Role of joule heating in electrically-driven metal insulator transition in vanadium oxide nanowires

Metal to insulator transition (MIT) in vanadium oxide system can be triggered by several external stimuli such as temperature, electric field, strain and light. Electrically driven MIT in single nanowire devices of crystalline vanadium oxide (W- doped VO$_{2}$, Ag-doped V$_{2}$O$_{5}$) is the topic of current study. Recent works on realizing switching devices using these materials have discussed the importance of Joule heating near the transition as supposed to a purely electric field induced effect. We propose a novel method for identifying the individual roles of Joule heating and/or electric field by analyzing the frequency response of the AC electric signal near the MIT in these devices. The method may also be used in other strongly correlated electron system to delineate the roles of individual microscopic conduction mechanisms near MIT.