2004/01/21 by Ilya Vekhter, I. Vekhter, Andrey V. Chubukov +1 · 2 citations
Materials Science · Physics and Astronomy · #Antiferromagnetism #Condensed matter physics #Critical point (mathematics) #Fermi liquid theory #Fermion #Iron-based superconductors research #Omega #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum critical point #Quantum mechanics #Quantum phase transition #Quasiparticle #Rare-earth and actinide compounds #Scaling #Spin (aerodynamics) #Superconductivity #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.93.016405
published as Phys. Rev. Lett. v. 93, p. 016405 (2004) · 5p., 3figs
arxiv created 2004/01/21 · openalex publication_date 2004/07/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We consider a two-dimensional itinerant antiferromagnet near a quantum-critical point. We show that, contrary to conventional wisdom, fermionic excitations in the ordered state are not the usual Fermi-liquid quasiparticles. Instead, down to very low frequencies, the fermionic self-energy varies as \ensuremathω2/3. This non-Fermi-liquid behavior originates in the coupling of fermions to the longitudinal spin susceptibility \ensuremathχ_\ensuremath∥(q,\ensuremathΩ) in which the order-induced ``gap'' in the spectrum at q=0 dissolves into the Landau damping term at vFq>\ensuremathΩ. The transverse spin fluctuations obey the z=1 scaling characteristic of spin waves, but remain overdamped in a finite range near the critical point.