Discovery of higher charge superconductivity beyond charge-2e Cooper pairs

Despite of the various forms of superconductivity, conventional or unconventional, topologically trivial or nontrivial, the condensation of charge-2e Cooper pairs has remained the origin and character of all superconductivity, as described by the BCS theory. We report our experimental discoveries of the charge-4e and charge-6e superconductivity in ultrathin ring devices fabricated using the kagome superconductor CsV3Sb5. These new phase coherent states are discovered by the observation of the quantized magnetic flux in units of h/4e and h/6e in systematic magneto-transport measurements. Our observations provide direct experimental evidence for the existence of phase coherent paired quantum matter beyond the charge-2e superconductors, and provide ground work for exploring the physical properties of the charge-4e and charge-6e superconductivity as unprecedented phases of matter beyond the condensation of Cooper pairs described by the BCS theory.