Randomizing multi-product formulas for Hamiltonian simulation

Faehrmann PK, Steudtner M, Kueng R, Kieferova M, Eisert J (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Quantum Verein zur Förderung des Open Access Publizierens in den Quantenwissenschaften e-V-

Book Volume: 6

Article Number: 806

DOI: 10.22331/Q-2022-09-19-806

Abstract

Quantum simulation, the simulation of quantum processes on quantum computers, suggests a path forward for the efficient simulation of problems in condensed-matter physics, quantum chemistry, and materials science. While the majority of quantum simulation algorithms are deterministic, a recent surge of ideas has shown that randomization can greatly benefit algorithmic performance. In this work, we introduce a scheme for quantum simulation that unites the advantages of randomized compiling on the one hand and higher-order multiproduct formulas, as they are used for example in linear-combination-of-unitaries (LCU) algorithms or quantum error mitigation, on the other hand. In doing so, we propose a framework of randomized sampling that is expected to be useful for programmable quantum simulators and present two new multi-product formula algorithms tailored to it. Our framework reduces the circuit depth by circumventing the need for oblivious amplitude amplification required by the implementation of multi-product formulas using standard LCU methods, rendering it especially useful for early quantum computers used to estimate the dynamics of quantum systems instead of performing full-fledged quantum phase estimation. Our algorithms achieve a simulation error that shrinks exponentially with the circuit depth. To corroborate their functioning, we prove rigorous performance bounds as well as the concentration of the randomized sampling procedure. We demonstrate the functioning of the approach for several physically meaningful examples of Hamiltonians, including fermionic systems and the Sachdev–Ye–Kitaev model, for which the method provides a favorable scaling in the effort.

Involved external institutions

Freie Universität Berlin DE Germany (DE) Johannes Kepler Universität (JKU) Linz AT Austria (AT) University of Technology Sydney (UTS) AU Australia (AU)

How to cite

APA:

Faehrmann, P.K., Steudtner, M., Kueng, R., Kieferova, M., & Eisert, J. (2022). Randomizing multi-product formulas for Hamiltonian simulation. Quantum, 6. https://doi.org/10.22331/Q-2022-09-19-806

MLA:

Faehrmann, Paul K., et al. "Randomizing multi-product formulas for Hamiltonian simulation." Quantum 6 (2022).

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