Some new concepts for me but interesting and a good step forward.
A team of researchers working on DARPA’s Optimization with Noisy Intermediate-Scale Quantum devices (ONISQ) program has created the first-ever quantum circuit with logical quantum bits (qubits), a key discovery that could accelerate fault-tolerant quantum computing and revolutionize concepts for designing quantum computer processors.
The ONISQ program began in 2020 seeking to demonstrate a quantitative advantage of quantum information processing by leapfrogging the performance of classical-only supercomputers to solve a particularly challenging class of problem known as combinatorial optimization. The program pursued a hybrid concept to combine intermediate-sized “noisy”— or error-prone — quantum processors with classical systems focused specifically on solving optimization problems of interest to defense and commercial industry. Teams were selected to explore various types of physical, non-logical qubits including superconducting qubits, ion qubits, and Rydberg atomic qubits.
The Harvard research team, supported by MIT, QuEra Computing, Caltech, and Princeton, focused on exploring the potential of Rydberg qubits, and in the course of their research made a major breakthrough: The team developed techniques to create error-correcting logical qubits using arrays of “noisy” physical Rydberg qubits. Logical qubits are a critical missing piece in the puzzle to realize fault-tolerant quantum computing. In contrast to error-prone physical qubits, logical qubits are error-corrected to maintain their quantum state, making them useful for solving a diverse set of complex problems.
