Quantum advantage shown with shallow circuits, despite errors

Researchers have demonstrated that constant-depth quantum circuits, even with noise and limited to three-dimensional operations, can solve a specific computational problem with near-certainty. The work reveals that classical AC⁰ circuits of size smaller than a certain superpolynomial (in fact subexponential) value will fail to solve the same problem with near-certainty on a random instance, highlighting a performance gap. This constitutes "a proposal with built-in fault-tolerance to experimentally observe the strongest known complexity-theoretic separation between classical and quantum computation." The findings sidestep the need for fully fault-tolerant quantum computers, pursuing quantum advantage with significantly more modest resources. Researchers detailed this performance gap in a recent paper published in Nature Communications, demonstrating a…