Orbital Angular Momentum Textures and Currents in a Discrete Helix: Equilibrium and Linear Response

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Hauptverfasser: Cordova, Danny, Berche, Bertrand, Medina, Ernesto
Format: Preprint
Veröffentlicht: 2026
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author Cordova, Danny
Berche, Bertrand
Medina, Ernesto
author_facet Cordova, Danny
Berche, Bertrand
Medina, Ernesto
contents Recently, nonequilibrium orbital angular momentum in low-dimensional systems has attracted renewed attention. Here we introduce a minimal three-orbital tight-binding model for a single helical chain and show that chirality alone generates a momentum-dependent orbital-angular-momentum texture through Slater--Koster hybridization in the local basis $(p_r,p_ϕ,p_z)$, without requiring atomic spin--orbit coupling. In the single-helix geometry, the radial orbital texture vanishes identically, while the azimuthal and longitudinal components remain finite and arise from the odd-in-momentum $(p_z,p_r)$ and $(p_r,p_ϕ)$ sectors. As a result, the equilibrium average orbital texture vanishes by parity, although persistent-like orbital angular momentum currents may still exist and imply chirality-dependent end magnetization in a finite helix. Under an applied longitudinal electric field, the system develops a finite orbital Edelstein response, whereas the projected longitudinal orbital-current conductivity vanishes in the linear regime by parity. When spin degrees of freedom are included, the orbital texture acts as a source of spin polarization through orbital-to-spin transduction. The resulting spin response is controlled by orbital overlap scales much larger than the bare relativistic spin--orbit scale, making it a stronger candidate for spin injection than the conventional spin Edelstein mechanism. These results identify chirality as the minimal microscopic ingredient for generating orbital angular momentum response in one-dimensional systems and support an orbital route to spin selectivity in chiral conductors.
format Preprint
id arxiv_https___arxiv_org_abs_2605_15981
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Orbital Angular Momentum Textures and Currents in a Discrete Helix: Equilibrium and Linear Response
Cordova, Danny
Berche, Bertrand
Medina, Ernesto
Mesoscale and Nanoscale Physics
Recently, nonequilibrium orbital angular momentum in low-dimensional systems has attracted renewed attention. Here we introduce a minimal three-orbital tight-binding model for a single helical chain and show that chirality alone generates a momentum-dependent orbital-angular-momentum texture through Slater--Koster hybridization in the local basis $(p_r,p_ϕ,p_z)$, without requiring atomic spin--orbit coupling. In the single-helix geometry, the radial orbital texture vanishes identically, while the azimuthal and longitudinal components remain finite and arise from the odd-in-momentum $(p_z,p_r)$ and $(p_r,p_ϕ)$ sectors. As a result, the equilibrium average orbital texture vanishes by parity, although persistent-like orbital angular momentum currents may still exist and imply chirality-dependent end magnetization in a finite helix. Under an applied longitudinal electric field, the system develops a finite orbital Edelstein response, whereas the projected longitudinal orbital-current conductivity vanishes in the linear regime by parity. When spin degrees of freedom are included, the orbital texture acts as a source of spin polarization through orbital-to-spin transduction. The resulting spin response is controlled by orbital overlap scales much larger than the bare relativistic spin--orbit scale, making it a stronger candidate for spin injection than the conventional spin Edelstein mechanism. These results identify chirality as the minimal microscopic ingredient for generating orbital angular momentum response in one-dimensional systems and support an orbital route to spin selectivity in chiral conductors.
title Orbital Angular Momentum Textures and Currents in a Discrete Helix: Equilibrium and Linear Response
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2605.15981