Experimental Performance of a Quantum Simulator: Optimizing Adiabatic Evolution and Identifying Many-Body Ground States

TL;DR

This paper demonstrates an experimental approach using local adiabatic evolution to efficiently prepare and identify ground states in a fully-connected Ising model with up to 14 spins, improving ground state probability.

Contribution

It introduces the use of local adiabatic evolution for experimental ground state preparation and identification in many-body quantum systems, requiring only partial spectral knowledge.

Findings

Local adiabatic evolution maximizes ground state probability.

Ground state ordering can be identified from configuration probabilities.

Method effective even with highly non-adiabatic evolution.

Abstract

We use local adiabatic evolution to experimentally create and determine the ground state spin ordering of a fully-connected Ising model with up to 14 spins. Local adiabatic evolution -- in which the system evolution rate is a function of the instantaneous energy gap -- is found to maximize the ground state probability compared with other adiabatic methods while only requiring knowledge of the lowest $\sim N$ of the $2^N$ Hamiltonian eigenvalues. We also demonstrate that the ground state ordering can be experimentally identified as the most probable of all possible spin configurations, even when the evolution is highly non-adiabatic.