Quantum simulation of quantum field theory in the light-front formulation*

Quantum field theory is a natural target for simulation on future quantum computers. We will discuss such simulations in the light-front formulation of quantum field theory. This formulation has several appealing features for such simulations foremost of which are its similarities to quantum chemistry where much effort has already been expended in developing and optimizing quantum simulation techiniques. In previous work (2002.04016, 2105.10941), we demonstrated this by developing quantum algorithms based on simulating time evolution and adiabatic state preparation. These algorithms are suitable for future large-scale fault tolerant quantum computers. We also explain how to formulate the relativistic bound state problem as an instance of the Variational Quantum Eigensolver (VQE) algorithm using the Basis Light-Front Quantization (BLFQ) technique (2011.13443, 2009.07885). The BLFQ formulation provides an ideal framework for benchmarking NISQ devices and testing existing algorithms on physically relevant problems such as the calculation of hadronic spectra and parton distribution functions.