Type-I superconductivity in noncentrosymmetric NbGe${}_2$

Abstract

Single crystals of NbGe${}_2$ which crystallize in a noncentrosymmetric hexagonal structure with chirality are synthesized and their superconductivity is investigated. Type-I superconductivity is confirmed by dc magnetization, field-induced second-to first-order phase transition in specific heat, and a small Ginzburg-Landau parameter ${\kappa }_{GL}=0.12$. The isothermal magnetization measurements show that there is a crossover from type-I to type-II/1 superconductivity with decreasing temperature and an unusually enhanced surface superconducting critical field ($H_{c3}$) is discovered. The band structure calculations indicate the presence of Kramer-Weyl nodes near the Fermi level. These observations demonstrate that NbGe${}_2$ is an interesting and rare example involving the possible interplay of type-I superconductivity, noncentrosymmetric structure and topological properties.

arXiv comment7 pages,6 figures

References in corpus (14)

• Superconductivity and spin-orbit coupling in non-centrosymmetric materials: a review
• Topological quantum properties of chiral crystals
• Superconductivity with topological surface state in SrxBi2Se3
• Beyond Triplet: Unconventional Superconductivity in a Spin-3/2 Topological Semimetal
• Dirac Surface States and Nature of Superconductivity in Noncentrosymmetric BiPd
• Type I superconductivity in the Dirac semimetal PdTe2
• Superconductivity in Rh${}_2$Ga${}_9$ and Ir${}_2$Ga${}_9$ without Inversion Symmetry
• Specific heat and magnetization of a ZrB12 single crystal: characterization of a type II/1 superconductor
• Type-I superconductivity in ScGa3 and LuGa3 single crystals
• Multi-gap superconductivity and Shubnikov-de Haas oscillations in single crystals of the layered boride OsB_2
• Fractional flux quanta at intrinsic metallic interfaces of noncentrosymmetric superconductors
• Type-I superconductivity in noncentrosymmetric superconductor AuBe
• Type-I superconductivity in Al${}_6$Re
• Signatures of the Helical Phase in the Critical Fields at Twin Boundaries of Non-Centrosymmetric Superconductors

Cited by in corpus (5)

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• An investigation of type-I superconductivity in single crystal of Pb2Pd
• Full superconducting gap and type-I to type-II superconductivity transition in single crystalline NbGe2
• Influence of pressure on properties of multi-gap type-I superconductor BeAu
• Absence of diode effect in chiral type-I superconductor NbGe2