publication . Preprint . 2020

Tailoring Term Truncations for Electronic Structure Calculations Using a Linear Combination of Unitaries

Meister, Richard; Benjamin, Simon C.; Campbell, Earl T.;
Open Access English
  • Published: 22 Jul 2020
Abstract
A highly anticipated use of quantum computers is the simulation of complex quantum systems including molecules and other many-body systems. One promising method involves directly applying a linear combination of unitaries (LCU) to approximate a Taylor series by truncating after some order. Here we present an adaptation of that method, optimized for Hamiltonians with terms of widely varying magnitude, as is commonly the case in electronic structure calculations. We show that it is more efficient to apply LCU using a truncation that retains larger magnitude terms as determined by an iterative procedure. We obtain bounds on the simulation error for this generalized...
Subjects
free text keywords: Quantum Physics
Funded by
UKRI| Towards fault-tolerant quantum computing with minimal resources.
Project
  • Funder: UK Research and Innovation (UKRI)
  • Project Code: EP/M024261/1
  • Funding stream: EPSRC
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