Experimental demonstration of Robust Amplitude Estimation on near-term
  quantum devices for chemistry applications
This study explores hardware implementation of Robust Amplitude Estimation
(RAE) on IBM quantum devices, demonstrating its application in quantum
chemistry for one- and two-qubit Hamiltonian systems. Known for potentially
offering quadratic speedups over traditional methods in estimating expectation
values, RAE is evaluated under realistic noisy conditions. Our experiments
provide detailed insights into the practical challenges associated with RAE. We
achieved a significant reduction in sampling requirements compared to direct
measurement techniques. In estimating the ground state energy of the hydrogen
molecule, the RAE implementation demonstrated two orders of magnitude better
accuracy for the two-qubit experiments and achieved chemical accuracy. These
findings reveal its potential to enhance computational efficiencies in quantum
chemistry applications despite the inherent limitations posed by hardware
noise. We also found that its performance can be adversely impacted by coherent
error and device stability and does not always correlate with the average gate
error. These results underscore the importance of adapting quantum
computational methods to hardware specifics to realize their full potential in
practical scenarios.
Alexander Kunitsa Nicole Bellonzi Shangjie Guo Jérôme F. Gonthier Corneliu Buda Clena M. Abuan Jhonathan Romero