Kondo effect in nanostructures

The Kondo effect is an unusual scattering mechanism of conduction electrons in a metal due to magnetic impurities, which contributes a term to the electrical resistivity that increases logarithmically with temperature as the temperature T is lowered. The Kondo effect can be considered as an example of asymptotic freedom, i.e. a situation where the coupling becomes non-perturbatively strong at low temperatures and low energies. In the Kondo problem, the coupling refers to the interaction between the localized magnetic impurities and the itinerant electrons.

It is sometimes used more generally to describe many-body scattering processes from impurities or ions which have low energy quantum mechanical degrees of freedom. In this more general sense it has become a key concept in condensed matter physics in understanding the behavior of metallic systems with strongly interacting electrons. Many of the basic concepts and notions of the field have either been conceived or signicantly advanced in the context of Kondo physics.


During the last decades, novel experimental advances in transport through nanostructures have renewed the interest in the Kondo effect. Such advances allow the precise control of the microscopic model parameters in combination with the capabilities of detailed sample engineering. Our group, in particular, studies various aspects of the Kondo effect in various nanostructures including quantum-dot devices, nanotubes, single dopants in silicon, etc.


Selected publications

Odd and even Kondo effects from emergent localization in quantum point contacts
Iqbal, MJ; Roi, L; Koop, EJ; Dekker, JB; de Jong, JP; van der Velde, JHM; Reuter, D; Wieck, AD; Aguado, R; Meir Y; van der Wal, CH
Nature 501, 79 (2013)

Magnetic-Field Probing of an SU(4) Kondo Resonance in a Single-Atom Transistor, G. C. Tettamanzi, J. Verduijn, G. P. Lansbergen, M. Blaauboer, M. J. Calderón, R. Aguado, and S. Rogge
Phys. Rev. Lett. 108, 046803 (2012)

Two-impurity Anderson model revisited: Competition between Kondo effect and reservoir-mediated superexchange in double quantum dots
Minchul Lee, Mahn-Soo Choi, Rosa López, Ramón Aguado, Jan Martinek, and Rok Žitko
Phys. Rev. B 81, 121311(R) (2010)

SU(4) Kondo Effect in Carbon Nanotubes
Manh-Soo Choi, Rosa López, and Ramón Aguado
Phys. Rev. Lett. 95, 067204 (2005)