Superconductivity and Shubnikov - de Haas effect in polycrystalline Cd3As2 thin films

Leonid N. Oveshnikov,Alexey V. Suslov,Alexey I. Ril’,Sergey F. Marenkin,Alexander B. Davydov,Boris A. Aronzon,Alexander L. Vasiliev

doi:10.1038/s41598-020-61376-6

Abstract

In this study we observed the reproducible superconducting state in Cd3As2 thin films without any external stimuli. Comparison with our previous results reveals similar qualitative behavior for films synthesized by different methods, while the difference in the values of the critical parameters clearly shows the possibility to control this state. The X-ray diffraction measurements demonstrate the presence of the tetragonal Cd3As2 crystal phase in studied films. Measurements of high-field magnetoresistance reveal pronounced Shubnikov - de Haas oscillations. The analysis of these oscillations suggests that, due to high carrier concentration in studied Cd3As2 films, the initial Dirac semimetal phase may be partially suppressed, which, however, does not contradict with possible topological nature of the observed superconductivity.

Highlights

Dirac materials became one of the most intensively studied areas of condensed matter physics
It is worth mentioning, that the majority of these studies were limited to small magnetic fields, where the SC state was observed, while they lacked data on the conservation of various features typical for native DSM phase, questioning the actual reasons for the topological SC (TSC) to occur
We report the realization of reproducible superconductivity in Cd3As2 thin films without application of any external factors

Summary

Introduction

Dirac materials became one of the most intensively studied areas of condensed matter physics. For interpretation of such data one needs to take into account various effects related to the symmetry lowering due to crystal deformation or to the details of heterogeneous systems It is worth mentioning, that the majority of these studies were limited to small magnetic fields, where the SC state was observed, while they lacked data on the conservation of various features typical for native DSM phase, questioning the actual reasons for the TSC to occur. We argue that SC is the universal feature of polycrystalline Cd3As2 films Both (i) presence of Cd3As2 tetragonal crystalline phase and (ii) Shubnikov - de Haas oscillations observed in high magnetic fields suggest preservation of the DSM phase in studied films. We propose such polycrystalline thin films as a promising playground to study superconducting DSM systems

Methods

Results

Conclusion