Band structure, superconductivity, and polytypism in AuSn4

The orthorhombic compound AuSn4 is compositionally similar to the Dirac node arc semimetal PtSn4. AuSn4 is, contrary to PtSn4, superconducting with a critical temperature of Tc=2.35 K. Recent measurements present indications for quasi-two-dimensional superconducting behavior in AuSn4. Here we presen...

Descripción completa

Detalles Bibliográficos
Autores: Herrera Vasco, Edwin, Wu, Beilun, O'Leary, Evan, Ruiz, Alberto M., Águeda, Miguel, Talavera, Pablo García, Barrena Escolar, Víctor, Azpeitia, Jon, Munuera, Carmen, García-Hernández, Mar, Wang, Lin Lin, Kaminski, Adam, Canfield, Paul C., Baldoví, José J., Guillamón Gómez, Isabel, Suderow Rodríguez, Hermann Jesús
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/708304
Acceso en línea:http://hdl.handle.net/10486/708304
https://dx.doi.org/10.1103/PhysRevMaterials.7.024804
Access Level:acceso abierto
Palabra clave:Band Structure
Crystal Structure
Density Functional Theory
CS Theory
Critical Temperatures
Densities of State
Binary Alloys
Física
Descripción
Sumario:The orthorhombic compound AuSn4 is compositionally similar to the Dirac node arc semimetal PtSn4. AuSn4 is, contrary to PtSn4, superconducting with a critical temperature of Tc=2.35 K. Recent measurements present indications for quasi-two-dimensional superconducting behavior in AuSn4. Here we present measurements of the superconducting density of states and the band structure of AuSn4 through scanning tunneling microscopy and angular resolved photoemission spectroscopy (ARPES). The superconducting gap values in different portions of the Fermi surface are spread around Δ0=0.4 meV, which is close to but somewhat larger than Δ=1.76kBTc expected from BCS theory. We observe superconducting features in the tunneling conductance at the surface up to temperatures about 20% larger than bulk Tc. The band structure calculated with density functional theory follows well the results of ARPES. The crystal structure presents two possible stackings of Sn layers, giving two nearly degenerate polytypes. This makes AuSn4 a rather unique case with a three-dimensional electronic band structure but properties ressembling those of low-dimensional layered compounds

Similares en LA Referencia