A quantum state with less magic can sometimes reach its goal faster than one that is already halfway there.
In quantum computing, magic or nonstabilizerness is a resource needed to perform calculations that classical computers cannot handle. This study found a quantum version of the Mpemba effect where starting further from a magical state actually accelerates the process of getting there. It seems counterintuitive that having more of a resource at the start would make you slower to generate it. This effect happens because the path to higher magic is non-linear and depends on the initial complexity of the state. Understanding this can help us prep quantum computers for big tasks much more efficiently. It proves that the rules of quantum efficiency are often backwards compared to our daily experience.
Nonstabilizerness Mpemba Effects
arXiv · 2605.04155
Quantum state preparation can be strikingly counterintuitive: the fastest route to a target state need not start from the apparently closest initial condition. We uncover such a quantum Mpemba effect in the dynamical generation of quantum magic (nonstabilizerness), quantified by the stabilizer Rényi entropy, in $\mathrm{U(1)}$-symmetric random circuits initialized from tilted product states. States with lower initial magic can generate magic faster than states with higher initial magic. The acce