Branch-cut Singularities in Thermodynamics of Fermi Liquid Systems

Abstract

The recently measured spin susceptibility of the two dimensional electron gas exhibits a strong dependence on temperature, which is incompatible with the standard Fermi liquid phenomenology. Here we show that the observed temperature behavior is inherent to ballistic two dimensional electrons. Besides the single-particle and collective excitations, the thermodynamics of Fermi liquid systems includes effects of the branch-cut singularities originating from the edges of the continuum of pairs of quasiparticles. As a result of the rescattering induced by interactions, the branch-cut singularities generate non-analyticities in the thermodynamic potential which reveal themselves in anomalous temperature dependences. Calculation of the spin susceptibility in such a situation requires a non-perturbative treatment of the interactions. As in high-energy physics, a mixture of the collective excitations and pairs of quasiparticles can be effectively described by a pole in the complex momentum plane. This analysis provides a natural explanation for the observed temperature dependence of the spin susceptibility, both in sign and magnitude.

8 pages, 3 figures

References in corpus (5)

• Spin-independent origin of the strongly enhanced effective mass in a dilute 2D electron system
• Thermodynamics of a Fermi liquid in a magnetic field
• Thermodynamics of a Fermi liquid beyond the low-energy limit
• Magnetization of a strongly interacting two-dimensional electron system in perpendicular magnetic fields
• Temperature dependent spin susceptibility in a two-dimensional metal

Cited by in corpus (15)

• Magnetic Ordering of Nuclear Spins in an Interacting 2D Electron Gas
• Nonanalytic paramagnetic response of itinerant fermions away and near a ferromagnetic quantum phase transition
• Non-analytic spin susceptibility of a nested Fermi liquid: the case of Fe-based pnictides
• Spin susceptibility of interacting two-dimensional electrons in the presence of spin-orbit coupling
• Nonanalytic Magnetic Response of Fermi- and non-Fermi Liquids
• Lorentz ratio of a compensated metal
• Ferromagnetic order of nuclear spins coupled to conduction electrons: a combined effect of the electron-electron and spin-orbit interactions
• Temperature dependence of spin susceptibility in two-dimensional Fermi liquid systems
• Cooper channel and the singularities in the thermodynamics of a Fermi liquid
• Probing spin susceptibility of a correlated two-dimensional electron system by transport and magnetization measurements
• Nonanalyticities in a Strongly Correlated Fermi Liquid: Corrections to Scaling at the Fermi-Liquid Fixed Point
• Momentum dependence of the spin susceptibility in two dimensions: nonanalytic corrections in the Cooper channel
• Specific heat of a one-dimensional interacting Fermi system: the role of anomalies
• Low energy excitations and singular contributions in the thermodynamics of clean Fermi liquids
• Landau Quasiparticles in Weak Power-Law Liquids