Research dr Wiedmann
Fundamental research on quantum materials in combination with the development of instrumentation that we also make available for external users.
The core of the group's research program is based on studying the electronic, structural and thermodynamic properties of emergent materials including topological semi-metals, correlated electron systems and novel semiconductors from bulk materials to thin films. Characterizing and tuning the properties of novel states of matter is essential for their fundamental understanding and a crucial step towards the design and manufacturing of novel functional devices.
Research highlights
- Nodal-line semimetals: Fermi surface and magnetic breakdown in ZrSiS, Unconventional mass enhancement in ZrSiS,Quasi-particle tunneling in HfSiS
- Topological matter:Quantum oscillations in SnTe, Surface quantum Hall effect in strained HgTe, Negative longitudinal magneto-resistance in topological insulator Bi2Se3
- Thermal expansion and magnetostriction (under uniaxial strain):Magnetic crystal CdCr2O4, lead halide perovskites
- (novel) semiconductors (2D): graphene superlattices, the origin of linear magneto-resistance, chirality of graphene
TOPCORE Consortium grant - Driving quantum phase transitions in topological correlated matter
This proposal sets out to discover new physical phenomena and functionalities derived from the confluence of many-body interactions and topological protection in condensed matter systems. The consortium, consisting of experts in cutting-edge materials science, experimentation and state-of-the-art theory, aims at merging these hitherto distinct fields in order to unveil the profound influence of electron correlations on the fundamental properties of topological matter and vice versa. Our strategy is to explore new emergent phenomena made accessible by carefully selected material platforms and a unique combination of tunable environments - such as extreme magnetic fields, pressure, doping or strain – in order to advance our understanding of interacting topological systems and in particular, the prospects for new physics and functionality in the vicinity of topological quantum phase transitions.
Topology in condensed matter
- topological semi-metals: Dirac and Weyl semi-metals
- nodal-line semi-metals
- correlated topological matter
- topological insulators: edge and surface transport, Quantum Hall effect, Shubnikov-de Haas effect, magnetoresistance
- topological crystalline and Kondo insulators (PbTe based compounds, SmB6)
- charge transport in thin films of emergent materials (preparation + ionic liquid gating in collaboration with the group of Prof. Ye at Groningen University)
Correlated electron systems
- high-Tc superconductors
- emergent phases in correlated systems
- rare‐earth tri-telluride quantum materials
- phase transitions in condensed matter
(low-dimensional and novel) semiconductors
- Emergent materials for photovoltaics: lead halide perovskites and double perovskites
- Integer and fractional quantum Hall effect in conventional and novel material systems
- (Unconventional) magneto-resistance in 3D bulk semiconductors
- Non-linear magneto-transport phenomena
- Thermoelectric properties
- 1D and 0D transport – confinement and size effects
- Transport properties and phenomena in graphene, graphite and transition metal dichalcogenides
- Artificial honeycomb lattices: silicene, germanene, stanene