Quantum Dot System in High Magnetic Fields: Chess Board Pattern of Kondo-Correlated States

Regular, chessboard-like occurrence of Kondo states with changing the applied magnetic flux density and number of confined electrons in a quantum dot, exposed to a high magnetic field. © MPI-FKF / M. Keller

Quantum dots – defined in a two-dimensional electron system – show in high magnetic fields a peculiar internal electronic structure of ring-like electrically compressible and incompressible regions, formed by the interplay of the applied magnetic field flux density and electron-electron interaction. Such compressible and incompressible stripes in the depletion region of two-dimensional electron systems play also a key role in understanding the current distribution in quantum Hall samples.

As a function of gate voltage (changing the number of electrons in the quantum dot) and applied magnetic field, a systematic rearrangement of electrons within the quantum dot happens, manifesting itself in a very regular, chessboard-like occurrence of enhanced conductance due to the formation of Kondo-correlated states with the leads.

Publications

Split Kondo resonances in quantum dots at finite magnetic fields
J. Schmid, J. Weis, K. Eberl, K. von Klitzing
Physica E 9, 54 (2001)

Quantum dot in high magnetic fields: Correlated tunneling of electrons probes the spin configuration at the edge of the dot
M. Keller, U. Wilhelm, J. Schmid, J. Weis, K. von Klitzing, K. Eberl
Physical Review B 64, 3 (2001)

Theses

Der Kondo-Effekt in Quantendots bei hohen Magnetfeldern
Matthias Keller, Dissertation, Universität Stuttgart (2001)

Magneto-electrical transport through MBE-grown III-V semiconductor nanostructures: from zero- to one-dimensional type of transport
Eleonora Storace, Dissertation, Universität Stuttgart (2009)