Yumin Hu

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The Lindblad master equation provides a fundamental framework for describing
open quantum many-body systems coupled to a Markovian environment. Dissipative
couplings not only enable the preparation and control of novel quantum states but also lead
to nonequilibrium phases without Hermitian counterparts. In this talk, I will present our two
recent developments in this direction. In the first part, I will introduce the notion of asymptotic
exceptional steady states in dissipative dynamics [1]. Although exceptional points are
forbidden for exact degenerate steady states of Liouvillians, a large class of open many-body
systems can asymptotically approach an exceptional steady state as the system size increases.
Such an asymptotic structure has an intriguing connection to the computational complexity
of dissipative state preparation. In the second part, I will discuss a dissipative quantum link
model that naturally exhibits a many-body non-Hermitian skin effect — an anomalous
boundary localization phenomenon [2]. Despite the complexity arising from strong
interactions, local gauge symmetry enables the exact construction of steady states. We also
propose a hierarchical skin effect, where different subsystems exhibit boundary accumulation
of multipole moments of different orders. These results demonstrate how dissipation can be
used in quantum many-body experiments to engineer unexpected steady states.
[1] Y.-M. Hu and J. C. Budich, Phys. Rev. Lett. 135, 250402 (2025).
[2] Y.-M. Hu, Z. Wang, B. Lian, and Z. Wang. Phys. Rev. Lett. 135, 260401 (2025).

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Max Planck Institute for the Physics of Complex Systems, Dresden
0.03
Contact: Bo Han