Nonvolatile Control of Metal–Insulator Transition in VO<sub>2</sub> by Ferroelectric Gating
Yoon Jung Lee, Kootak Hong, Kyeongho Na, Jiwoong Yang, Tae Hyung Lee, Byung‐Soo Kim, Chung Wung Bark, Jae Young Kim, Sung Hyuk Park, Sanghan Lee, Ho Won Jang
Abstract
Abstract Controlling phase transitions in correlated materials yields emergent functional properties, providing new aspects to future electronics and a fundamental understanding of condensed matter systems. With vanadium dioxide (VO 2 ), a representative correlated material, an approach to control a metal–insulator transition (MIT) behavior is developed by employing a heteroepitaxial structure with a ferroelectric BiFeO 3 (BFO) layer to modulate the interaction of correlated electrons. Owing to the defect‐alleviated interfaces, the enhanced coupling between the correlated electrons and ferroelectric polarization is successfully demonstrated by showing a nonvolatile control of MIT of VO 2 at room temperature. The ferroelectrically‐tunable MIT can be realized through the Mott transistor (VO 2 /BFO/SrRuO 3 ) with a remanent polarization of 80 µC cm −2 , leading to a nonvolatile MIT behavior through the reversible electrical conductance with a large on/off ratio (≈10 2 ), long retention time (≈10 4 s), and high endurance (≈10 3 cycles). Furthermore, the structural phase transition of VO 2 is corroborated by ferroelectric polarization through in situ Raman mapping analysis. This study provides novel design principles for heteroepitaxial correlated materials and innovative insight to modulate multifunctional properties.