Simulating quantum field theory in the light-front formulation*

We explore the possibility of simulating relativistic field theories in the light-front (LF) formulation and argue that such a framework has numerous advantages as compared to both lattice and second-quantized equal-time approaches. These include a small number of physical degrees of freedom leading to reduced resource requirements, efficient encoding with model-independent asymptotics, and sparse Hamiltonians. Many quantities of physical interest are naturally defined in the LF, resulting in simple measurements.

The LF formulation allows one to trace the connection between relativistic field theories and quantum chemistry, allowing one to use numerous techniques developed in the last decade. It also provides a promising application for NISQ devices, since for certain calculations one may need of an order of hundred qubits. As an example, we provide a detailed algorithm for calculating analogues of QCD parton distribution functions in a simple 1+1-dimensional model. We also discuss the generalization to QCD, and provide estimates.