Superconducting Proximity Effect in Quantum Dots

• Applicants: Professor Dr. Jürgen König; Dr. Stephan Weiß
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2011 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 193403257

Well-defined and -controllable nanostructures such as quantum dots are ideal model systems to investigate the interplay of Coulomb interaction, nonequilibrium, and collective order. We study theoretically electronic transport through systems containing interacting quantum dots coupled to superconducting leads. Superconducting correlations are induced on the quantum dots by the equilibrium and nonequilibrium proximity effect and can be manipulated via gate and bias voltages. They affect the transport characteristics, e.g., of the Josephson or the local and the nonlocal Andreev currents. For hybrid systems involving noncollinear magnetism, unconventional superconducting pairing can be induced. The main objective of the present project is to develop and apply theoretical tools that properly take into account the important role played by Coulomb interaction in the quantum dot. We will identify for various device geometries signatures of the induced conventional and unconventional superconducting correlations in transport quantities such as the current and the current noise.

• DFG Programme: Research Grants