Unusual Dirac fermions on the surface of noncentrosymmetric $\alpha$ - BiPd superconductor

Abstract

Combining multiple emergent correlated properties such as superconductivity and magnetism within the topological matrix can have exceptional consequences in garnering new and exotic physics. Here, we study the topological surface states from a noncentrosymmetric $\alpha$-BiPd superconductor by employing angle-resolved photoemission spectroscopy (ARPES) and first principle calculations. We observe that the Dirac surface states of this system have several interesting and unusual properties, compared to other topological surface states. The surface state is strongly anisotropic and the in-plane Fermi velocity varies rigorously on rotating the crystal about the $y$-axis. Moreover, it acquires an unusual band gap as a function of $k_y$, possibly due to hybridization with bulk bands, detected upon varying the excitation energy. Coexistence of all the functional properties, in addition to the unusual surface state characteristics make this an interesting material.

submitted on 26th April, 2016; to appear in PRL

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Cited by in corpus (16)

• Spin-triplet pairing state evidenced by half-quantum flux in a noncentrosymmetric superconductor
• Observation of Dirac surface states in the hexagonal PtBi2, a possible origin of the linear magnetoresistance
• Fermi surface, possible unconventional fermions, and unusually robust resistive critical fields in the chiral-structured superconductor AuBe
• Quantum oscillations and a non-trivial Berry phase in the noncentrosymmetric superconductor BiPd
• Dirac State in a Centrosymmetric Superconductor alpha-PdBi2
• Anomalies in the core level spectroscopy of a noncentrosymmetric solid, BiPd
• Strong-Coupling Superconductivity with $T_c$ $\sim$ 10.8 K Induced by P Doping in the Topological Semimetal Mo${}_5$Si${}_3$
• Correct Brillouin zone and electronic structure of BiPd
• Exceptional Dirac states in a non-centrosymmetric superconductor, BiPd
• Low-Energy Surface States in the Normal State of $\alpha$-PdBi2 Superconductor
• Kinetic stabilization of 1D surface states near twin boundaries in noncentrosymmetric BiPd
• Fermi surface and band structure of BiPd from ARPES studies
• Atomic-scale tailoring of spin susceptibility via non-magnetic spin-orbit impurities
• Temperature dependence of the lower critical field of the noncentrosymmetric superconductor $\alpha$-BiPd
• Anomalous spectral evolution with bulk sensitivity in BiPd
• Ab initio study of orbital-selective superconductivity in $\gamma$-BiPd