Gate‐controlled metal–insulator transition in the LaAlO3/SrTiO3 system with sub‐critical LaAlO3 thickness |
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| Authors: | Joon Sung Lee Sang Keun Seung Seung Ran Lee Jung‐Won Chang Hyunho Noh Lkhagvasuren Baasandorj Hyun Sup Shin Seung‐Bo Shim Jonghyun Song Jinhee Kim |
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| Affiliation: | 1. Korea Research Institute of Standards and Science, Daejeon 305‐600, Republic of Korea;2. Department of Physics, Chungnam National University, Daejeon 305‐764, Republic of Korea |
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| Abstract: | We studied the electrical conduction in the LaAlO3/SrTiO3 (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) |
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| Keywords: | LaAlO3 SrTiO3 oxides heterostructures metal− insulator transition |
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