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Thinning of superfluid films below the critical point

Roya Zandi·Aviva Shackell·Joseph Rudnick·Mehran Kardar·Lincoln Chayes
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Abstract

Experiments on $^4$He films reveal an attractive Casimir-like force at the bulk $λ$-point, and in the superfluid regime. Previous work has explained the magnitude of this force at the $λ$ transition and deep in the superfluid region but not the substantial attractive force immediately below the $λ$-point. Utilizing a simple mean-field calculation renormalized by critical fluctuations we obtain an effective Casimir force that is qualitatively consistent with the scaling function $\vartheta$ obtained by collapse of experimental data.

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Roya Zandi, Aviva Shackell, Joseph Rudnick, Mehran Kardar, Lincoln Chayes. 2007-03-24. Thinning of superfluid films below the critical point. https://doi.org/10.1103/physreve.76.030601

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