Prof. RNDr. Václav Janiš, DrSc.

Office: C440b, UTIA-Building



Phone: +420 26605 2153


Email: janis@fzu.cz

Vita

Research

Publications (PDF)

Research interests:

Theory of strongly correlated electrons
Model description of electron correlations, Hubbard and Anderson impurity models, collective and cooperative phenomena, transition from weak to strong coupling regimes, breakdown of Fermi-liquid phase, (dynamical) mean-field theory for intermediate and strong coupling, Kondo and insulating regimes; implementation of electron correlations in realistic calculational schemes

Quantum coherence and quantum phase transitions in itinerant systems
Quantitative description of quantum criticality, interaction-driven quantum phase transitions in metals, effects of noncommutativity of relevant operators on critical behavior, formation of bound and resonant pair states, structure of order parameters of quantum phases, transverse magnetic order, superconductivity

Transport properties of disordered electron systems
Vertex corrections in the electrical conductivity in impure metals, quantum diffusion and coherence, diagrammatic theory of weak and strong electron localization, metal-insulator transition

Theory of spin glasses and other random systems
Mean-field theory based on real replicas in the thermodynamic approach of Thouless, Anderson and Palmer for Ising and Heisenberg spin glasses and related models

Field-theoretic and diagrammatic methods for quantum two-particle functions
Feynman diagrams and many-body Green functions for nonrelativistic quantum interacting systems, advanced approximations for two-particle Green functions, vertex corrections, parquet approach to two-particle vertex functions

Nonequilibrium phenomena
Quantum nonequilibrium systems, nonequilibrium Green functions and transport equations, x-ray edge problem and orthogonality catastrophe, two-level systems in a phonon bath

University courses:

Thermodynamics and Statistical Physics II

Path integral and classical trajectories (seminar)

Statistical physics of quantum many-particle systems I

Statistical physics of quantum many-particle systems II

Renormalization theory of phase transitions

Study opportunities

Diploma theses

• Magnetic properties of strongly correlated electron systems
• Development and Applications of Modern Electronic Structure Theory Methods

PhD theses

Research opportunities

Postdoc positions

Selected recent publications

V. Janiš and M. Ringel, Magnetic properties of metallic impurities with strongly correlated electrons, Acta Phys. Polon. A115 (2009) 30-36.

V. Janiš, A. Klíč and M. Ringel, Replica-symmetry breaking: discrete and continuous schemes in the Sherrington-Kirkpatrick model, J. Phys. A: Math. Theor. 41 324004 (2008) 1 - 14.

V. Janiš, Free-energy functional for the Sherrington-Kirkpatrick model: The Parisi formula completed, Phys. Rev. B77,104417 (2008) 1 - 5.

V. Janiš and P. Augustinský, Kondo behavior in the asymmetric Anderson model: Analytic approach, Phys. Rev. B77, 085106 (2008) 1-11.

V. Janiš and P. Augustinský, Analytic impurity solver with Kondo strong-coupling asymptotics, Phys. Rev. B75, 165108 (2007).

V. Janiš and A. Klíč, Hierarchical solutions of the Sherrington-Kirkpatrick model: Exact asymptotic behavior near the critical temperature, Phys. Rev. B74, 054410 (2006).

V. Janiš, Incompleteness of the Thouless, Anderson, and Palmer mean-field description of the spin-glass phase, Phys. Rev. B74, 054207 (2006).

V. Janiš and L. Zdeborová, Thermodynamic origin of order parameters in mean-field models of spin glasses, Phys. stat. sol. (b) 243, 716 (2006).