Colloids are promising model systems to investigate the phase behavior of matter at length scales and time scales accessible to optical microscopy. We utilize disordered quasi two-dimensional soft colloidal systems in the jammed state to study the properties of glasses. It was recently found that so-called �soft spots�, in which the energy of low frequency eigenmodes is quasi-localized, are the locations in glasses where rearrangements are most likely to happen. We utilize short laser pulses to perturb colloidal glasses locally. By varying the pulse intensity of the laser, the size of the perturbation is tunable which allows us to induce elastic or plastic deformations in the glasses. Thus we investigate the correlation between locally induced rearrangements in the colloidal glass and the location of soft spots determined from analysis of the system's vibrational eigenmodes. The dependence of the mechanical response of a glass on the local environment is discussed.

Local perturbation of quasi-2D soft colloidal glasses

244th National Meeting (2012)

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