Research

At the core of IMPRS-CPQM is the research that we carry out, to which our PhD students make a major contribution. Thanks to the scale of our facilities we cover a broad range of topics in modern physics and chemistry research into quantum materials. As it befits an interdisciplinary IMPRS like ours, we do not only cross boundaries between physics and chemistry in a large number of research topics, but rather choose a dedicated collaborative approach between research groups from different disciplines. Research fields covered by IMPRS-CPQM include, but not are not restricted to: 

Chemistry and physics of actinide compounds
Thanks to a long-term investment in the appropriate facilities, MPI-CPfS has the rare capability of working safely with uranium and thorium. We will both invent and refine uranium and thorium compounds that hold the key to understanding some of the outstanding problems in the field of strong correlations.

Research groups: Grin, Hassinger, Doert

Intermetallic superconductors and novel thermoelectrics
Skills in the chemistry departments of MPI-CPfS and TU Dresden enable the synthesis of new compounds of scientific and technical interest from across the huge field of intermetallic compounds. These are refined and studied in collaboration with physics partners across the three participating institutions.

Research groups: Grin, Felser, Ruck, Schwarz, Chadov, Kreiner

Topological insulators and superconductors
A major theme of the Inorganic Chemistry department at MPI-CPfS, the Chemistry and Physics Departments at TU Dresden, and the condensed matter physics department at St Andrews is the search for new forms of topological matter. Specialities include Heusler compounds and layered bismuth-based compounds.

Research groups: Felser, Grigera, King, Wahl, Ruck, Davis, Vojta, Timm, Isaeva, Yan, Chadov

Strain and pressure tuning of quantum materials
Uniaxial strain and hydrostatic pressure are ideal probes for work at the physics/chemistry interface because they can mimic and inspire similar changes made by altering the chemical composition of materials. We have substantial expertise in both.

Research groups: Hicks, Mackenzie, Nicklas

Neutron diffraction and small-angle scattering
We will explore the phase diagrams of two classes of novel materials exhibiting nontrivial magnetically ordered phases. The first host spin spirals or skyrmion lattices, over a broad range of external parameters, including high magnetic fields and pressures. The materials of interest will include, among others, magnetoelectric multiferroics and noncentrosymmetric helimagnets. The second are lanthanide and actinide-based heavy-fermion compounds located near a magnetic instability, and iron-based high temperature superconductors.

Research groups: Inosov, Stockert

Nuclear magnetic resonance (NMR) and electron spin resonance spectroscopies
Here, the research focus is on unconventional multi-band superconductivity with complex order parameters and coupling mechanisms and on systems with strong spin orbit coupling (SOC), such as Kitaev honeycomb lattices and non-centrosymmetric helimagnets hosting a new form of magnetically ordered state, the Skyrmion lattice. Spin excitations in ferromagnetic critical 3d-electron systems as well as linear d-bands in Dirac- and Weyl-fermion systems are other important topics in solid state NMR.

Research groups: Baenitz, Sichelschmidt, Klauss

Quantum criticality
Thanks to unique capabilities for ultra-low temperature thermodynamic and transport measurements, NMR and muon spin relaxation spectroscopy across a large range of magnetic fields, we are ideally placed to study the properties of low temperature quantum critical points. These will be supported by study of relevant quantum critical field theories. Typical systems include intermetallic compounds as well as low-dimensional quantum magnets based on transition metal oxides and supramolecular organic heterostructures.

Research groups: Brando, Geibel, Grigera, Mackenzie, Klauss, Hassinger, Davis, Vojta

Photoemission and soft x-ray spectroscopy of correlated and topological matter
The complementarity between the high-resolution, low energy angle resolved photoemission group at St Andrews and the high-energy spectroscopic probes available at MPI- CPfS ensures broad coverage of the major time-averaged photon-based spectroscopies suitable to the physics/chemistry interfaces explored in this IMPRS.

Research groups: King, Laubschat, Tjeng

Muon spin relaxation spectroscopy
The competition and interplay of different electronic ground states, their respective order parameters and spin dynamics are studied via the local probes muon spin relaxation, NMR and Mössbauer spectroscopy in a wide range of temperature, pressure and external magnetic fields.

Research groups: Lee, Klauss

Micro- and mesoscale studies of quantum materials
A major new thrust at MPI-CPfS will be the design and construction of facilities enabling the study of micro-sized samples from across the range of correlated and topological matter. One of the benefits of these new capabilities will be the ability to work with individual crystallites of samples prepared using the techniques of solid-state chemistry, considerably expanding the chemistry-physics collaborative interface.

Research groups: Hicks, Mackenzie, Moll

Cryogenic scanning tunneling microscopy and spectroscopy
State-of-the-art facilities exist for sub-1K STM spectroscopy in St Andrews and at MPI-CPfS, providing both new spectroscopic information and a useful complement to the other bulk and surface spectroscopies at our disposal.

Research groups: Wahl, Davis, Wirth

Quantum chemistry and condensed matter theory
Our team will include expertise in all aspects of modern correlated electron, electronic structure and spectroscopic theory, which will both feed into the projects described above and involve further development of relevant theoretical models and tools.

Research groups: Braunecker, Hooley, Lovett, Rosner, Baranov, Vojta, Oka, Keeling, Wagner

Engineering the band-structure in 2-dimensional quantum conductors
Many novel 2D materials are synthesized such as all the transition metal dichalcogenides, silcene, borophene, and others more. Of interest is their chemical and physical tunablity to quantum-engineer band-gaps and other properties such as the existence of Dirac cones at will, to produce materials that are specially tailored to particular needs.

Research groups: Eng, King

Excitonic correlations in organic materials
The optical response of organic semiconductors is characterized by strong electron hole correlations leading to strong exciton binding. Our goal is the understanding of exciton electronic properties, such as binding energy, spin state (singlet or triplet), lifetime, diffusion lengths and transport. These are of fundamental interest and also key to the basic functioning of organic devices, in particular organic solar cells.

Research groups: Leo, Vandewal

Quantum many-body theory of superconductivity and magnetism
The main focus of the research is on ordered states such as unconventional superconductivity and complex, sometimes topologically non-trivial, magnetic phases. Models are carefully chosen in order to complement the experimental work represented in the IMPRS, and to yield physical insight into iron pnictides, cuprates, topological insulators and superconductors, magnetism in doped semiconductors and magnetic critical phenomena.

Research groups: Timm, Vojta

Low-temperature methods for the synthesis of inorganic bulk and nano-structured materials
We develop innovative methods for the synthesis and modification of complex inorganic materials from bulk samples down to the scale of few nanometres. These include, for example, reactions in ionic liquids, microwave-assisted polyol process, heterogeneous topochemical reactions, gas phase deposition and spark plasma sintering, and other forms of specific nanostructuring.

Research groups: Grin, Ruck, Kaskel, Schmidt, Gather, Samuel, Höfling

Chemical analysis and structure determination
Full chemical and structural characterisation of all kinds of synthesised materials can be performed by a wide range of techniques including, for example, inductively coupled plasma-atomic emission spectroscopy, X-ray diffraction, (high resolution) electron microscopy, and various spectroscopic methods.

Research groups: Grin, Ruck, Doert