TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhysCore.9.1.002
TI  - Majorana diagrammatics for quantum spin-1/2 models
PY  - 2026/01/16
UR  - https://scipost.org/SciPostPhysCore.9.1.002
JF  - SciPost Physics Core
JA  - SciPost Phys. Core
VL  - 9
IS  - 1
SP  - 002
A1  - Noblet, Thibault
AU  - Messio, Laura
AU  - Rossi, Riccardo
AB  - A diagrammatic formalism for lattices of 1/2 is developed. It is based on an unconstrained mapping between spin and Majorana operators. This allows the use of standard tools of diagrammatic quantum many-body theory without requiring projections. We derive, in particular, the Feynman rules for the expansion around a color-preserving mean-field theory. We then present the numerical results obtained by computing the corrections up to second order for the Heisenberg model in one and two dimensions, showing that perturbative corrections are not only numerically important, but also qualitatively improve the results of mean-field theory. These results pave the way for the use of Majorana diagrammatic tools in theoretical and numerical studies of quantum spin systems.
ER  -

@Article{10.21468/SciPostPhysCore.9.1.002,
	title={{Majorana diagrammatics for quantum spin-1/2 models}},
	author={Thibault Noblet and Laura Messio and Riccardo Rossi},
	journal={SciPost Phys. Core},
	volume={9},
	pages={002},
	year={2026},
	publisher={SciPost},
	doi={10.21468/SciPostPhysCore.9.1.002},
	url={https://scipost.org/10.21468/SciPostPhysCore.9.1.002},
}