The team, led by Mikhail Lukin, the Joshua and Beth Friedman University Professor in physics and co-director of the Harvard Quantum Initiative, has created the first programmable, logical quantum processor, capable of encoding up to 48 logical qubits, and executing hundreds of logical gate operations, a vast improvement over prior efforts. In quantum computing, a quantum bit or “qubit” is one unit of information, just like a binary bit in classical computing. The real coins of the realm are so-called logical qubits: bundles of redundant, error-corrected physical qubits, which can store information for use in a quantum algorithm. The Harvard team’s breakthrough builds on several years of work on a quantum computing architecture known as a neutral atom array, pioneered in Lukin’s lab. With their logical quantum processor, the researchers now demonstrate parallel, multiplexed control of an entire patch of logical qubits, using lasers.
