ÖPG-CMD Joint Meeting 2026

Electron Correlation Effects on the Electronic Structure and Spin Transport Properties of Spintronic Devices Beyond Linear Response

Sep 21, 2026, 10:30 AM

15m

HS 15.12 (University of Graz)

3) Contributed talk M03 - Correlated Materials Out of Equilibrium Mini-Colloquium

Speaker

Dr Andrea Droghetti (Ca' Foscari University of Venice, Italy)

Description

Two-terminal spintronic devices remain challenging to model under realistic operating conditions, where the interplay of complex electronic structures, correlation effects and bias-driven non-equilibrium dynamics may significantly impact charge and spin transport. Existing ab initio methods either capture bias-dependent transport but neglect dynamical correlations or include correlations but are restricted to equilibrium or linear-response regimes. To overcome these limitations, we present a framework for steady-state quantum transport, combining density functional theory (DFT), the non-equilibrium Greens' function (NEGF) method, and dynamical mean-field theory (DMFT) [1,2,3,4,5]. Our framework is applicable to magnetic heterostructures such as Co/Cu/Co [3,5] and Fe/MgO/Fe [6], as well as magnetic van der Waals materials like Fe₄GeTe₂ [5], allowing for an accurate description of the spectral properties of 3d bands [6]. Furthermore, it can be extended to finite-bias conditions, beyond linear response. Our results reveal that conduction electrons can undergo bias-driven inelastic excitations [7], leading to a regime we term “hot correlated electrons” [8], which produces distinct spectral and transport signatures potentially accessible in operando experiments. More broadly, our findings uncover a general mechanism by which applied voltage reshapes electronic correlations in ferromagnetic materials.

[1] I. Rungger, A. Droghetti, and M. Stamenova, “Non-equilibrium Green’s Function Methods for Spin, Transport and Dynamics”, in Handbook of Materials Modeling: Methods: Theory and Modeling, edited by W. Andreoni and S. Yip (2020).
[2] A. Droghetti, and I. Rungger, Phys. Rev. B 95, 085131(2017).
[3] A. Droghetti, M.M. Radonjić, L. Chioncel, and I. Rungger, Phys. Rev. B 106, 075156 (2022).
[4] A. Droghetti, M.M. Radonjić, A. Halder, I. Rungger, and L. Chioncel, Phys. Rev. B 105, 115129 (2022).
[5] D. Nell, M.M. Radonjic, I., Rungger, L. Chioncel, S. Sanvito, A. Droghetti, arXiv:2511.18442
[6] D. Nell, S. Sanvito, I. Rungger, A. Droghetti, Phys. Rev. B 111, 035133 (2025).
[7] A. Halder, D. Nell, A. Sihi, A. Bajaj, S. Sanvito, and A. Droghetti, Nano Lett. 24, 9221 (2024).
[8] D Nell, S Sanvito, A Droghetti, arXiv:2510.24322