Algorithms Require at Least N Rounds to Colour Cycles with Quantum Computers

A new lower bound demonstrates that any distributed quantum algorithm solving a 3-coloring problem on a cycle of computers with probability 1 requires Ω(n) communication rounds. Xavier Coiteux-Roy of the University of Waterloo and colleagues have shown that quantum computers offer no speed advantage when solving the 3-coloring of a cycle, a network where computers are connected in a closed loop. The team's findings isolate quantum computational power, as they do not rely on previous assumptions about the fundamental limits of information transfer. Xavier Coiteux-Roy and colleagues developed a new method to differentiate between…