Entanglement spectrum ordering and flavor polarization in the two-flavor Schwinger model at vacuum angle $\theta = \pi$

Abstract:Entanglement spectra in gauge theories can encode both symmetry breaking and the organization of gauge sectors. In the two-flavor Schwinger model at vacuum angle $\theta=\pi$, we find that the joint Schmidt distribution $p_{Q_A,F_A}$, labeled by the subsystem gauge charge $Q_A$ and flavor imbalance $F_A$, reveals a cut-dependent gauge-sector hierarchy and a mass-induced flavor asymmetry: changing the staggered cut reorganizes the gauge-charge distribution $p_{Q_A}$, while mass imbalance breaks the $F_A\leftrightarrow-F_A$ symmetry of the conditional flavor distribution $p_{F_A|Q_A}$. Defining the combined weight $W_F^{(q)}=p_{q,+1}+p_{q,-1}$ and conditional polarization $\mathcal P_F^{(q)}=(p_{q,+1}-p_{q,-1})/W_F^{(q)}$, we find that changing the cut reverses the weight hierarchy, $W_F^{(-1)}>W_F^{(+1)}$ at unit-cell boundaries but $W_F^{(+1)}>W_F^{(-1)}$ at intra-cell cuts, while mass imbalance drives $\mathcal P_F^{(q)}$ away from zero with a $q$-dependent cut response. Symmetry resolution therefore separates gauge-sector ordering, sector weight, and flavor polarization that are mixed in the globally ordered entanglement spectrum.

21 pages, 6 figures. Submitted to $\textit{Chinese Physics C}$

High Energy Physics - Lattice (hep-lat); Statistical Mechanics (cond-mat.stat-mech); Quantum Physics (quant-ph)

arXiv:2608.14296 [hep-lat]

(or arXiv:2608.14296v1 [hep-lat] for this version)

https://doi.org/10.48550/arXiv.2608.14296 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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