Researchers at DARPA (yes—the same folks who brought you the Internet in 1969, or actually the Internet’s ancestor, ARPANET) have just announced a major breakthrough in quantum computing, creating the first-ever quantum circuit with logical quantum bits (qubits). Logical qubits (as opposed to error-prone physical qubits) maintain their quantum state, which makes them more useful for solving diverse sets of complex problems. These new quibits—so-called Rydberg qubits—are also identical, which allows them to be scaled and manipulated easily.
The Rydberg logical qubit breakthrough revolutionizes previous thinking that millions of physical qubits will be needed needed before a quantum computer can be created. Using logical quibits, this number has now become significantly smaller (by how much isn’t currently known). Current quantum computing chips create lots of errors, and workarounds have been developed for these. Even with these errors, however, a quantum computer with only a hundred or so qubits can produce accurate results many times faster than the world’s most powerful supercomputer, and is also billions of times more capable, able to analyze vastly more complex problems. This capability is intriguing for scientists looking to tease discoveries out of the huge datasets that exist in every field, from astrophysics to genetics to neuroscience, pharmacology, and beyond. The DARPA machine described in this news release contained 48 logical qubits.
The research programs run by DARPA—which stands for the Defense Advanced Research Projects Agency (housed inthe US Department of Defense)— have always been at the cutting edge of innovation and technology. The agency’s work on quantum programs, dating back to the early 2000s, has focused on building bridges between the quantum sensing and quantum information science research communities, which have traditionally been siloed. In this case, this bridge—this more effective communication inside science (see also: the mission of the Science Communication Institute)—brought together research teams that don’t normally speak to each other. It was this improved communication that led to this important discovery.
DARPA press release Technical details
