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arXiv:2511.09714 · Journal of High Energy Physics

Geometry Induced Chiral Transport and Entanglement in $AdS_2$ Background

Kazuki Ikeda, Yaron Oz

hep-thcond-mat.mes-hallhep-phnucl-thquant-phSubmitted Nov 12, 2025• Announced Nov 14, 2025• 2 citations• Revised Feb 17, 2026 (v3)
v1 · Nov 12, 2025v2 · Nov 23, 2025v3 · Feb 17, 2026
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Abstract

We study the real-time chiral dynamics of Dirac fermions in AdS$_2$ and AdS$_2$ black hole backgrounds. The spacetime curvature generates a spin connection term, acting as an effective magnetic field and a position-dependent chiral chemical potential. This leads to strongly asymmetric wave propagation, confined within an inhomogeneous Lieb-Robinson cone. The front velocities decrease with increasing fermion mass and horizon radius. The entanglement entropy grows inside the causal cone, and it saturates due to screening/dephasing in the finite inhomogeneous chain. In dipole-dipole collision, the central bipartite entropy rises when the inward Lieb-Robinson fronts intersect, forming a bright ridge in the local entanglement profile. Charge and current correlators peak at the front arrival, providing a real-time diagnostic of chiral transport. These results establish a causality-respecting framework, linking curvature and horizons to transport and entanglement in (1+1)-dimensional fermionic matter.

Journal reference
J. High Energ. Phys. 2026, 177 (2026)
DOI
10.1007/JHEP04(2026)177
Comments
25 pages, 10 figures

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We study the effect of charged excitations in the AdS spacetime on the first law of entanglement thermodynamics. It is found that `boosted' AdS black holes give rise to a more general form of first law which includes chemical potential and charge density. To obtain this result we have to resort to a second order perturbative calculation of entanglement entropy for small size subsystems. At first order the form of entanglement law remains unchanged even in the presence of charged excitations. But the thermodynamic quantities have to be appropriately `renormalized' at the second order due to the corrections. We work in the perturbative regime where Tthermal≪TET_{thermal}\ll T_ETthermal​≪TE​.
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