Laura Classen
Heidelberg University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Laura Classen.
Physical Review Letters | 2017
Laura Classen; Rui Qi Xing; Maxim Khodas; Andrey V. Chubukov
We report the results of the parquet renormalization group (RG) analysis of the phase diagram of the most general 5-pocket model for Fe-based superconductors. We use as an input the orbital structure of excitations near the five pockets made out of d_{xz}, d_{yz}, and d_{xy} orbitals and argue that there are 40 different interactions between low-energy fermions in the orbital basis. All interactions flow under the RG, as one progressively integrates out fermions with higher energies. We find that the low-energy behavior is amazingly simple, despite the large number of interactions. Namely, at low energies the full 5-pocket model effectively reduces either to a 3-pocket model made of one d_{xy} hole pocket and two electron pockets or a 4-pocket model made of two d_{xz}/d_{yz} hole pockets and two electron pockets. The leading instability in the effective 4-pocket model is a spontaneous orbital (nematic) order, followed by s^{+-} superconductivity. In the effective 3-pocket model, orbital fluctuations are weaker, and the system develops either s^{+-} superconductivity or a stripe spin-density wave. In the latter case, nematicity is induced by composite spin fluctuations.
Physical Review B | 2017
Rui Qi Xing; Laura Classen; Maxim Khodas; Andrey V. Chubukov
We report the results of a parquet renormalization group (RG) study of competing instabilities in the full 2D four pocket, three orbital low-energy model for iron-based superconductors. We derive and analyze the RG flow of the couplings, which describe all symmetry-allowed interactions between low-energy fermions. Despite that the number of the couplings is large, we argue that there are only two stable fixed trajectories of the RG flow and one weakly unstable fixed trajectory with a single unstable direction. Each fixed trajectory has a finite basin of attraction in the space of initial system parameters. On the stable trajectories, either interactions involving only
Physical Review B | 2016
Laura Classen; Igor F. Herbut; Lukas Janssen; Michael M. Scherer
d_{xz}
Physical Review B | 2012
Hernan L. Calvo; Laura Classen; Janine Splettstoesser; M. R. Wegewijs
and
Physical Review Letters | 2018
Laura Classen; Igor Zaliznyak; A. M. Tsvelik
d_{yz}
Physical Review B | 2014
Michael Golor; Timo Reckling; Laura Classen; Michael M. Scherer; Stefan Wessel
or only
Physical Review B | 2017
Laura Classen; Igor F. Herbut; Michael M. Scherer
d_{xy}
Physical Review B | 2015
Laura Classen; Igor F. Herbut; Lukas Janssen; Michael M. Scherer
orbital components on the electron pockets dominate, while on the weakly unstable trajectory interactions involving
Physical Review B | 2014
Laura Classen; Michael M. Scherer; Carsten Honerkamp
d_{xz}
arXiv: Strongly Correlated Electrons | 2018
Laura Classen; Igor Zaliznyak; A. M. Tsvelik
(