Spectroscopy of the Kondo Problem in a Box

Ribhu K. Kaul 1, 2, Gergely Zaránd 3, 4, Shailesh Chandrasekharan 1, Denis Ullmo 1, 5, Harold U. Baranger 1

Physical Review Letters 96 (2006) 176802

Motivated by experiments on double quantum dots, we study the problem of a single magnetic impurity confined in a finite metallic host. We prove an exact theorem for the ground state spin, and use analytic and numerical arguments to map out the spin structure of the excitation spectrum of the many-body Kondo-correlated state, throughout the weak to strong coupling crossover. These excitations can be probed in a simple tunneling-spectroscopy transport experiment; for that situation we solve rate equations for the conductance.

  • 1. Duke Physics,
    Duke University
  • 2. Institut fur Theorie der Kondensierten Materie,
    Universität Karlsruhe
  • 3. Research Institute of Physics,
    Technical University Budapest
  • 4. Institut fur Theoretische Feskorperphysik,
    Universitat Karlsruhe
  • 5. Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS),
    CNRS : UMR8626 – Université Paris XI - Paris Sud