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arXiv · 2604.03731

Ground-state selection via nonlinear quantum dissipation

Alireza Ataei·Olle Eriksson·Vahid Azimi Mousolou
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Abstract

Finding the ground state of complex quantum systems remains a central challenge in many-body physics, quantum chemistry, and combinatorial optimization, due to the exponential growth of the Hilbert-space dimension and the entangled structure of ground states. We show that quantum Landau--Lifshitz-Gilbert (QLLG) dynamics, proposed in [Phys. Rev. Lett. 133, 266704 (2024)], provides a physically realizable, real-time nonlinear mechanism that selectively suppresses excited-state components and drives the system toward the lowest-energy eigenstate contained in the initial state. Unlike purely numerical methods such as the imaginary-time projection method, QLLG combines coherent precession with dissipative suppression, enabling experimentally accessible ground-state preparation. For random initial states in the $N$-qubit Hilbert space of dimension $2^N$, convergence occurs in times scaling linearly with system size, $N$, and inversely with the spectral gap. We provide numerical simulations of our analytical results with a Hamiltonian describing an interacting spin chain with Heisenberg exchange and a Zeeman term. Our results identify nonlinear quantum dissipation as a powerful tool for real-time ground-state preparation in large quantum systems and quantum optimization.

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Alireza Ataei, Olle Eriksson, Vahid Azimi Mousolou. 2026-04-04. Ground-state selection via nonlinear quantum dissipation. https://arxiv.org/abs/2604.03731

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