Quantifying the Weak Antilocalization Effect in GeSn Alloys

ORAL

Abstract

Germanium tin alloys are of interest for expanding the range of Group IV electronic properties including bandgap engineering, transport properties, and quantum transport effects such as spin-orbit coupling. However, little is known regarding the extent to which Sn incorporation in Ge alters its electronic structure. Here we show that p-GeSn thin films exhibit strong spin-orbit interactions in the form of the Weak Antilocalization (WAL) effect. In this study, the temperature-dependent WAL effect is investigated in a series of GeSn thin films with varied carrier densities. Phase coherence and spin-orbit length-scales are extracted from the magnetoconductivity of these films using the 2D Hikami-Larkin-Nagaoka model. Phase coherence lengths are on the order of 250 nm at the lowest temperatures, decreasing with a power law temperature dependence, while the spin-orbit lengths of approximately 25 nm are comparatively independent of carrier density and temperature. These results show that GeSn is an excellent candidate for applications in which long phase coherence lengths and strong spin-orbit coupling interactions are desirable.

* This work was supported as part of μ-ATOMS, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under award DE-SC0023412. This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. DOE's National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in the article do not necessarily represent the views of the U.S. DOE or the United States Government.

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Presenters

  • Adelaide Bradicich

    Sandia National Labs

Authors

  • Adelaide Bradicich

    Sandia National Labs

  • Priyanka Petluru

    Sandia National Labs

  • Haochen Chao

    University of Delaware

  • Yuping Zeng

    University of Delaware

  • Tzu-Ming Lu

    Sandia National Laboratories

  • Michael P Lilly

    Sandia National Laboratories

  • Chia-You Liu

    Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan

  • Jiun-Yun Li

    National Taiwan University (NTU), National Taiwan University, National Taiwan University, Taiwan Semiconductor Research Institute