TY - JOUR

T1 - Electronic self-energy and triplet pairing fluctuations in the vicinity of a ferromagnetic instability in two-dimensional systems

T2 - Quasistatic approach

AU - Katanin, A. A.

PY - 2005/7/15

Y1 - 2005/7/15

N2 - The self-energy, spectral functions, and susceptibilities of two-dimensional systems with strong ferromagnetic fluctuations are considered within the quasistatic approach. The self-energy at low temperatures T has a non-Fermi-liquid form in the energy window ω Δ0 near the Fermi level, where Δ0 is the ground-state spin splitting for magnetically ordered ground state, and Δ T1 2ln1 2(vF T) in the quantum critical regime (vF is the Fermi velocity). Spectral functions have a two-peak structure at finite T above the magnetically ordered ground state, which implies quasisplitting of the Fermi surface in the paramagnetic phase in the presence of strong ferromagnetic fluctuations. The triplet pairing amplitude in the quasistatic approximation increases with increasing correlation length; at low temperatures T Δ0 the vertex corrections become important and the Eliashberg approach is not justified. The results for the spectral properties and susceptibilities in the quantum critical regime near charge (spin) instabilities with large enough correlation length ξ (T vF)-1 3 are obtained.

AB - The self-energy, spectral functions, and susceptibilities of two-dimensional systems with strong ferromagnetic fluctuations are considered within the quasistatic approach. The self-energy at low temperatures T has a non-Fermi-liquid form in the energy window ω Δ0 near the Fermi level, where Δ0 is the ground-state spin splitting for magnetically ordered ground state, and Δ T1 2ln1 2(vF T) in the quantum critical regime (vF is the Fermi velocity). Spectral functions have a two-peak structure at finite T above the magnetically ordered ground state, which implies quasisplitting of the Fermi surface in the paramagnetic phase in the presence of strong ferromagnetic fluctuations. The triplet pairing amplitude in the quasistatic approximation increases with increasing correlation length; at low temperatures T Δ0 the vertex corrections become important and the Eliashberg approach is not justified. The results for the spectral properties and susceptibilities in the quantum critical regime near charge (spin) instabilities with large enough correlation length ξ (T vF)-1 3 are obtained.

UR - http://www.scopus.com/inward/record.url?scp=33749158633&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.72.035111

DO - 10.1103/PhysRevB.72.035111

M3 - Article

AN - SCOPUS:33749158633

VL - 72

JO - Physical Review B - Condensed Matter and Materials Physics

JF - Physical Review B - Condensed Matter and Materials Physics

SN - 1098-0121

IS - 3

M1 - 035111

ER -