Oral: Electrical transport study of strained α-Sn thin films

Tin (Sn) has recently gained considerable attention for its remarkable capacity to host both superconducting and topological phases. Within this context, the α-Sn phase is known for its ability to transition between various topological phases through the manipulation of factors such as strain, magnetic field, and film thickness. When subjected to in-plane compressive strain, α-Sn has been reported to show characteristics of a topological Dirac semimetal (TDS). In this work, we have successfully verified the growth of smooth and epitaxial α-Sn thin films employing buffer layers to modulate strain using molecular beam epitaxy. Our characterization efforts incorporate the detailed analysis of crystal structure and surface morphology. We employ systematic electrical transport studies on these strained α-Sn thin films. Notably, we delved into the evolution of topological phases within these thin films by examining the Shubnikov-de Haas oscillations with varying strain. Additionally, we observed the occurrence of negative magnetoresistance, which could be an indication of a chiral anomaly and the presence of the Weyl semimetal (WS) phase when an in-plane magnetic field was applied. The exploration of these TDS/WS phases for α-Sn not only provides an intriguing platform for unraveling novel physics but also holds promise for practical applications in the realms of spintronics and quantum technologies.