Observation of the Signatures of Glassy Vortex Dynamics in 2$H$-NbSe$_{2 }$

Using time resolved transport measurements, we observed clear evidence of glassy dynamics in the current driven vortex system in clean, weak pinning 2$H$-NbSe$_{2 }$single crystals prepared by field cooling through the superconducting transition. Simple aging was observed by means of scaling over the waiting times between two consecutive current pulses. A memory function was defined to describe how the previous pulse is ``memorized'' when the system is probed by a second pulse. The complex behavior of the driven vortex system in the glassy state is well characterized by a simple picture of the time evolution of the glassy states in configuration space. Preliminary results on direct imaging of the current driven vortices using Hall probe microscopy will be discussed.