Marios H. Michael, Eugene Demler, Patrick A. Lee. "Parametrically amplified Josephson plasma waves in YBa
                    <sub>2</sub>
                    Cu
                    <sub>3</sub>
                    O
                    <sub>
                      6+
                      <i>x</i>
                    </sub>
                    : Evidence for local superconducting fluctuations up to the pseudogap temperature
                    <i>T</i>
                    <sup>∗</sup>." Proceedings of the National Academy of Sciences (2026). https://doi.org/10.1073/pnas.2606129123