The Anthony J Leggett Institute for Condensed Matter Special Theory Seminar, Andreas Gleis (Rutgers), "Quantum criticality and strange metallicity in heavy fermions and cuprates: insights from cluster dynamical mean-field theory"

Abstract: I present cluster Dynamical Mean-Field Theory (cDMFT) plus Numerical Renormalization Group (NRG) studies of the periodic Anderson model (PAM) and the Hubbard model, paradigmatic models for describing heavy fermions and cuprates, respectively.

In the PAM, our method captures a Kondo breakdown quantum critical point (QCP) marking a continuous transition between two Fermi liquids with different Fermi surface volumes. I will compare the single-particle properties of these phases and discuss aspects of the Luttinger sum rule. I will then turn to the quantum critical region governed by this QCP, where we find clear signatures of strange-metal physics. I will examine the properties of this regime, contrast them with those of a marginal Fermi liquid, and compare our results with experimental data.

In the second part of the talk, I will present recent results for the Hubbard model, where our method captures a doping-driven QCP separating a pseudogap phase from a normal Fermi liquid. Here, too, we find signatures of strange-metal physics in the quantum critical region. I will compare these results with those for the PAM, highlighting similarities and differences. Drawing on our findings for both models, I will argue that strange-metal optics arises from collective, short-range correlated current fluctuations, rather than from a linear-in-T electronic decay rate.

Zoom Link: https://illinois.zoom.us/my/icmt.seminar?pwd=ZU1KbnBLeXZLUmJKc0oyU205cDNDdz09

Meeting ID: 791 382 8328

Password: 106237