Fermionic mean-field dynamics for spin systems beyond free fermions

• URL: http://arxiv.org/abs/2604.02584v1
• Date: Thu, 02 Apr 2026 23:41:06 GMT
• Title: Fermionic mean-field dynamics for spin systems beyond free fermions
• Abstract summary: fTDHF is a real-time quantum dynamics method for spin-1/2 Hamiltonians.<n>We benchmark fTDHF against exact dynamics on three separate spin-1/2 models.
• Score: 0.09332987715848716
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We introduce the fermionized time-dependent Hartree-Fock (fTDHF), a real-time quantum dynamics method for spin-1/2 Hamiltonians following their mapping to fermions via the Jordan-Wigner transformation. fTDHF is formally equivalent to exact dynamics in the case of free fermions and can efficiently handle non-local string operators arising from long-range interactions via transition matrix elements between non-orthogonal Slater determinants. We show that the fTDHF method can be implemented on a classical computer with a cost that scales polynomially with system size, and linearly with the time steps. We benchmark fTDHF against exact dynamics on three separate spin-1/2 models, representing adiabatic preparation of states with long-range correlations, disorder-driven observation of many-body localization, and particle production in the Schwinger model. For each of these systems, fTDHF is shown to reproduce the qualitative dynamics generated by the exact evolutions, while maintaining a simple physical picture due to its mean-field nature.

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