Error mitigating NISQ chemistry computations

Determining whether near-term quantum resources can aid in quantum chemical simulation is an important question for determining the utility of today’s quantum hardware. The work we present here takes steps towards describing the role of NISQ quantum computation in chemical simulation by focusing on the performance of an algorithmic primitive for simulating fermionic systems. Our experiments run on Google’s Sycamore chip achieve chemical accuracy upon application of an error mitigation scheme based on pure-state representability conditions and variational relaxation. Most importantly we describe methods for going beyond this circuit primitive for more correlated model chemistry.