66 citations · 500 across the 14 of their papers we have counts for
10 papers · 1 filter
Thermodynamic signatures of a fractionalized Fermi liquid
Andreas Hackl, Ronny Thomale
Several heavy-fermion metals display a quantum phase transition from an antiferromagnetic metal to a heavy Fermi liquid. In some materials, however, recent experiments seem to find…
Zeeman-driven Lifshitz transition: A scenario for the Fermi-surface reconstruction in YbRh2Si2
Andreas Hackl, Matthias Vojta
The heavy-fermion metal YbRh2Si2 displays a field-driven quantum phase transition where signatures of a Fermi-surface reconstruction have been identified, often interpreted as brea…
New theoretical approaches for correlated systems in nonequilibrium
M. Eckstein, A. Hackl, S. Kehrein +4
We review recent developments in the theory of interacting quantum many-particle systems that are not in equilibrium. We focus mainly on the nonequilibrium generalizations of the f…
Non-equilibrium magnetization dynamics of ferromagnetically coupled Kondo spins
Andreas Hackl, Stefan Kehrein, Matthias Vojta
An analytical description of non-equilibrium phenomena in interacting quantum systems is rarely possible. Here we present one example where such a description can be achieved, name…
Quasiparticle Nernst effect in stripe-ordered cuprates
Andreas Hackl, Matthias Vojta, Subir Sachdev
Experiments on underdoped cuprate superconductors suggest an intricate relation between the normal-state Nernst effect and stripe order: The Nernst signal appears enhanced near 1/8…
Nonequilibrium Spin Dynamics in the Ferromagnetic Kondo Model
Andreas Hackl, David Roosen, Stefan Kehrein +1
Motivated by recent experiments on molecular quantum dots we investigate the relaxation of pure spin states when coupled to metallic leads. Under suitable conditions these systems…
Nernst effect in the electron-doped cuprates
Andreas Hackl, Subir Sachdev
We calculate the normal state Nernst signal in the cuprates resulting from a reconstruction of the Fermi surface due to spin density wave order. An order parameter consistent with…
Unitary perturbation theory approach to real-time evolution problems
A. Hackl, S. Kehrein
We discuss a new analytical approach to real-time evolution in quantum many-body systems. Our approach extends the framework of continuous unitary transformations such that it amou…
Kondo volume collapse, Kondo breakdown, and Fermi surface transitions in heavy-fermion metals
Andreas Hackl, Matthias Vojta
The unconventional critical behavior near magnetic quantum phase transitions in various heavy-fermion metals, apparently inconsistent with the standard spin-density-wave scenario,…
Real Time Evolution in Quantum Many-Body Systems With Unitary Perturbation Theory
A. Hackl, S. Kehrein
We develop a new analytical method for solving real time evolution problems of quantum many-body systems. Our approach is a direct generalization of the well-known canonical pertur…