What if ultrafast pulses of light could operate computers at speeds a million times faster than today’s best processors? A team of scientists, including researchers from the University of Arizona, are working to make that possible.

In an international effort, researchers from the Department of Physics in the College of Science and the James C. Wyant College of Optical Sciences have demonstrated a way to manipulate electrons in graphene using pulses of light that last less than a trillionth of a second. By leveraging a quantum effect known as tunneling, they recorded electrons bypassing a physical barrier almost instantaneously, a feat that redefines the potential limits of computer processing power.

A study published in Nature Communications highlights how the technique could lead to processing speeds in the petahertz range—over 1,000 times faster than modern computer chips.

In the world of quantum computing, the Hilbert space dimension—the measure of the number of quantum states that a quantum computer can access—is a prized possession. Having a larger Hilbert space allows for more complex quantum operations and plays a crucial role in enabling quantum error correction (QEC), essential for protecting quantum information from noise and errors.

A recent study by researchers from Yale University published in Nature created qudits—a quantum system that holds quantum information and can exist in more than two states. Using a qutrit (3-level quantum system) and a ququart (4-level quantum system), the researchers demonstrated the first-ever experimental quantum error correction for higher-dimensional quantum units using the Gottesman–Kitaev–Preskill (GKP) bosonic code.

Most quantum computers on the market usually process information using quantum states called qubits—fundamental units similar to a bit in a regular computer that can exist in two well-defined states, up and down and also both 0 and 1 at the same time, due to quantum superposition. The Hilbert space of a single qubit is a two-dimensional complex vector space.