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arXiv · 2103.14398

Electric Multipoles of Double Majorana Kramers Pairs

Yuki Yamazaki·Shingo Kobayashi·Ai Yamakage
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Abstract

A single Majorana Kramers pair hosts only one component of the magnetic multipole. This can be used to determine the bulk Cooper-pair symmetry through surface-sensitive spectroscopic measurements, either by applying a magnetic field or by using a ferromagnet/superconductor junction. This paper proposes that the electric response, which is free from the Meissner effect, can be used an alternative method to measure the bulk Cooper-pair symmetry in time-reversal-invariant superconductors with double Majorana Kramers pairs. The relationships among electric multipoles, strain tensors and superconducting symmetries under a given wallpaper group on the surfaces of topological crystalline superconductors are shown. This study also reveals that only a specific irreducible representation of a uniform strain yields a gap in the double Majorana Kramers pairs for the topological-crystalline-superconductor candidate Sr$_3$SnO. This highlights the viability of electric detection regarding Cooper-pair symmetry.

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Yuki Yamazaki, Shingo Kobayashi, Ai Yamakage. 2021-03-26. Electric Multipoles of Double Majorana Kramers Pairs. https://doi.org/10.7566/jpsj.90.073701

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