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arXiv · 2603.23011

Local and Global Master Equations through the Lens of Non-Hermitian Physics

Grazia Di Bello·Fabrizio Pavan·Vittorio Cataudella·Donato Farina
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Abstract

We investigate the relation between non-Hermitian Hamiltonian and Lindblad dynamics in nonequilibrium open quantum systems. Non-Hermitian models can extend phase diagrams and enable sensing advantages, but such effects often rely on postselection, raising questions about their relevance for unconditional dynamics. Using a minimal two-qubit setup mediating a heat current, we compare local and global Markovian master equations with their non-Hermitian counterparts. We observe that exceptional points emerge only in the local master equation and in the corresponding non-Hermitian Hamiltonian at sufficiently strong nonequilibrium. We further consider hybrid configurations, where one bath is treated with a Lindblad description and the other with a non-Hermitian approach, interpolating between the two extremes. Our results contribute understanding the role of quantum jumps and exceptional points in nonequilibrium open quantum systems and identify a simple, experimentally accessible architecture, realizable, for instance, in circuit-QED platforms, for their exploration.

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Grazia Di Bello, Fabrizio Pavan, Vittorio Cataudella, Donato Farina. 2026-04-10. Local and Global Master Equations through the Lens of Non-Hermitian Physics. https://arxiv.org/abs/2603.23011

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