



@article {2562,
	title = {Accelerated Variational Quantum Eigensolver},
	journal = {Phys. Rev. Lett. },
	volume = {122},
	year = {2019},
	month = {3/25/2019},
	abstract = {<p>The problem of finding the ground state energy of a Hamiltonian using a quantum computer is currently solved using either the quantum phase estimation (QPE) or variational quantum eigensolver (VQE) algorithms. For precision ε, QPE requires O(1) repetitions of circuits with depth O(1/ε), whereas each expectation estimation subroutine within VQE requires O(1/ε2) samples from circuits with depth O(1). We propose a generalised VQE algorithm that interpolates between these two regimes via a free parameter α\&isin;[0,1] which can exploit quantum coherence over a circuit depth of O(1/εα) to reduce the number of samples to O(1/ε2(1\&minus;α)). Along the way, we give a new routine for expectation estimation under limited quantum resources that is of independent interest.</p>},
	doi = {https://doi.org/10.1103/PhysRevLett.122.140504},
	url = {https://arxiv.org/abs/1802.00171},
	author = {Daochen Wang and Oscar Higgott and Stephen Brierley}
}
