Spin Kondo Physics in Quantum Dot Systems

Kondo resonances in two adjacent Coulomb blockade regions of a quantum dot system, not expected from the constant interaction model.

© MPI-FKF / J. Schmid


The degree of freedom occupying a quantum dot by either a spin-up or spin-down electron – both states are energetically degenerated - can give rise to a peculiar quantum dynamical effect described in the framework of Kondo physics: Correlated electron tunneling between quantum dot and leads cause the formation of a spin-singlet state where the electron spin on the quantum dot fluctuates between both orientations, always screened by the spins of the electrons in the leads. A correlated many-electron state is formed outreaching a certain distance from the quantum dot into the leads. In consequence, although the quantum dot system shows pronounced Coulomb blockade at elevated temperature, it becomes highly conductive with lowering the temperature.


Publications

A quantum dot in the limit of strong coupling to reservoirs
J. Schmid, J. Weis, K. Eberl, K. von Klitzing
Physica B 256, 182 (1998)

Kondo resonances in split-gate quantum dots
J. Schmid, J. Weis, K. Eberl
Physica E 6, 375 (2000)

Absence of odd-even parity behavior for Kondo resonances in quantum dots
J. Schmid, J. Weis, K. Eberl, K. von Klitzing
Physical Review Letters 84, 5824 (2000)

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

Kondo physics on single and electrostatically coupled quantum dots
J. Weis, J. Schmid, U. Wilhelm, M. Keller
Springer Proceedings in Physics 87, 1013 (2001)

Theses

The Kondo Effect in Quantum Dots
Jörg Schmid, Dissertation, Universität Stuttgart (2000)

A Quantum Dot with Three Leads: Tunnel Spectroscopy in the KONDO and the FANO Regime;
a Single-Electron-Transistor with Current Gain

Armin Welker, Dissertation, Universität Stuttgart (2007)

Annual Reports

Kondo physics in electrical transport through a quantum dot system (pdf)
J. Schmid, J. Weis, K. von Klitzing, K. Eberl (1998)

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