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Abstracts
I1.3
Quantum criticality and novel phases in heavy fermion metals
Silke Paschen
Vienna University of Technology, Austria
Heavy fermion materials are prototype systems to study quantum criticality:
the application of non-thermal control parameters such as magnetic field or
pressure frequently induces a continuous phase transition at absolute zero in
temperature. Quantum fluctuations emerging from such a ”quantum critical
point” (QCP) lead to exotic behaviour that cannot be accounted for by Landau
Fermi liquid theory and is thus called non-Fermi liquid behaviour. Frequently,
new phases, including unconventional superconductivity, form in the vicinity
of a QCP. After an overview of the field I will present recent efforts to extend
the temperature scale of such studies to ultralow temperatures using cooling by
nuclear demagnetization.
O1.7
One-Dimensional Liquid
4
He and Hard-Core Systems: Dynamical
Properties beyond Luttinger-Liquid Theory
Bertaina Gianluca(1), Motta Mario(2), Rossi Maurizio(3,4,5), Vitali Ettore(2),
Galli Davide Emilio (1)
(1) Universit`a degli Studi di Milano, Dipartimento di Fisica, via Celoria 16,
I-20133 Milano, Italy
(2) The College of William and Mary, Department of Physics, Williamsburg,
Virginia 23187, USA
(3) Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
(4) International Center for Theoretical Physics (ICTP), Strada Costiera 11,
I-34154 Trieste, Italy
(5) Universit`a degli Studi di Padova, Dipartimento di Fisica e Astronomia,
via Marzolo 8, I-35131 Padova, Italy
Low-energy properties of one-dimensional liquid
4
He can be described by
Luttinger-liquid theory. By means of quantum Monte Carlo and analytic
continuation techniques, we compute the density structure factor also at higher
energies at zero temperature [1]. Such quantity reveals the evolution from a highly
compressible liquid to a quasisolid regime, manifesting a pseudo-particle-hole
continuum typical of fermionic systems. At high density, we observe a novel
behavior that can be interpreted with the hard-rods model, whose dynamics
we investigate. Our results are compatible with some predictions by nonlinear
Luttinger-liquid theory.
[1] G. Bertaina et al., Phys. Rev. Lett. 116, 135302 (2016)
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