EXO-200 and nEXO

nEXO is a proposed next generation neutrinoless double beta decay experiment with a design sensitivity for the half-life of $^{136}$Xe neutrinoless double beta decay of $\sim10^{28}$~yr. The single-phase isotopically enriched liquid xenon time projection chamber design is based on the success of the EXO-200 experiment, which completed its physics run in 2018 with a total exposure of $234.1$~kg~yr. EXO-200 demonstrated ultra-low background construction techniques, good energy resolution, and excellent background discrimination based on multi-parameter measurements of events, enhanced through machine learning techniques. EXO-200 achieved a sensitivity of $5.0\times10^{25}$~yr and a limit on the half-life of $^{136}$Xe neutrinoless double beta decay of $3.5\times10^{25}$~yr at 90\% confidence level. Scaling up from the 200~kg EXO-200 to the 5~tonne nEXO detector will significantly increase the source mass as well as improve background discrimination through the monolithic detector design.