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arXiv · 2609.11811

Block entropy area based non-local fermionic mode optimization with gradient disentanglers

Miklós Antal Werner·Gero Friesecke·Andor Menczer·Kornél Kapás·Örs Legeza
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Abstract

We introduce a systematic block entropy area based mode optimization algorithm for many-body quantum states of interacting fermions represented by matrix product states. From the gradient of a global cost function, the block entropy area, a long-ranged, non-interacting effective disentangler Hamiltonian is formed. We then simulate the time-dependent Schr\"odinger equation driven by the disentangler Hamiltonian by employing the time-dependent variational principle based on projector splitting, and minimize the cost function. The combination of the density matrix renormalization group with this gradient-based entanglement minimization forms an efficient low-rank iterative ground-state algorithm that also provides an optimized single-particle basis for matrix product state representation. We demonstrate the method on two-dimensional lattice models of interacting fermions and the Fe${_4}$S${_4}$ cluster, and show its robustness and superiority over earlier protocols using nearest-neighbor mode rotations and reorderings.

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Miklós Antal Werner, Gero Friesecke, Andor Menczer, Kornél Kapás, Örs Legeza. 2026-09-10. Block entropy area based non-local fermionic mode optimization with gradient disentanglers. https://arxiv.org/abs/2609.11811

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