Search for Majorana Neutrinos with Neutrinoless Double Beta Decay$\backslash $fs20

h $-abstract-$\backslash $pardNeutrinoless double beta decay provides a special window into some of the most fundamental properties of neutrinos, that are still unknown: (1) whether or not neutrinos are their own antiparticles (Majorana neutrinos), (2) what are the masses of the three types of neutrinos, and (3) whether or not there is charge-parity (CP) symmetry breaking in neutrinos. The current status of neutrinoless double beta decay in adressing these questions will be reviewed. The author is involved in the EXO-200 and nEXO double beta decay experiments using liquid $^{\mathrm{136}}$Xe. Some new results from EXO-200 and plans for nEXO, a ton-scale experiment, will be presented. For the second phase of nEXO, a technique is being developed to ``tag'' single $^{\mathrm{136}}$Ba atoms that result from $^{\mathrm{136}}$Xe double beta decay. Progress on barium tagging will also be discussed.$\backslash $fs20 $\backslash $pard-/abstract-$\backslash $\tex