Algorithm Breakthrough Paves the Way for More Advanced Quantum Computing


Trying to study a large quantum system on a normal computer gets very time-consuming very quickly because the physics is so complex. In 1982, physicist Richard Feynman predicted that it would be much easier to study quantum systems on, correspondingly, a quantum computer. As it turns out, he was right.

In a new study, researchers present an algorithm that will let scientists study a many-body quantum state on a quantum computer. Professor Pouyan Ghaemi of City College of New York and The Graduate Center was an author on the study, which appears in the journal PRX Quantum.

Quantum physics is the study of how matter acts at the tiniest scale—think electrons, the negatively-charged particles that orbit an atom’s nucleus. Quantum behavior differs substantially from the behavior of big, everyday objects, but at the same time, it “leads to formation of molecules and the resulting matter around us,” as Ghaemi told CCNY.

The researchers were looking for a way to study a quantum phenomenon called the fractional quantum Hall effect. Examining this effect in solid-state materials is challenging, so the next best option is to simulate it on a computer. On a “classical” computer this can take an exceedingly long time, and the time quickly gets longer and longer for larger systems. Fortunately, advancements in quantum computing are giving researchers a new way to do things.

Ghaemi and colleagues presented a highly efficient algorithm that can generate a fractional quantum Hall state on a digitized quantum computer.

“Our algorithm opens a new venue to use the new quantum devices to study problems which are quite challenging to study using classical computers,” Ghaemi told CCNY. “Our results are new and motivate many follow up studies.”