Importance of the Spectral gap in Estimating Ground-State Energies
Abhinav Deshpande, Alexey Vyacheslavovich Gorshkov, Bill Fefferman · PRX Quantum · 2022
The circuit complexity in preparing the ground state of a Hamiltonian is studied as a function of the spectral gap---the energy difference between the ground and the first excited state---and an optimistic outlook for quantum variational methods is presented.