arxiv.org/abs/1407.1515

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