D-Wave simulates 3D higher-order topological insulators using 728 qubits

[Deadpool]

D-Wave researchers have used the company's Advantage2 annealing processor to build and measure higher order topological insulators in one, two and three dimensions. Quantum Computing Report's Mohamed Abdel-Kareem reports that the experiments used up to 728 qubits. The work is described in a preprint led by Pratik Sathe and Andrew King

Topological insulators are materials with special properties at their edges, corners or surfaces, which are protected by the material's overall structure. Higher order versions have their special states at corners or hinges rather than along whole surfaces. They are hard to study in real materials, which makes programmable simulators attractive

The team paired physical qubits into strongly coupled dimers that behave like two level systems. They built a 64 qubit chain, a two dimensional quadrupole insulator with corner modes, and a three dimensional octupole insulator on a 3 by 3 by 3 lattice using 432 qubits. Clever time shifted measurements allowed them to reconstruct complex wavefunctions

Using three nested Wilson loops, they extracted a quantised three dimensional octupole moment of one half. The article describes this as the first experimental measurement of its kind. Fractional charges of about one half appeared at the corners, and the results held up against mild hardware disorder

This is a nice example of annealers being used for more than optimisation problems. Programmable quantum simulators could help physicists explore exotic materials before anyone can make them in a lab. It is a preprint, so peer review will be the next step

Are annealers underrated as physics simulators? And which other materials would be worth simulating this way?

D-Wave Demonstrates 3D Analog-Digital Quantum Simulation of Higher-Order Topological Insulators Using 728 Qubits - Quantum Computing Reportquantumcomputingreport.com

[JustMartin]

Pairing qubits into dimers is a neat trick. It turns the hardware into something closer to the model being simulated

Smart engineering. Disorder in real materials often destroys delicate effects

Topological states resist it. That robustness is the whole point