Magnetic Field Studies Near Superconducting Transition in MBE Grown Monolayer NbSe2 on Bilayer Graphene

ORAL

Abstract

Following the work by Frindt [1] on the superconductivity of NbSe2 at reduced thicknesses, recent breakthroughs have enabled the study of bilayers and monolayers. Staley et. al. [2], Tsen et. al. [3], Cao et. al. [4] and Xi et. al. [5] have studied superconductivity in bilayers and monolayers of NbSe2 after mechanical exfoliation and encapsulation with another layered material to protect from air. In this work, we have investigated the superconductivity in monolayer NbSe2 prepared by molecular beam epitaxy growth (MBE) on bilayer graphene (BLG) [6]. The superconducting transition has an onset temperature of 1.9K, midpoint temperature of 0.65K and reaches zero resistance at 0.46K. The upper critical field perpendicular to the NbSe2 monolayer is 0.5T at 100mK. We will show the effect of magnetic fields near the superconducting transition and compare with existing theories. [1] R. Frindt, Phys. Rev. Lett. 28, 299 (1972). [2] N. E. Staley, et. al., Phys. Rev. B 80, 184505 (2009). [3] A. W. Tsen, et. al., arXiv:1507.08639 [cond-Mat.supr-Con] 1 (2015). [4] Y. Cao, et. al., Nano Lett. 15, 4914 (2015). [5] X. Xi, et. al., arXiv:1507.08731 [cond-Mat.supr-Con] 1 (2015). [6] M. M. Ugeda, et al., Nat. Phys. 10.1038/nphys3527 (2015).

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Authors

  • Seita Onishi

    UC Berkeley/Lawrence Berkeley National Lab. (LBNL)

  • Miguel M. Ugeda

    UC Berkeley/CIC nanoGUNE

  • Yi Zhang

    LBNL/SLAC National Accelrator Lab.

  • Yi Chen

    UC Berkeley

  • Claudia Ojeda-Aristizabal

    Dept. of Physics and Astronomy California State University, UC Berkeley

  • Hyejin Ryu

    Lawrence Berkeley National Lab., Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA

  • Sung-Kwan Mo

    Lawrence Berkeley National Lab.

  • Zahid Hussain

    Lawrence Berkeley National Lab., Lawrence Berkeley National Laboratory

  • Zhi-Xun Shen

    SLAC National Accelrator Lab./Stanford University, Stanford Univ, Stanford University

  • Michael F. Crommie

    Univ of California - Berkeley, UC Berkeley/Kavli ENSI/LBNL, University of California, Berkeley, UCB Physics, LBNL MSD, and Kavli ENSI

  • Alex Zettl

    Dept. of Physics Univ. of California Berkeley, Lawrence Berkeley National Laboratory, Univ of California - Berkeley;Materials Sciences Division, LBNL;Kavli Energy NanoSciences Institute at the Univ of California, Berkeley and LBNL, UC Berkeley/Kavli ENSI/LBNL, University of California at Berkeley, Lawrence Berkeley National Laboratory; Univ of California, Berkeley, UCB Physics, LBNL MSD, and Kavli ENSI