  We present a hybrid classical/quantum algorithm for efficiently solving the
eigenvalue problem of many-particle Hamiltonians on quantum computers with
limited resources by splitting the workload between classical and quantum
processors. This algorithm reduces the needed number of qubits at the expense
of an increased number of quantum evaluations. We demonstrate the method for
the Hubbard model and show how the conservation of the z-component of the total
spin allows the spin-up and spin-down configurations to be computed on
classical and quantum hardware, respectively. Other symmetries can be exploited
in a similar manner.
