A Method of Determining Excited-States for Quantum Computation

Understand

A method is presented in which the ground-state subspace is projected out of a Hamiltonian representation.

• As a result of this projection, an effective Hamiltonian is constructed where its ground-state coincides with an excited-state of the original problem.
• Thus, low-lying excited-state energies can be calculated using existing hybrid-quantum classical techniques and variational algorithm(s) for determining ground-state.
• The method is shown to be fully valid for the H2 molecule.