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arXiv · 0911.1599

Roton energy gap and spontaneous symmetry breaking

Junpei Harada
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Abstract

We study elementary excitations in superfluid helium-4 employing an approach based on the spontaneous symmetry breaking. In particular, we calculate the roton energy gap at zero temperature $\Delta (0)$. The relation that we have derived is $\Delta (0) / k_B T_\lambda = 4$. The theoretical value of $\Delta (0)/k_B$ is 8.707 K, which is significantly close to the experimental value of 8.712 K. The deviation between the theoretical and experimental values is less than 0.1%.

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Junpei Harada. 2009-11-09. Roton energy gap and spontaneous symmetry breaking. https://arxiv.org/abs/0911.1599

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