Intertwining of multiphase charge density waves in In-intercalated TaSe2

Disorder caused by defects plays an important role on the emergence of exotic physical phenomena in quantum states of materials, including charge density waves (CDWs). Usually, the coexistence of multiphase CDWs aroused by defects is manifested in multiple domains resulting from phase separation. By using scanning tunneling microscopy, we reveal an intertwining of two CDW phases without explicit domain boundaries on a cleaved surface of layered intercalation compounds InxTaSe2 (x = 0.58), which undergoes commensurate CDW transitions twice by cooling. The two CDW phases, i.e., 2 x a root 3 and 2 x 2 phases at higher and lower temperature, respectively, have very similar atomic arrangements in the TaSe2 layers and thus are very sensitive to the random potentials induced by the intercalated In atoms. Moreover, the translational symmetry breaking of the 2 x root 3 phase results in the presence of another intertwined root 7 x root 7 phase. These findings provide insight into the microscopic effect of defects on multiphase CDWs and reveal a coexisting manner of CDW phases.