Pair density wave in the fractional quantum Hall effect at even denominator

M. V. Milovanović

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arXiv · 2511.19567

Pair density wave in the fractional quantum Hall effect at even denominator

M. V. Milovanović

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Abstract

The fractional quantum Hall effect (FQHE) at filling 5/2, which is usually understood as a $p$-wave paired state of underlying quasiparticles - composite fermions, transforms into a nematic phase under pressure \cite{csathy0, csathy}. A pair density wave (PDW) may be a precursor, underlying state for this behaviour, and such state(s) were proposed that maintain the weak-pairing feature of the uniform paired state \cite{frad}. Based on considerations in the weak-coupling regime of a microscopic description of the pairing phase (to mimic the phase as it gives way to a nematic phase in the experiments), we argue that the ensuing and relevant PDW state has a strong-pairing character. Furthermore, due to the existence of a single collective mode associated with the order parameter in the uniform paired phase, in the weak-coupling regime, the $p$-wave paired state, in general (for example, in the superconducting state of electrons), may be prone to a PDW instability.

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M. V. Milovanović. 2025-11-24. Pair density wave in the fractional quantum Hall effect at even denominator. https://arxiv.org/abs/2511.19567

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