  Understanding of the metal-insulator transition (MIT) in correlated
transition-metal oxides is a fascinating topic in condensed matter physics and
a precise control of such transitions plays a key role in developing novel
electronic devices. Here we report an effective tuning of the MIT in epitaxial
SrVO3 (SVO) films by expanding the out-of-plane lattice constant without
changing in-plane lattice parameters, through helium ion irradiation. Upon
increase of the ion fluence, we observe a MIT with a crossover from metallic to
insulating state in SVO films. A combination of transport and magnetoresistance
measurements in SVO at low temperatures reveals that the observed MIT is mainly
ascribed to electron-electron interactions rather than disorder-induced
localization. Moreover, these results are well supported by the combination of
density functional theory and dynamical mean field theory (DFT+DMFT)
calculations, further confirming the decrease of the bandwidth and the enhanced
electron-electron interactions resulting from the expansion of out-of-plane
lattice constant. These findings provide new insights into the understanding of
MIT in correlated oxides and perspectives for the design of unexpected
functional devices based on strongly correlated electrons.
