Measurement of the entanglement spectrum of a symmetry-protected topological state using the IBM quantum computer

TL;DR

This paper demonstrates the first experimental measurement of the entanglement spectrum of a symmetry-protected topological state using IBM quantum computers, distinguishing it from trivial and ordered states.

Contribution

It introduces a novel experimental approach to measure the entanglement spectrum of topological states on a quantum computer.

Findings

Successfully measured the entanglement spectrum of a topological state.

Differentiated the entanglement spectrum from trivial and ordered states.

Showed feasibility of quantum computers for complex quantum measurements.

Abstract

Entanglement properties are routinely used to characterize phases of quantum matter in theoretical computations. For example the spectrum of the reduced density matrix, or so-called "entanglement spectrum", has become a widely used diagnostic for universal topological properties of quantum phases. However, while being convenient to calculate theoretically, it is notoriously hard to measure in experiments. Here we use the IBM quantum computer to make the first ever measurement of the entanglement spectrum of a symmetry-protected topological state. We are able to distinguish its entanglement spectrum from those we measure for trivial and long-range ordered states.