“…In the regime of mixed states, complex and anomalous dynamic phenomena have been observed 29,30 , under conditions which are particularly relevant for realistic systems such as cellular 31 or ionic liquids 32 , among others. Due to technical difficulties related with the limited optical resolution of confocal microscopy, or a) Electronic mail: mlaurati@fisica.ugto.mx the complexity of introducing selectivity in scattering techniques, experimental characterization of the structure and dynamics of concentrated binary colloidal mixtures has mainly focused on the study of the large component 23,[25][26][27][28] , with a few exceptions in which, however, only the dynamics of the small particles for specific size ratios or a limited number of compositions were investigated 11,24,29,30 . Here we report a systematic experimental investigation of the microscopic structural organization and the single-particle dynamics of the small component in glassy binary colloidal mixtures with moderate to large size ratios and different compositions.…”