2013 Fiscal Year Final Research Report
Spin physics and two dimensional superconductivity on semiconductor surfaces
| Project/Area Number |
23740233
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Condensed matter physics I
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| Research Institution | The University of Tokyo |
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Principal Investigator |
MASUTOMI Ryuichi 東京大学, 理学(系)研究科(研究院), 助教 (00397027)
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| Project Period (FY) |
2011 – 2012
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| Keywords | 表面・界面 |
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| Research Abstract |
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.
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