TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhys.20.2.035
TI  - Electron charge dynamics and charge separation: A response theory approach
PY  - 2026/02/09
UR  - https://scipost.org/SciPostPhys.20.2.035
JF  - SciPost Physics
JA  - SciPost Phys.
VL  - 20
IS  - 2
SP  - 035
A1  - Lacombe, Lionel
AU  - Reining, Lucia
AU  - Gorelov, Vitaly
AB  - This study applies response theory to investigate electron charge dynamics, with a particular focus on charge separation. We analytically assess the strengths and limitations of linear and quadratic response theories in describing charge density and current, illustrated by a model that simulates charge transfer systems. While linear response accurately captures optical properties, the quadratic response contains the minimal ingredients required to describe charge dynamics and separation. Notably, it closely matches exact time propagation results in some regime that we identify. We propose and test several approximations to the quadratic response and explore the influence of higher-order terms and the effect of on-site and nearest-neighbour interactions $U$ and $V$.
ER  -

@Article{10.21468/SciPostPhys.20.2.035,
	title={{Electron charge dynamics and charge separation: A response theory approach}},
	author={Lionel Lacombe and Lucia Reining and Vitaly Gorelov},
	journal={SciPost Phys.},
	volume={20},
	pages={035},
	year={2026},
	publisher={SciPost},
	doi={10.21468/SciPostPhys.20.2.035},
	url={https://scipost.org/10.21468/SciPostPhys.20.2.035},
}