  We develop a novel, systematic input scheme for many-boson Hamiltonians in
order to solve field theory problems within the light-front Hamiltonian
formalism via quantum computing. We present our discussion of this input scheme
based on the light-front Hamiltonian of the two-dimensional $\phi ^4$ theory.
In our input scheme, we employ a set of quantum registers, where each register
encodes the occupation of a distinct boson mode as binaries. We squeeze the
boson operators of each mode and present the Hamiltonian in terms of unique
combinations of the squeezed boson operators. We design the circuit modules for
these unique combinations. Based on these circuit modules, we block encode the
many-boson Hamiltonian utilizing the idea of quantum walk. We demonstrate our
input scheme by solving the low-lying spectra of the Hamiltonian utilizing the
IBM Qiskit quantum simulator. We can incorporate the input scheme in this work
with the input scheme for many-fermion Hamiltonians; they jointly offer new
pathways to solving the structure and dynamics of field theory problems on
future fault-tolerant quantum computers.
