Stanford Advisors


All Publications


  • Publisher Correction: Carrier density and disorder tuned superconductor-metal transition in a two-dimensional electron system. Nature communications Chen, Z., Swartz, A. G., Yoon, H., Inoue, H., Merz, T. A., Lu, D., Xie, Y., Yuan, H., Hikita, Y., Raghu, S., Hwang, H. Y. 2018; 9 (1): 4570

    Abstract

    The original HTML version of this Article omitted to list Harold Y. Hwang as a corresponding author and incorrectly listed Adrian G. Swartz as a corresponding author. This has been corrected in the HTML version of the Article. The PDF version was correct from the time of publication.

    View details for PubMedID 30374115

  • Superconducting Tunneling Spectroscopy of Spin-Orbit Coupling and Orbital Depairing in Nb :SrTiO3 PHYSICAL REVIEW LETTERS Swartz, A. G., Cheung, A. C., Yoon, H., Chen, Z., Hikita, Y., Raghu, S., Hwang, H. Y. 2018; 121 (16): 167003

    Abstract

    We have examined the intrinsic spin-orbit coupling and orbital depairing in thin films of Nb-doped SrTiO_{3} by superconducting tunneling spectroscopy. The orbital depairing is geometrically suppressed in the two-dimensional limit, enabling a quantitative evaluation of the Fermi level spin-orbit scattering using Maki's theory. The response of the superconducting gap under in-plane magnetic fields demonstrates short spin-orbit scattering times τ_{so}≤1.1  ps. Analysis of the orbital depairing indicates that the heavy electron band contributes significantly to pairing. These results suggest that the intrinsic spin-orbit scattering time in SrTiO_{3} is comparable to those associated with Rashba effects in SrTiO_{3} interfacial conducting layers and can be considered significant in all forms of superconductivity in SrTiO_{3}.

    View details for PubMedID 30387624

  • Carrier density and disorder tuned superconductor-metal transition in a two-dimensional electron system. Nature communications Chen, Z., Swartz, A. G., Yoon, H., Inoue, H., Merz, T. A., Lu, D., Xie, Y., Yuan, H., Hikita, Y., Raghu, S., Hwang, H. Y. 2018; 9 (1): 4008

    Abstract

    Quantum ground states that arise at atomically controlled oxide interfaces provide an opportunity to address key questions in condensed matter physics, including the nature of two-dimensional metallic behaviour often observed adjacent to superconductivity. At the superconducting LaAlO3/SrTiO3 interface, a metallic ground state emerges upon the collapse of superconductivity with field-effect gating and is accompanied with a pseudogap. Here we utilize independent control of carrier density and disorder of the interfacial superconductor using dual electrostatic gates, which enables the comprehensive examination of the electronic phase diagram approaching zero temperature. We find that the pseudogap corresponds to precursor pairing, and the onset of long-range phase coherence forms a two-dimensional superconducting dome as a function of the dual-gate voltages. The gate-tuned superconductor-metal transitions are driven by macroscopic phase fluctuations of Josephson coupled superconducting puddles.

    View details for PubMedID 30275443