ON6.1 - Group of Theory of Topological Matter
Researchers in the Theory Group at MagTop, by using effective Hamiltonian, empirical tight binding, and ab initio methods, develop theories of topological matter aiming at inspiring materials development teams as well as help in the interpretation of experimental results. The Team members collaborate with many groups in Europe and Japan. Particularly interesting and challenging is collaboration with the VIGO Photonics in determining band structure of detector-relevant multilayer devices.
Researchers from the MBE Group at MagTop are focusing on developing MBE growth technologies for various types of epilayers and nanostructures with topological characteristics, composed of both II-VI (e.g. based on CdTe and HgTe), IV-VI semiconductors (such as. e.g. topological crystalline insulators based on SnTe and SnSe) and elemental α-Sn. Particular emphasis is placed on in situ and ex situ interfacing of topological materials with ferromagnetism and superconductivity, via doping and deposition of overlayers.
ON6.3 - Group of Characterization and Processing
The characterization and processing team’s research focuses on the generation and manipulation of spin current in the magnetic material and topological material bilayer thin films and nanostructures. We use nanolithography methods, such as electron beam lithography, to fabricate the samples. Subsequently, we study them using global spin-wave spectroscopy and local Brillouin light scattering microscopy techniques as a function of temperature, magnetic field, and current.
Group research focuses on topological effects in condensed matter systems, particularly in superconductors, semiconductors, and magnetic materials with application to quantum information. More specifically, effects of magnetic adatoms in topological superconductors, topological defects (dislocations and declinations), flat band formation in topological nodal-line semimetals, and the entanglement of solid state spins in semiconducting nanostructures are examples of current research.
Research focuses on topological effect in condensed matter systems: Majorana spintronics in systems that interface superconductivity and magnetism with topological matter, spontaneous time-reversal symmetry breaking in electron-hole bilayers, machine-learning assisted identification of topological phases, topological properties of open quantum systems, topological phases in SnTe materials, and correlated states and topological phases in flat-band systems such as twisted bilayer graphene.
The Weyl group is oriented towards experimental investigations of topological materials. The expertise of the team members ranges from single crystal growth techniques, to the unique material characterisation methods, but the main goal of the team is to study the unusual transport properties of topological systems. The flow of the electrical and thermal currents in the presence of a magnetic field results in a wealth of physical phenomena. The analysis of their mutual relations requires the highest proficiency, but allows one to draw detailed conclusions about a system under study.