Two-Dimensional Mott Insulators in SrVO3 Ultrathin Films
Two-Dimensional Mott Insulators in SrVO3 Ultrathin Films
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DOI：
10.1002/admi.201300126
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发表时间：
2014-10-01
影响因子：
5.4
通讯作者：
Lu, Jiwei
中科院分区：
文献类型：
--
作者：
Gu, Man;Wolf, Stuart A.;Lu, Jiwei
Strongly correlated oxides that undergo a metal-insulator transition (MIT) are a subject of great current interest for their potential application to future electronics as switches and sensors. Recent advances in thin film technology have opened up new avenues to tailor MIT for novel devices beyond conventional CMOS scaling. Here, dimensional-crossover-driven MITs are demonstrated in high-quality epitaxial SrVO3 (SVO) thin films grown by a pulsed electron-beam deposition technique. Thick SVO films (similar to 25 nm) exhibit metallic behavior with the electrical resistivity following the T-2 law corresponding to a Fermi liquid system. A temperature driven MIT is induced in SVO ultrathin films with thicknesses below 6.5 nm. The transition temperature T-MIT is at 50 K for the 6.5 nm film, 120 K for the 5.7 nm film and 205 K for the 3 nm film. The emergence of the observed MIT can be attributed to the dimensional crossover from a three-dimensional metal to a two-dimensional Mott insulator, as the resulting reduction in the effective bandwidth W opens a band gap at the Fermi level. The magneto-transport study of the SVO ultrathin films also confirm the observed MIT is due to the electron-electron interactions other than disorder-induced localization.
