Quantum Filter Diagonalization with Double-Factorized Hamiltonians
- URL: http://arxiv.org/abs/2104.08957v1
- Date: Sun, 18 Apr 2021 21:06:58 GMT
- Title: Quantum Filter Diagonalization with Double-Factorized Hamiltonians
- Authors: Jeffrey Cohn, Mario Motta, Robert M. Parrish
- Abstract summary: We demonstrate a method that merges the quantum filter diagonalization (QFD) approach for hybrid quantum/classical solution of the Schr"odinger equation.
We explore the use of sparse "compressed" double factorization (C-DF) truncation of the Hamiltonian within the time-propagation elements of QFD.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We demonstrate a method that merges the quantum filter diagonalization (QFD)
approach for hybrid quantum/classical solution of the time-independent
electronic Schr\"odinger equation with a low-rank double factorization (DF)
approach for the representation of the electronic Hamiltonian. In particular,
we explore the use of sparse "compressed" double factorization (C-DF)
truncation of the Hamiltonian within the time-propagation elements of QFD,
while retaining a similarly compressed but numerically converged
double-factorized representation of the Hamiltonian for the operator
expectation values needed in the QFD quantum matrix elements. Together with
significant circuit reduction optimizations and number-preserving
post-selection/echo-sequencing error mitigation strategies, the method is found
to provide accurate predictions for low-lying eigenspectra in a number of
representative molecular systems, while requiring reasonably short circuit
depths and modest measurement costs. The method is demonstrated by experiments
on noise-free simulators, decoherence- and shot-noise including simulators, and
real quantum hardware.
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