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Modified Coulomb potential of QED in a strong magnetic field

Sadooghi, N ; Sharif University of Technology | 2007

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  1. Type of Document: Article
  2. Publisher: Sissa Medialab Srl , 2007
  3. Abstract:
  4. The static Coulomb potential of Quantum Electrodynamics is calculated in the presence of a strong magnetic field by computing perturbatively the vacuum expectation value of the corresponding Wilson loop in the lowest Landau level (LLL) approximation. In the LLL, two different regimes of dynamical mass, md yn., can be distinguished. These two regimes are |q2 | ≪ m2 d yn. ≪ |eB| and m2 d yn. ≪ |q2 | ≪ |eB|, where q is the longitudinal components of the momentum relative to the external magnetic field B. As it turns out, the potential in the first regime, |q2 | ≪ m2 d yn. ≪ |eB|, has the general form of a modfied Coulomb potential V1(R, θ ) = −α R A1(α, θ ) −γ A2 R (α 2 ,θ ) + γ 2 A3 (α,θ ) , where α is the fine structure constant and R4 θ the angle between the particle-antiparticle axis and the external magnetic field. In the second regime, m2 d yn. ≪ |q2 | ≪ |eB|, however, the potential has the general form of a modified Yukawa potential V2(R, θ ) = −(1 α − e απ − ) M g eff. (θ R )R with Meff.(α, θ ) ≡ g(θ )2α π |eB| . The θ -dependence of V1 and V2 is a novel property, which was not observed before in the literature. As it turns out, in the regime |q2 | ≪ m2 d yn. ≪ |eB|, for strong enough magnetic field and depending on the angle θ , a qualitative change occurs in the Coulomb-like potential V1; Whereas for θ = 0, π the potential is repulsive, it exhibits a minimum for angles θ ∈]0, π [. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence
  5. Keywords:
  6. Computation theory ; Coulomb blockade ; Electric fields ; Electrodynamics ; Magnetic fields ; Quantum electronics ; Expectation values ; External magnetic field ; Fine structure constants ; Longitudinal components ; Lowest-Landau level approximations ; Qualitative changes ; Quantum electrodynamics ; Strong magnetic fields ; Lattice theory
  7. Source: 25th International Symposium on Lattice Field Theory, LATTICE 2007, 30 July 2007 through 4 August 2007 ; Volume 42 , 2007 ; 18248039 (ISSN)
  8. URL: https://www.researchgate.net/publication/323021427_Modified_Coulomb_potential_of_QED_in_a_strong_magnetic_field