Executive Summary : | The research aims to develop a compact and expressive ansatz for determining molecular energetics on near-term quantum devices. Current quantum hardware suffers from limited coherence time, poor gate fidelities, and measurement errors, which hinder the execution of deep quantum circuits. A compact ansatz is crucial to leverage the potential of current quantum devices and minimize system interactions with the environment. The successful realization of this compact ansatz relies on the strategic incorporation of general cluster operators or scatterers through commutativity prescreening within the Projective Quantum Eigensolver (PQE) framework. The scatterers can access a larger portion of the Hilbert space and induce higher order excitations through nested commutators. The challenge lies in developing proper theoretical and mathematical machinery to overcome redundancies and determine optimal PQE parameters. Error mitigating techniques, such as zero noise extrapolation, can access accuracies beyond native quantum calculations. The development of novel noise scaling techniques and proper extrapolation methods can facilitate accurate molecular energetic evaluations with practical precision. The development of a compact ansatz for molecular energetics on near-term quantum devices has significant potential for accelerating the discovery and design of new materials and drugs. |