Department of Applied Physics Research Seminar: Dr. Timo Hyart
Dr. Timo Hyart is a team leader at the International Centre for Interfacing Magnetism and Superconductivity with Topological Matter in Warsaw, and currently a visiting researcher in the Correlated Quantum Materials group at Aalto University. Hyart’s research focuses on the theory of exciton condensates, superconductors, magnetism, topological materials, and topological quantum computation.
The quenched kinetic energy in the flat-band systems increases the importance of interactions and leads to superconductivity and other correlated states. I will discuss examples of symmetry-broken states in flat-band systems starting from the best understood quantum Hall ferromagnets and exciton condensates  and continuing with more complicated quantum Hall systems  and moiré superlattices  which are characterized by competition between different order parameters [3, 4]. I will emphasize that in contrast to the systems where the Fermi energy is the largest energy scale, the properties of the flat-band systems are determined by the whole band, including effects originating from the quantum metric of the Bloch wavefunctions [3,5,6]. Finally, I will discuss our proposal to design a three-dimensional flat band .
References  T. Hyart, B. Rosenow, Phys. Rev. B 83, 155315 (2011); D. I. Pikulin, P. G. Silvestrov, T. Hyart, Nature Communications 7, 10462 (2016).  Y. Li et al., Phys. Rev. B 101, 241405 (2020).  T. T. Heikkilä, T. Hyart, Europhys. News 50, 24 (2019).  R. Ojajärvi et al., Phys. Rev. B 98, 054515 (2018).  X. Hu, T. Hyart, D. I. Pikulin, E. Rossi, Phys. Rev. Lett. 123, 237002 (2019).  X. Hu, T. Hyart, D. I. Pikulin, E. Rossi, arXiv:2008.03241  A. Lau, T. Hyart et al., arXiv:2008.09122
Host: Prof. Jose Lado
Zoom link available on request to [email protected].