2011/11/28 by Stefan Kirchner, Kevin Ingersent, Qimiao Si
Chemistry · Mathematics · Physics and Astronomy · #Advanced NMR Techniques and Applications #Boson #Critical point (mathematics) #Criticality #Mathematics #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum and electron transport phenomena #Quantum critical point #Quantum mechanics #Quantum phase transition #Renormalization group #Spin (aerodynamics) #cond-mat.stat-mech #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.85.075113
published as Phys. Rev. B 85, 075113 (2012) · 9 pages, 10 figures
arxiv created 2011/11/28 · openalex publication_date 2012/02/10 · arxiv updated 2012/02/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We revisit the critical behavior of the sub-Ohmic spin-boson model. Analysis of both the leading and subleading terms in the temperature dependence of the inverse static local spin susceptibility at the quantum critical point, calculated using a numerical renormalization-group method, provides evidence that the quantum critical point is interacting in cases where the quantum-to-classical mapping would predict mean-field behavior. The subleading term is shown to be consistent with an \ensuremathω/T scaling of the local dynamical susceptibility, as is the leading term. The frequency and temperature dependences of the local spin susceptibility in the strong-coupling (delocalized) regime are also presented. We attribute the violation of the quantum-to-classical mapping to a Berry-phase term in a continuum path-integral representation of the model. This effect connects the behavior discussed here with its counterparts in models with continuous spin symmetry.