Non-local nonstabiliserness in Gluon and Graviton Scattering

TL;DR

This paper investigates the non-local non-stabiliserness, or 'magic', in gluon and graviton scattering, revealing how it varies with initial states and basis choices, and its sensitivity to new physics beyond the Standard Model.

Contribution

It derives the basis-independent non-local non-stabiliserness measure for gluon and graviton scattering, linking it to the helicity basis and exploring effects of additional operators.

Findings

Helicity basis often coincides with basis of manifest non-local magic.

Adding new operators to the Yang-Mills Lagrangian breaks this property.

Results provide insight into quantum information aspects of particle scattering.

Abstract

The property of non-stabiliserness, or ``magic'', is of interest in quantum computing due to its role in developing fault-tolerant quantum algorithms with genuine computational advantage over classical counterparts. There has been much interest in quantifying magic in various physical systems, in order to probe how to produce and enhance it. The production of magic has previously been quantified in gluon and graviton scattering, in the so-called helicity basis relating particle spins with momentum directions. For a basis-independent statement, one should instead use the recently developed concept of non-local non-stabiliserness, and our aim in this paper is to derive how this varies for gluon and graviton scattering processes. Our results show that, for many initial states, including those produced with polarised beams, the helicity basis coincides with a basis in which the non-local magic is manifest, providing a physical motivation for using the helicity basis to study quantum information quantities. However, this property breaks upon adding additional operators to the Yang-Mills Lagrangian, as would be the case in new physics scenarios.