Lewis Anderson, IBM UK

Computing vacuum states of lattice gauge theories (LGTs) can present significant challenges for classical computation using Monte-Carlo methods. Quantum algorithms may offer a pathway towards more scalable computation of ground state properties of LGTs. However, a comprehensive understanding of the quantum computational resources required for such a problem is thus far lacking. In this work, we investigate using the quantum subspace expansion (QSE) algorithm, implemented via qubitization, applied to the Schwinger model, an archetypal LGT describing quantum electrodynamics in one spatial dimension. We combine analytical resource estimation and numerical simulation to estimate the resource cost required for ground state computation.