2016/05/31 by Yusuke Nishida · 1 citation
Materials Science · Physics and Astronomy · #Condensed matter physics #Coulomb #Dirac fermion #Electron #Functional renormalization group #Graphene #Graphene research and applications #Physics #Quantum and electron transport phenomena #Quantum electrodynamics #Quantum mechanics #Renormalization group #Topological Materials and Phenomena #cond-mat.mes-hall #nucl-th
paper · pdf · doi:10.1103/physrevb.94.085430
published as Phys. Rev. B 94, 085430 (2016) · 7 pages; published version
openalex created_date 2016/06/24 · arxiv created 2016/08/29 · openalex publication_date 2016/08/29 · arxiv updated 2016/08/30 · openalex updated_date 2026/08/06
We develop a field-theoretic approach to massless Dirac fermions in a supercritical Coulomb potential. By introducing an Aharonov--Bohm solenoid at the potential center, the critical Coulomb charge can be made arbitrarily small for one partial-wave sector, where a perturbative renormalization group analysis becomes possible. We show that a scattering amplitude for reflection of particle at the potential center exhibits the renormalization group limit cycle, i.e., log-periodic revolutions as a function of the scattering energy, revealing the emergence of discrete scale invariance. This outcome is further incorporated in computing the induced charge and current densities, which turn out to have power-law tails with coefficients log-periodic with respect to the distance from the potential center. Our findings are consistent with the previous prediction obtained by directly solving the Dirac equation and can in principle be realized by graphene experiments with charged impurities.