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Gate‐controlled metal–insulator transition in the LaAlO 3 /SrTiO 3 system with sub‐critical LaAlO 3 thickness
Author(s) -
Lee Joon Sung,
Seung Sang Keun,
Lee Seung Ran,
Chang JungWon,
Noh Hyunho,
Baasandorj Lkhagvasuren,
Shin Hyun Sup,
Shim SeungBo,
Song Jonghyun,
Kim Jinhee
Publication year - 2012
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201206428
Subject(s) - materials science , controllability , condensed matter physics , metal–insulator transition , insulator (electricity) , metal , optoelectronics , physics , metallurgy , mathematics
We studied the electrical conduction in the LaAlO 3 /SrTiO 3 (LAO/STO) interface electron system with a sub‐critical LAO layer thickness of ∼3.5 unit cells (uc). It was found that the true dividing point between metallic and insulating behaviour without gating lies near the LAO thickness of 3.5 uc. Our marginally metallic 3.5 uc sample showed a sharp transition to insulating state at temperatures which strongly depended on the applied negative back‐gate voltage. The superior gate‐controllability of the sample was attributed to its sheet carrier density which was an order of magnitude lower than those of conducting LAO/STO samples with 4 uc or more of LAO layers. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)