Fermi surface, possible unconventional fermions, and unusually robust resistive critical fields in the chiral-structured superconductor AuBe
- Louisiana State Univ., Baton Rouge, LA (United States)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States). National High Magnetic Field Lab. (MagLab)
- Louisiana State Univ., Baton Rouge, LA (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
- Univ. of Texas at Dallas, Richardson, TX (United States)
The noncentrosymmetric superconductor (NCS) AuBe is investigated using a variety of thermodynamic and resistive probes in magnetic fields of up to 65 T and temperatures down to 0.3 K. Despite the polycrystalline nature of the samples, the observation of a complex series of de Haas–van Alphen (dHvA) oscillations has allowed the calculated band structure for AuBe to be validated. This permits a variety of BCS parameters describing the superconductivity to be estimated, despite the complexity of the measured Fermi surface. In addition, AuBe displays a nonstandard field dependence of the phase of dHvA oscillations associated with a band thought to host unconventional fermions in this chiral lattice. Overall, this result demonstrates the power of the dHvA effect to establish the properties of a single band despite the presence of other electronic bands with a larger density of states, even in polycrystalline samples. In common with several other NCSs, we find that the resistive upper critical field exceeds that measured by heat capacity and magnetization by a considerable factor. We suggest that our data exclude mechanisms for such an effect associated with disorder, implying that topologically protected superconducting surface states may be involved.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Louisiana State Univ., Baton Rouge, LA (United States)
- Sponsoring Organization:
- USDOE; National Science Foundation (NSF)
- Grant/Contract Number:
- 89233218CNA000001; DMR1206763; FG02-07ER46420; DMR1306392; DMR1700030; DMR-1157490
- OSTI ID:
- 1772412
- Alternate ID(s):
- OSTI ID: 1546192; OSTI ID: 2283901
- Report Number(s):
- LA-UR-18-31277; TRN: US2206962
- Journal Information:
- Physical Review. B, Vol. 99, Issue 9; ISSN 2469-9950
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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Anisotropic upper critical field of pristine and proton-irradiated single crystals of the magnetically ordered superconductor
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