Projects

National

ROTOLES – Optimalizovaný rast a transportné a optické vlastnosti tenkých vrstiev vybraných topologických polokovov
Optimised growth and the transport and optical properties of thin layers of selected topological semimetals
Program: SRDA
Project leader: Dr. rer. nat. Hulman Martin
Annotation: One of the fundamental results of quantum mechanics in the 1920s was the derivation of relativistic equations formassive fermions (Dirac), massless fermions (Weyl) and fermions that are themselves antiparticles (Majorana).Since those times, particle physics has been searching for particles representing Weyl and Majorana\’s fermions.However, their search has not yet been successful.In the last twenty years, it has been shown that the band structure of some materials has such uniquecharacteristics that the charge carriers in them can behave according to the dynamics satisfying the Dirac or Weylrelativistic equations. Such materials include compounds from the group of transition metals dichalcogenides,which we will focus on in our project.We will work with very thin layers of selected materials from this group, such as PtSe2, MoTe2 and WTe2. The firststep in the implementation of the project will be the preparation of such layers by chalcogenisation of thin films oftransition metals. Their transport and optical properties will then be thoroughly investigated. Temperaturedependent transport measurements can show us transitions between different structures of the same material. We expect that a metal-insulator transition can be observed when the thickness of such thin films is varied. Some ofthese materials can go into a superconducting state at very low temperatures. We will also try to induce this state inclose proximity, i.e. when the thin layer is in contact with another superconductor.Optical measurements will be correlated with transport measurements. We derive essential frequency-dependentcharacteristics, such as optical conductivity, from the latter. We will look for characteristics theoretically predictedfor Dirac and Weyl fermions in the optical conductivity.
Duration: 1.7.2024 – 30.6.2027