Electric gating of the multichannel conduction in LaAlO_(3)/SrTiO_(3) superlattices  

作　　者：Shao-Jin Qi Xuan Sun Xi Yan Hui Zhang Hong-Rui Zhang Jin-E Zhang Hai-Lin Huang Fu-Rong Han Jing-Hua Song Bao-Gen Shen Yuan-Sha Chen 齐少锦;孙璇;严曦;张慧;张洪瑞;张金娥;黄海林;韩福荣;宋京华;沈保根;陈沅沙(Beijing National Laboratory for Condensed Matter Physics and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [2]School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Physics B》2021年第1期477-482,共6页中国物理B（英文版）

基　　金：Project supported by the National Basic Research Program of China(Grant Nos.2016YFA0300701,2017YFA0206300,2017YFA0303601,and2018YFA0305704);the National Natural Science Foundation of China(Grant Nos.11520101002,51590880,11674378,11934016,and 51972335);the Key Program of the Chinese Academy of Sciences。

摘　　要：The electric gating on the transport properties of two-dimensional electron gas(2DEG) at the interface of LaAlO_(3)/SrTiO_(3)(LAO/STO) heterostructure has attracted great research interest due to its potential application in fieldeffect devices. Most of previous works of gate effect were focused on the LAO/STO heterostructure containing only one conductive interface. Here, we systematically investigated the gate effect on high-quality LAO/STO superlattices(SLs)fabricated on the TiO_(2)-terminated(001) STO substrates. In addition to the good metallicity of all SLs, we found that there are two types of charge carriers, the majority carriers and the minority carriers, coexisting in the SLs. The sheet resistance of the SLs with a fixed thickness of the LAO layer increases monotonically as the thickness of the STO layer increases. This is derived from the dependence of the minority carrier density on the thickness of STO. Unlike the LAO/STO heterostructure in which minority and majority carriers are simultaneously modulated by the gate effect, the minority carriers in the SLs can be tuned more significantly by the electric gating while the density of majority carriers is almost invariable. Thus, we consider that the minority carriers may mainly exist in the first interface near the STO substrate that is more sensitive to the back-gate voltage, and the majority carriers exist in the post-deposited STO layers. The SL structure provides the space separation for the multichannel conduction in the 2 DEG, which opens an avenue for the design of field-effect devices based on LAO/STO heterostructure.

关 键 词：SUPERLATTICES gate effect minority carriers majority carriers 

分 类 号：TN03[电子电信—物理电子学] TB34[一般工业技术—材料科学与工程]