Width-induced metal–insulator transition in SrVO₃ lateral nanowires spontaneously formed on the ultrathin film

We investigated lateral nanowires at the topmost layer of SrVO₃ (001) ultrathin films using in situ low-temperature scanning tunneling microscopy and spectroscopy. The nanowires were spontaneously formed in the topmost layer of SrVO₃ with a (√2 × √2)-R45° reconstruction on the terrace of a (√5 × √5)-R26.6° reconstruction. The electronic states of nanowires were significantly influenced by the nanowire width. With reducing the nanowire width from 5.5 nm to 1.7 nm, the zero-bias conductance of nanowires steeply decreased toward zero, exhibiting a metal–insulator transition possibly driven by dimensional crossover, previously observed in thickness-reduced SrVO₃ ultrathin films.