Breakdown of the Meissner effect at the zero exceptional point in non-Hermitian two-band BCS model

Takano Taira

doi:10.1088/1751-8121/ad1d23

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arXiv · 2211.11422

Breakdown of the Meissner effect at the zero exceptional point in non-Hermitian two-band BCS model

Takano Taira

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Abstract

The spontaneous symmetry breaking of a continuous symmetry in complex field theory at the exceptional point of the parameter space is known to exhibit interesting phenomena, such as the breakdown of a Higgs mechanism. In this work, we derive the complex Ginzburg-Landau model from a non-Hermitian two-band BCS model via path integral and investigate its spontaneous symmetry breaking. We find that analog to the Higgs mechanism, the Meissner effect of the complex Ginzburg-Landau model also breaks down at the exceptional point while the gap parameters stay finite.

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Takano Taira. 2022-11-21. Breakdown of the Meissner effect at the zero exceptional point in non-Hermitian two-band BCS model. https://doi.org/10.1088/1751-8121%2Fad1d23

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