Sunday 09 March 2025
The topological nodal-line semimetal Sn0.15NbSe1.75 has been a subject of intense study in recent years due to its unique properties, which could potentially lead to the creation of new quantum states of matter. Researchers have now used soft-point-contact spectroscopy to probe the material’s electronic structure and uncover some fascinating findings.
One of the key features of Sn0.15NbSe1.75 is its flat energy bands, which are thought to be responsible for its unusual superconducting properties. The researchers used a technique called point-contact Andreev reflection (PCAR) to study the material’s electronic structure. PCAR involves creating a small gap in the surface of the material and then measuring the current flowing through it.
The results showed that the material exhibits prominent asymmetric double peaks in its differential conductance, which is a characteristic signature of Fano resonance. This phenomenon occurs when two distinct tunneling paths interact with each other, causing the energy levels to shift and split. The researchers were able to model this behavior using a phenomenological double Fano resonance (DFR) model.
The DFR model revealed that the flat energy bands in Sn0.15NbSe1.75 are hybridized below a temperature of around 23 Kelvin, which is known as the hybridization temperature. This hybridization drives an opening of a pseudogap below a characteristic temperature of around 6.8 Kelvin.
In addition to these findings, the researchers also observed unusual upper critical fields in the material’s superconducting state. These fields increase linearly with decreasing temperatures from 0.4 times the critical temperature down to 0.01 times the critical temperature. This behavior is thought to be related to the exotic superconducting properties of the material.
The study of Sn0.15NbSe1.75 using PCAR has provided a new perspective on this fascinating material, and its unique electronic structure is likely to continue to be an important area of research in the coming years. The discovery of new quantum states of matter is often driven by the study of unusual materials like this one, and it’s possible that Sn0.15NbSe1.75 could play a key role in advancing our understanding of superconductivity.
The researchers’ use of PCAR to study the material’s electronic structure has provided a detailed picture of its behavior at the atomic level.
Cite this article: “Unveiling the Electronic Structure of Topological Nodal-Line Semimetal Sn0.15NbSe1.75”, The Science Archive, 2025.
Sn0.15Nbse1.75, Soft-Point-Contact Spectroscopy, Point-Contact Andreev Reflection, Fano Resonance, Double Fano Resonance, Hybridization Temperature, Pseudogap, Superconductivity, Upper Critical Fields, Quantum
