Exceptional-point-induced dynamic sensitivity to particle-number parity

J. Y. Liu-Sun; Z. Song

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arXiv · 2509.18563

Exceptional-point-induced dynamic sensitivity to particle-number parity

J. Y. Liu-Sun·Z. Song

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Abstract

As an exclusive feature of a non-Hermitian system, the existence of exceptional points (EPs) depends not only on the details of the Hamiltonian but also on the particle-number filling and the particle statistics. In this paper, we study many-particle EPs in a Bose Hubbard chain with two end-site resonant imaginary potentials. Starting from a single-particle coalescing eigenstate, we construct $n$-particle condensate eigenstates for the cases with zero and infinite $U$. Compared with the free bosonic case, where the $ n $-particle condensate eigenstate is an $(n+1)$-th-order coalescing state, the hardcore-boson counterpart is a second-order coalescing state for odd $n$ , while it is not for even $n$. The difference in particle-number parity results in distinct quenching dynamics of the condensate states, highlighting the role of parity in system behavior. Our finding may stimulate research on the dynamic sensitivity to particle-number parity.

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J. Y. Liu-Sun, Z. Song. 2025-09-23. Exceptional-point-induced dynamic sensitivity to particle-number parity. https://arxiv.org/abs/2509.18563

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