Orbital Optimized ADAPT-VQE for molecular simulation on NISQ devices

Molecular simulation using Variational Quantum Eigensolvers (VQEs) is expected to be a promising application on NISQ devices. Our group's proposed ADAPT-VQE algorithm has shown great promise in this regard as it is quasi-optimally compact in the number of parameters and is expected to be resilient to local minima and barren plateaus. I will present our group's new developments that deal with including orbital relaxation along with iterative ansatz construction in ADAPT-VQE. This can be thought of as a way to classically rotate the orbitals such that the current ansatz captures more correlation energy, ideally speeding the convergence of ADAPT-VQE. I will discuss the benefits of using orbital optimization in VQEs along with the opportunities it presents in simulating molecular ground and excited states on near-term quantum computers.