Researchers from the National University of Singapore (NUS) have successfully simulated higher-order topological (HOT) lattices with unprecedented accuracy using digital quantum computers. These complex lattice structures can assist us understand advanced quantum materials with robust quantum states which might be highly wanted in various technological applications.
The study of topological states of matter and their HOT counterparts has attracted considerable attention amongst physicists and engineers. This fervent interest stems from the invention of topological insulators — materials that conduct electricity only on the surface or edges — while their interiors remain insulating. As a result of the unique mathematical properties of topology, the electrons flowing along the perimeters will not be hampered by any defects or deformations present in the fabric. Hence, devices constituted of such topological materials hold great potential for more robust transport or signal transmission technology.
Using many-body quantum interactions, a team of researchers led by Assistant Professor Lee Ching Hua from the Department of Physics under the NUS Faculty of Science has developed a scalable approach to encode large, high-dimensional HOT lattices representative of actual topological materials into the straightforward spin chains that exist in current-day digital quantum computers. Their approach leverages the exponential amounts of data that may be stored using quantum computer qubits while minimising quantum computing resource requirements in a noise-resistant manner. This breakthrough opens up a brand new direction within the simulation of advanced quantum materials using digital quantum computers, thereby unlocking recent potential in topological material engineering.
The findings from this research have been published within the journal Nature Communications.
Asst Prof Lee said, “Existing breakthrough studies in quantum advantage are limited to highly-specific tailored problems. Finding recent applications for which quantum computers provide unique benefits is the central motivation of our work.”
“Our approach allows us to explore the intricate signatures of topological materials on quantum computers with a level of precision that was previously unattainable, even for hypothetical materials existing in 4 dimensions” added Asst Prof Lee.
Despite the constraints of current noisy intermediate-scale quantum (NISQ) devices, the team is capable of measure topological state dynamics and guarded mid-gap spectra of higher-order topological lattices with unprecedented accuracy because of advanced in-house developed error mitigation techniques. This breakthrough demonstrates the potential of current quantum technology to explore recent frontiers in material engineering. The flexibility to simulate high-dimensional HOT lattices opens recent research directions in quantum materials and topological states, suggesting a possible path to achieving true quantum advantage in the longer term.
