TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhys.15.4.137
TI  - Weak vs. strong breaking of integrability in interacting scalar quantum field theories
PY  - 2023/10/05
UR  - https://scipost.org/SciPostPhys.15.4.137
JF  - SciPost Physics
JA  - SciPost Phys.
VL  - 15
IS  - 4
SP  - 137
A1  - Fitos, Bence
AU  - Takács, Gábor
AB  - The recently proposed classification of integrability-breaking perturbations according to their strength is studied in the context of quantum field theories. Using random matrix methods to diagnose the resulting quantum chaotic behaviour, we investigate the $\phi^4$ and $\phi^6$ interactions of a massive scalar, by considering the crossover between Poissonian and Wigner-Dyson distributions in systems truncated to a finite-dimensional Hilbert space. We find that a naive extension of the scaling of crossover coupling with the volume observed in spin chains does not give satisfactory results for quantum field theory. Instead, we demonstrate that considering the scaling of the crossover coupling with the number of particles yields robust signatures, and is able to distinguish between the strengths of integrability breaking in the $\phi^4$ and $\phi^6$ quantum field theories.
ER  -

@Article{10.21468/SciPostPhys.15.4.137,
	title={{Weak vs. strong breaking of integrability in interacting scalar quantum field theories}},
	author={Bence Fitos and Gábor Takács},
	journal={SciPost Phys.},
	volume={15},
	pages={137},
	year={2023},
	publisher={SciPost},
	doi={10.21468/SciPostPhys.15.4.137},
	url={https://scipost.org/10.21468/SciPostPhys.15.4.137},
}