Electric‐Field‐Assisted Nanostructuring of a Mott Insulator

Abstract

Abstract Here, the first experimental evidence for a strong electromechanical coupling in the Mott insulator GaTa 4 Se 8 that allows highly reproducible nanoscaled writing by means of scanning tunneling microscopy (STM) is reported. The local electric field across the STM junction is observed to have a threshold value above which the clean (100) surface of GaTa 4 Se 8 becomes mechanically instable: at voltage biases >1.1 V, the surface suddenly inflates and comes in contact with the STM tip, resulting in nanometer‐sized craters. The formed pattern can be indestructibly “read” by STM at a lower voltage bias, thus allowing 5 Tdots inch −2 dense writing/reading at room temperature. The discovery of the electromechanical coupling in GaTa 4 Se 8 might give new clues in the understanding of the electric pulse induced resistive switching recently observed in this stoichiometric Mott insulator.