LOCAL CONTROL METHOD FOR METAL-INSULATOR TRANSITION BY FINE PROBE AND METHOD FOR READING LOCAL PATTERN THEREOF

摘要

PROBLEM TO BE SOLVED: To facilitate the reading of local patterns by locally inducing Mott transition of an electronic system by STM probe scanning on the surface of a laminar material in a metal state and executing STM observation with an adequate bias voltage by utilizing the spectral difference between a metal region and an insulator region. SOLUTION: The laminar material TaS2 is put into the state in which the phase transition thereof is liable to occur at a temp. of about 190 K. The material is then subjected to STM probe scanning, by which the phase transition is irreversibly formed only in this part. The Mott transition of the electronic system is induced locally by the STM probe scanning on the surface of the laminar material in the metal state, by which the excitation spectra of the electrons are changed and a gap structure is formed at a Fermi level. The local Mott transition is induced by scanning the desired space region under suitable voltage and current conditions. STM observation is executed with the adequate bias voltage by utilizing the spectral difference between the metal region and the insulator region, by which the distinct reading of the written patterns is made possible.