Nonequilibrium dynamical mean field theory
Event details
| Date | 20.03.2026 |
| Hour | 15:15 › 16:15 |
| Speaker | Prof. Philipp Werner, University of Fribourg, Switzerland |
| Location | |
| Category | Conferences - Seminars |
| Event Language | English |
Abstract: Dynamical mean field theory, which maps a lattice system onto an effective impurity problem, is a versatile tool for the study of correlated electron systems. I will explain the extension of this formalism to nonequilibrium problems [1], and describe some impurity solvers, which have been used to solve the nonequilibrium DMFT equations. As a first application, I will show how AC electric field quenches can be used to control the electron-electron interaction in metals [2]. The second application is the demonstration of an η-pairing state with high effective temperature in photo-doped Mott insulators [3].
[1] Hideo Aoki, Naoto Tsuji, Martin Eckstein, Marcus Kollar, Takashi Oka, Philipp Werner, Nonequilibrium dynamical mean-field theory and its applications, Rev. Mod. Phys. 86, 779 (2014).
[2] Naoto Tsuji, Takashi Oka, Philipp Werner, Hideo Aoki, Dynamical band flipping in fermionic lattice systems: An ac-field-driven change of the interaction from repulsive to attractive, Phys. Rev. Lett. 106, 236401 (2011).
[3] Lei Geng, Aaram J. Kim, Philipp Werner, High-temperature η-pairing superconductivity in the photodoped Hubbard model, arXiv:2602.17238 (2026).
Bio:
Philipp Werner is a specialist on the dynamical mean field simulation of strongly correlated electron systems. His development of powerful numerical algorithms has enabled systematic investigations of important classes of correlated materials, such as unconventional superconductors, and has opened new lines of research. In particular, the development of non-equilibrium dynamical mean field theory over the past 10 years has resulted in a versatile theoretical framework for the study of ultrafast processes in solids. Philipp Werner studied physics at EPFL. His Master thesis advisor was Prof. Jürg Fröhlich from ETHZ. He did his PhD at ETHZ under the supervision of Prof. Matthias Troyer. After a postdoc at Columbia University with Prof. Andrew J. Millis, he returned to Switzerland in 2008 as Swiss National Science Foundation Professor at the Institute for Theoretical Physics at ETHZ. He then joined the University of Fribourg as Associate Professor in 2012 where he got promoted to full Professor in Fribourg in 2018.
[1] Hideo Aoki, Naoto Tsuji, Martin Eckstein, Marcus Kollar, Takashi Oka, Philipp Werner, Nonequilibrium dynamical mean-field theory and its applications, Rev. Mod. Phys. 86, 779 (2014).
[2] Naoto Tsuji, Takashi Oka, Philipp Werner, Hideo Aoki, Dynamical band flipping in fermionic lattice systems: An ac-field-driven change of the interaction from repulsive to attractive, Phys. Rev. Lett. 106, 236401 (2011).
[3] Lei Geng, Aaram J. Kim, Philipp Werner, High-temperature η-pairing superconductivity in the photodoped Hubbard model, arXiv:2602.17238 (2026).
Bio:
Philipp Werner is a specialist on the dynamical mean field simulation of strongly correlated electron systems. His development of powerful numerical algorithms has enabled systematic investigations of important classes of correlated materials, such as unconventional superconductors, and has opened new lines of research. In particular, the development of non-equilibrium dynamical mean field theory over the past 10 years has resulted in a versatile theoretical framework for the study of ultrafast processes in solids. Philipp Werner studied physics at EPFL. His Master thesis advisor was Prof. Jürg Fröhlich from ETHZ. He did his PhD at ETHZ under the supervision of Prof. Matthias Troyer. After a postdoc at Columbia University with Prof. Andrew J. Millis, he returned to Switzerland in 2008 as Swiss National Science Foundation Professor at the Institute for Theoretical Physics at ETHZ. He then joined the University of Fribourg as Associate Professor in 2012 where he got promoted to full Professor in Fribourg in 2018.
Practical information
- General public
- Free
Organizer
- Professor Gregor Jotzu
Contact
- Professor Gregor Jotzu