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arXiv · 2405.08499

$Z_{2}$ order fractionalization, topological phase transition, and odd frequency pairing in an exactly solvable spin-charge ladder

Jian-Jian Miao·Wei-Qiang Chen
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Abstract

Motivated by the order fractionalization in Kitaev-Kondo model, we propose an exactly solvable spin-charge ladder model to study the order fractionalization with discrete symmetry. The spin-charge ladder is composed of a spin chain and a superconducting wire coupled via an Ising-type interaction, and we obtain the exact solution in the flat band limit. The exact solution reveals the $Z_{2}$ order fractionalization with dual symmetry breaking and intertwined order parameters. We investigate the topological phase transition of the spin-charge ladder via the spectral chiral index, and identify the correlated topological superconductor (TSC*) phase with gapped $Z_{2}$ Kondo flux excitations. We demonstrate Majorana spinons generated odd frequency pairing in the superconducting wire. We also discuss the order fractionalization in the perspective of $Z_{2}$ lattice gauge theory.

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Jian-Jian Miao, Wei-Qiang Chen. 2024-05-14. $Z_{2}$ order fractionalization, topological phase transition, and odd frequency pairing in an exactly solvable spin-charge ladder. https://arxiv.org/abs/2405.08499

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