Nonequilibrium Dirac condensate in bosonic Kitaev chain

Kazuki Yamamoto; Youichi Yanase

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arXiv · 2609.29082

Nonequilibrium Dirac condensate in bosonic Kitaev chain

Kazuki Yamamoto·Youichi Yanase

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Abstract

We explore a nonequilibrium Bose-Einstein condensate (BEC) in a bosonic Kitaev chain. Within a mean-field framework, we show that bosonic superfluid order develops once the pairing strength exceeds a critical threshold. The condensate order parameter adopts an alternating phase between even and odd sites, giving rise to a spontaneous sublattice ordering. By mapping the emergent sublattice degrees of freedom onto a pseudospin, the elementary Bogoliubov excitation is described by a non-Hermitian Dirac Hamiltonian, displaying two prominent features: a re-entrant bosonic Andreev bound state localized around boundaries, and a macroscopic degeneracy of exceptional Majorana bosons at the critical point.

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Kazuki Yamamoto, Youichi Yanase. 2026-09-24. Nonequilibrium Dirac condensate in bosonic Kitaev chain. https://arxiv.org/abs/2609.29082

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