Searching for Neutrinoless Double-Beta Decay of ${}^{136}$Xe with PandaX-4T

We report the search for neutrinoless double-beta decay of ${}^{136}$Xe from the PandaX-4T experiment with a 3.7-tonne natural xenon target. The data reconstruction and the background modeling are optimized in the MeV energy region. A blind analysis is performed with data from the commissioning run and the first science run. No significant excess of signal over the background is observed. A lower limit on the half-life of ${}^{136}$Xe neutrinoless double-beta decay is established to be $2.1\times {10}^{24}$~yr at the 90% confidence level, with a ${}^{136}$Xe exposure of 44.6~kg$\cdot$year. Our result represents the most stringent constraint from a natural xenon detector to date.