Measuring the Renyi entropy of a two-site Fermi-Hubbard model on a trapped ion quantum computer

TL;DR

This paper demonstrates measuring the second Renyi entropy of a two-site Fermi-Hubbard model's ground state using a trapped ion quantum computer, showcasing a scalable method for entanglement measurement in quantum systems.

Contribution

It introduces a method to measure the second Renyi entropy on a small quantum computer, enabling insights into many-body quantum systems beyond classical simulation capabilities.

Findings

Successful measurement of Renyi entropy on a 5-qubit system

Implementation of controlled-swap gate for entanglement extraction

Scalable approach for studying quantum many-body systems

Abstract

The efficient simulation of correlated quantum systems is the most promising near-term application of quantum computers. Here, we present a measurement of the second Renyi entropy of the ground state of the two-site Fermi-Hubbard model on a $5$-qubit programmable quantum computer based on trapped ions. Our work illustrates the extraction of a non-linear characteristic of a quantum state using a controlled-swap gate acting on two copies of the state. This scalable measurement of entanglement on a universal quantum computer will, with more qubits, provide insights into many-body quantum systems that are impossible to simulate on classical computers.