Spectral function of a localized fermion coupled to the Wilson-Fisher conformal field theory

Abstract

We describe the dynamics of a single fermion in a dispersionless band coupled to the 2+1 dimensional conformal field theory (CFT) describing the quantum phase transition of a bosonic order parameter with N components. The fermionic spectral functions are expected to apply to the vicinity of quantum critical points in two-dimensional metals over an intermediate temperature regime where the Landau damping of the order parameter can be neglected. Some of our results are obtained by a mapping to an auxiliary problem of a CFT containing a defect line with an external field which locally breaks the global O(N) symmetry.

26 pages, 4 figures; (v2) corrected typos

References in corpus (8)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• Quantum phase transitions of metals in two spatial dimensions: II. Spin density wave order
• Mott insulators in strong electric fields
• Theory of quantum impurities in spin liquids
• Valence bond solid order near impurities in two-dimensional quantum antiferromagnets
• Quantum criticality of reconstructing Fermi surfaces in antiferromagnetic metals
• Spin dynamics across the superfluid-insulator transition of spinful bosons
• Excited state spectra at the superfluid-insulator transition out of paired condensates

Cited by in corpus (19)

• Localized magnetic field in the $O(N)$ model
• The critical O(N) CFT: Methods and conformal data
• DC resistivity at the onset of spin density wave order in two-dimensional metals
• Spin Impurities, Wilson Lines and Semiclassics
• Quantum critical metals in $4-\epsilon$ dimensions
• Broken global symmetries and defect conformal manifolds
• A Scaling Limit for Line and Surface Defects
• Conductivity of weakly disordered strange metals: from conformal to hyperscaling-violating regimes
• Analytic bootstrap for the localized magnetic field
• The $g$-function and Defect Changing Operators from Wavefunction Overlap on a Fuzzy Sphere
• Line Defect RG Flows in the $\epsilon$ Expansion
• The epsilon expansion of the O$(N)$ model with line defect from conformal field theory
• Solving Conformal Defects in 3D Conformal Field Theory using Fuzzy Sphere Regularization
• Defects in scalar field theories, RG flows and Dimensional Disentangling
• Comments on epsilon expansion of the O$(N)$ model with boundary
• Fixed point annihilation for a spin in a fluctuating field
• RG Flows and Stability in Defect Field Theories
• Conformal line defects at finite temperature
• Fine Spectrum from Crude Analytic Bootstrap