13–16 Jul 2026
Queen Mary University of London, Mile End Campus
Europe/London timezone

Background electric field effects in (2+1)-QED from digital quantum simulation

14 Jul 2026, 16:50
20m
Maths Lecture Theatre

Maths Lecture Theatre

Building number 4 on the campus map
Contributed Talk Contributed talk

Speaker

James Hancock (University of Plymouth)

Description

I study the effects of a $c$-number background electric field (BEF) on $(2+1)$-dimensional QED in the staggered Hamiltonian formulation - a setting in which the standard Euclidean Monte Carlo approach suffers from a sign problem, but which remains accessible to Hamiltonian quantum simulation. After digitizing the gauge and fermionic degrees of freedom onto qubits (Gray-encoded links, Jordan-Wigner fermions) and reducing to the physical Hilbert space via Gauss' law, I prepare the groundstate using a gauge-invariant VQE built from symmetry-preserving quantum circuits. Running on realistic hardware noise models with a combination of QEM techniques (measurement error mitigation, symmetry verification, and zero-noise extrapolation), I examine three features: the BEF-induced screening phase structure (reminiscent of the Schwinger model), the change in the static-charge string tension and confinement, and - more preliminarily - the effect on chiral symmetry breaking. I discuss how the digitization scales with lattice size and gauge-field truncation, and argue that this approach offers a practical route to background-field physics in gauge theories that are otherwise obstructed by a sign problem.

Author

James Hancock (University of Plymouth)

Co-authors

Dr Craig McNeile (Plymouth University) Dr Davide Vadacchino (University of Plymouth) Dr Matthew Craven (University of Plymouth)

Presentation materials