Spin physics and two dimensional superconductivity on semiconductor surfaces

半导体表面的自旋物理和二维超导

• 批准号: 23740233
• 负责人: MASUTOMI Ryuichi
• 金额: $ 2.91万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (B)
• 财政年份: 2011
• 资助国家: 日本
• 起止时间: 2011 至 2012
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-23740233/
• 关键词: 表面・界面; 半導体表面; 2次元電子系; 低次元超伝導; ２次元電子系; 低次元超伝導体

An adsorbate-induced two-dimensional electron system (2DES) and superconductivity in one-atomic-layer Pb films at cleaved surfaces of InSb and GaAs are investigated by a low-temperature scanning tunneling microscope and spectroscopy combined with transport measurements in magnetic fields up to 14 T. We observed not only a STM image of Fe atoms at an InSb surface but also the spatially-averaged density of states in an adsorbate-induced 2DES. Moreover, we measured the parallel magnetic field dependence of the superconducting transition temperature Tc for a monolayer Pb film. The reduction in Tc is only a few % in magnetic fields up to 14 T, which is one order of magnitude higher than that of the Pauli limit. The observed weak parallel magnetic field dependence of Tc is explained in terms of an inhomogeneous superconducting state (helical state) predicted for 2D metals with a large Rashba spin splitting.

通过低温扫描隧道显微镜和光谱学结合磁场中的输运测量，研究了吸附物诱导的二维电子系统 (2DES) 和 InSb 和 GaAs 解理表面单原子层 Pb 薄膜的超导性14 T。我们不仅观察了 InSb 表面 Fe 原子的 STM 图像，还观察了吸附物诱导的 2DES 中的空间平均态密度。此外，我们测量了单层 Pb 薄膜的超导转变温度 Tc 与平行磁场的关系。在高达 14 T 的磁场中，Tc 仅降低了百分之几，这比泡利极限高了一个数量级。观察到的 Tc 的弱平行磁场依赖性可以用预测具有大 Rashba 自旋分裂的二维金属的不均匀超导状态（螺旋状态）来解释。

项目成果

GaAs劈開表面上に形成した金属超薄膜の超伝導

GaAs 解理表面上形成的超薄金属薄膜的超导性

• 发表时间: 2012
• 作者: 関原貴之;枡富龍一;岡本徹
• 通讯作者: 岡本徹

In-plane magnetic field dependence of cyclotron relaxation time in a Si two-dimensional electron system

Si 二维电子系统中回旋加速器弛豫时间的面内磁场依赖性

• DOI: 10.1103/physrevb.86.045310
• 发表时间: 2012
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: T. Chiba;R. Masutomi;K. Sawano;Y. Shiraki;and T. Okamoto
• 通讯作者: and T. Okamoto

Cyclotron resonance in the two-dimensional metallic phase of Siquantum wells

Siquantum 井二维金属相中的回旋共振

• DOI: 10.1088/1742-6596/334/1/012057
• 发表时间: 2011
• 期刊: AIP Conference Proceedings
• 作者: R.Masutomi;K.Sasaki;I.Yasuda;A.Sekine;K.Sawano;Y.Shiraki;T.Okamoto
• 通讯作者: T.Okamoto

Temperature, electron density and in-plane magnetic field dependence of cyclotron relaxation time in the two-dimensional metallic phase

二维金属相回旋弛豫时间的温度、电子密度和面内磁场依赖性

• DOI: 10.1088/1742-6596/456/1/012027
• 发表时间: 2013
• 期刊: Journal of Physics: Conference Series
• 作者: R. Masutomi;T. Chiba;K. Sasaki;I. Yasuda;A. Sekine;K. Sawano;Y. Shiraki;T. Okamoto
• 通讯作者: T. Okamoto

Magnetic-field-independent superconductivity of ultrathin Pb films on cleaved GaAs surface

解理 GaAs 表面上超薄 Pb 薄膜的磁场无关超导性

• DOI: 10.1088/1742-6596/456/1/012034
• 发表时间: 2013
• 期刊: Journal of Physics: Conference Series
• 作者: T. Sekihara;R. Masutomi;and T. Okamoto
• 通讯作者: and T. Okamoto