Scanning tunneling spectroscopy study of electric-pulse-induced electronic inhomogeneities in GaTa$_{4}$Se$_{8}$

We have recently discovered a bulk Electric Pulse Induced Insulator-Metal Transition and possible superconductivity in the cluster Mott Insulator GaTa$_{4}$Se$_{8 }$[1]. The transport measurements, conducted on single crystals, are consistent with a two-channel model, which suggests that the electric pulse generates electronic inhomogeneities in the bulk of the samples. Our Scanning Tunneling Microscopy/Spectroscopy experiments indeed confirmed that the observed drop in the electric resistance originates from an electronic phase separation with the coexistence of metallic- like and insulating like domains at the nanometer scale [1]. [1] Vaju \textit{et al.} Advanced Materials, \textbf{20} 2760 (2008), Microelectronics engineering \textit{in press}, (2008)