  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.
