Theoretical physics of condensed matter is one of the most progressive parts of modern physics. The wealth of systems studied by condensed matter physics provides opportunities for fascinating physical phenomena and open new ways for technological innovations.

Physics goes quantum

The basic physics of many phenomena studied by condensed matter physics happens on the atomic scale, where quantum properities of atoms and charge carriers become important. Thus condensed matter can serve as a real playground for quantum-mechanical effects. With advent of new materials and technologies the quatum-relativistic physics in condesed matter have become more important. An important manifestation of relativistic behaviour in condensed matter is coupling of spins and orbital momenta, called spin-orbit interaction. This interactions appears to be important ingredient for novel materials with possible application in spintronics.

  • Frietsch B., Donges A., Carley R., Teichmann M., Bowlan J., Döbrich K., Carva K., Legut D., Oppeneer P.M., Nowak U., Weinelt M.,
    The role of ultrafast magnon generation in the magnetization dynamics of rare-earth metals.
    Science advances, 6(39) (2020)

Studying new materials

In our group we focus on various aspects of quantum physics in the solid state of matter. In close collaboration with experiment we study basic physical properties of novel functional materials for spintronics featuring magnetic moments and/or spin-orbital interaction. Apart from standard three-dimensional bulk materials with disorder (like diluted magnetic semiconductors) we study also effects on interfaces, two-dimensional materials (like graphene), one-dimensional structures (like quantum wires), and zero-dimensional systems (like quantum dots). Especially, we focus on quantum transport in these structures, which is of great importance for engineering of novel technical applications.

  • A. Kadlecová, M. Žonda, V. Pokorný and T. Novotný,
    Practical guide to quantum phase transitions in quantum-dot-based tunable Josephson junctions,
    Physical Review Applied 11, 044094 (2019)

Proposing new devices

For novel technological applications, more complex structures need to be proposed and studied. On one hand side we study magnetotransport through multilayer structures consisted of magnetic layers separated by nonmagnets. These structures are well know for a possibility of manipulating with their magnetizations by means of spin transfer torque. The effect of spin transfer torque has a potential for magnetic random access memories. Spin transfer torque acts on magnetic domain wall in single magnetic layers when electric current flows in the layer's plane. This effect gives rise to an alternative geometry of magnetic memory known as magnetic racetrack memory.

An important class systems with quantum-based functionality are molecular junctions.

  • F. Evers, R. Korytár, S. Tewari, J. M. van Ruitenbeek,
    Advances and challenges in single-molecule electron transport,
    Reviews of Modern Physics 92, 035001 (2020)

Developing new methods

To study the problems of condensed matter physics, we use both paper-and-pencil theory as well as numerical calculations. For studying the basic physical features of materials with atomistic input we use ab initio and multiscale approaches. In our group not only we use accesible numerical software but also develope our own numerical codes.

We apply machine learning methods for the investigation of complex condensed matter systems.

  • J. Arnold, F. Schäfer, M. Žonda and A. U. J. Lode,
    Interpretable and unsupervised phase classification,
    Phys. Rev. Research 3, 033052, (2021)