2003/08/04 by Hyun-Tak Kim, B. G. Chae, Byung Gyu Chae +8
Engineering · Materials Science · Physics and Astronomy · #Advanced Memory and Neural Computing #Gas Sensing Nanomaterials and Sensors #Transition Metal Oxide Nanomaterials #cond-mat.str-el
paper · pdf · doi:10.1088/1367-2630/6/1/052
published as New J. Phys. 6 (2004) 52 · 4 pages, 4 figures
arxiv created 2003/08/04 · openalex publication_date 2004/05/18 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
When holes of about 0.018% are induced into a conduction band (breakdown of critical on-site Coulomb energy), an abrupt first-order Mott metal–insulator transition (MIT) rather than a continuous Hubbard MIT near a critical on-site Coulomb energy U / U c =1, where U is on-site Coulomb energy between electrons, is observed on an inhomogeneous VO 2 film, a strongly correlated Mott insulator. As a result, discontinuous jumps of the density of states on the Fermi surface are observed and inhomogeneity inevitably occurs. The off-current and temperature dependences of the abrupt MIT in a two-terminal device and the gate effect in a three-terminal device are clear evidence that the abrupt Mott MIT was induced by the excitation of holes. Raman spectra measured by a micro-Raman system show an MIT without the structural phase transition. Moreover, the magnitude of the observed jumps Δ J observed at the abrupt MIT is an average over an inhomogeneous measurement region of the maximum true jump, Δ J true , deduced from the Brinkman–Rice picture. A brief discussion of whether VO 2 is a Mott insulator or a Peierls insulator is presented.