Berlin 2015 – wissenschaftliches Programm
TT 71.25: Poster
Mittwoch, 18. März 2015, 15:00–18:00, Poster B
Suppression of critical fluctuations of electronic Ising-nematicity by coupling to the crystal lattice — •Christopher Max1, Achim Rosch1, Indranil Paul2, and Markus Garst1 — 1Institute for theoretical Physics, Universitiy of Cologne, Zülpicher Str. 77, 50937 Cologne, Germany — 2Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot-Paris 7 & CNRS, UMR 7162, 75205 Paris, France
Nematic instabilities of the electronic Fermi surface are relevant for various strongly-correlated systems like the ruthenates or the Fe-based superconductors. At the same time, they serve as a theoretical paradigm for quantum phase transitions in metals whose properties at lowest temperature still remain unclear and are the topic of current research. In the present work, we point out that the Ising-nematic order parameter strongly hybridizes with the strain field of the crystal, and, as a consequence, the nematic transition is naturally accompanied with a tetragonal-orthorhombic distortion. Due to the long-range shear forces of the crystal, the quantum critical properties will be eventually governed by quantum critical elasticity . Upon approaching the quantum critical point, a crossover occurs from critical non-Fermi liquid behavior to conventional metallicity while the phonon sectors becomes soft resulting in an anomalous phonon specific heat Cph ∼ T2.5 at lowest temperature. We discuss the various crossovers for thermodynamics as well as for the electronic spectral function.
 M. Zacharias, I. Paul and M. Garst, arXiv:1411.6925