Track reconstruction at the LUXE experiment using quantum algorithms

TL;DR

This paper explores the use of quantum algorithms, specifically variational quantum eigensolvers, for reconstructing positron tracks in the LUXE experiment, aiming to improve efficiency at high laser intensities.

Contribution

It presents a novel approach to track reconstruction formulated as a quadratic unconstrained binary optimisation problem solved with quantum algorithms, compared to classical methods.

Findings

Quantum algorithms can reconstruct tracks with comparable accuracy to classical methods.

Different ansatz circuits and optimizers influence the quantum solution quality.

Quantum approaches show potential for high-rate, real-time particle tracking.

Abstract

LUXE (Laser Und XFEL Experiment) is a proposed experiment at DESY which will study Quantum Electrodynamics (QED) in the strong-field regime, where QED becomes non-perturbative. Measuring the rate of created electron-positron pairs using a silicon pixel tracking detector is an essential ingredient to study this regime. Precision tracking of positrons traversing the four layers of the tracking detector becomes very challenging at high laser intensities due to the high rates, which can be computationally expensive for classical computers. In this work, we update our previous study of the potential of using quantum computing to reconstruct positron tracks. The reconstruction task is formulated as a quadratic unconstrained binary optimisation and is solved using simulated quantum computers and a hybrid quantum-classical algorithm, namely the variational quantum eigensolver. Different ansatz circuits and optimisers are studied. The results are discussed and compared with classical track reconstruction algorithms using a graph neural network and a combinatorial Kalman filter.