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arXiv · 1202.5027

The Superconducting Phases of URu2Si2: Longitudinal Sound Velocity Measurements

B. S. Shivaram·V. W. Ulrich·D. G. Hinks
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Abstract

High resolution longitudinal sound velocity measurements in a magnetic field performed in the temperature tending to zero limit reveal two distinct signatures attributable to multiple superconducting phases in URu2Si2. A step change in the sound velocity, for propagation in the basal plane, is observed at the critical field, Bc2. This step broadens considerably as T tends to Tc with a concomitant decrease in magnitude. A second step is observed at a field ~0.5 Bc2 and it's magnitude remains constant at all temperatures. Inductive measurements of the transitions in a magnetic field, however, exhibit a single signature which coincides with the lower step with no discernible in-phase signature at the upper transition. Measurements performed with B oriented at various angles between the a and c-axes reveal a weaker angular dependence of the lower step and confirm the rapid fall off of Bc2 close to B||c-axis. An off axis superconducting phase diagram is proposed.

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B. S. Shivaram, V. W. Ulrich, D. G. Hinks. 2012-02-22. The Superconducting Phases of URu2Si2: Longitudinal Sound Velocity Measurements. https://arxiv.org/abs/1202.5027

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