Structural and electronic inhomogeneity of superconducting Nb-doped Bi2Se3
| Autor: | Yu-Te Hsu, Martin Bremholm, Laura Wollesen, Davide Curcio, Deepnarayan Biswas, Henriette E. Lund, Marco Bianchi, Steffen Wiedmann, Ann Julie Holt, Simone M. Kevy, Alfred J. H. Jones, Cephise Cacho, Kirstine J. Dalgaard, Philip Hofmann, Klara Volckaert, Pavel Dudin |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Superconductivity
Materials science Condensed matter physics Photoemission spectroscopy Angle-resolved photoemission spectroscopy 02 engineering and technology Electronic structure Crystal structure 021001 nanoscience & nanotechnology 01 natural sciences Coherence length Condensed Matter::Superconductivity 0103 physical sciences 010306 general physics 0210 nano-technology Critical field Surface states |
| Zdroj: | Physical Review B. 103 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.103.085107 |
| Popis: | The crystal structure, electronic structure, and transport properties of crystals with the nominal composition ${\mathrm{Nb}}_{0.25}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ are investigated. X-ray diffraction reveals that the as-grown crystals display phase segregation and contain major contributions of BiSe and the superconducting misfit layer compound ${(\mathrm{Bi}\mathrm{Se})}_{1.1}\mathrm{Nb}{\mathrm{Se}}_{2}$. The inhomogeneous character of the samples is also reflected in the electronic structure and transport properties of different single crystals. Angle-resolved photoemission spectroscopy (ARPES) reveals an electronic structure that resembles poor-quality ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ with an ill-defined topological surface state. High-quality topological surface states are instead observed when using a highly focused beam size, i.e., nanoARPES. While the superconducting transition temperature is found to vary between 2.5 and 3.5 K, the majority of the bulk single crystals does not exhibit a zero-resistance state suggesting filamentary superconductivity in the materials. Susceptibility measurements of the system together with the temperature dependence of the coherence length extracted from the upper critical field are consistent with conventional BCS superconductivity of a type II superconductor. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|