The Geometry of Qubit Decoherence: Linear vs. Nonlinear Dynamics in the Bloch Ball
Quantum Physics
2025-12-01 v2
Abstract
We present two complementary approaches to the GKSL equation for an open qubit. The first, based on linearity, yields solutions illustrated by mixed states trajectories in the Bloch ball, including non-random asymptotic fixed points, and exceptional points. The second, exploiting the SU(2) symmetry, leads to a nonlinear dynamical system that separates angular dynamics from radial dissipation. This symmetry-based perspective offers a promising route toward generalisation to open qudits.
Cite
@article{arxiv.2510.15726,
title = {The Geometry of Qubit Decoherence: Linear vs. Nonlinear Dynamics in the Bloch Ball},
author = {Alan C. Maioli and Evaldo M. F. Curado and Jean-Pierre Gazeau and Tomoi Koide},
journal= {arXiv preprint arXiv:2510.15726},
year = {2025}
}