Vendredi 05 juillet 2013 à 14h35
Auditoire Stueckelberg, Ecole de Physique

Unconventional superconductivity in double quantum dots

Björn Sothmann, Université de Genève

Conventional superconductivity is well described by BCS theory which explains the occurrence of superconductivity by the formation of spin-singlet Cooper pairs. However, other unconventional superconducting correlations exist as well which exhibit, e.g., a spin-triplet character and/or describe an odd-frequency pairing [1,2]. Here, we demonstrate that all types of superconductivity can be induced in a double quantum dot coupled to an s-wave superconductor and subject to an inhomogenous, noncollinear magnetic field. We introduce suitable order parameters to characterize the unconventional superconducting correlations. We, furthermore, discuss the conditions necessary to generate the different types of correlations. We conclude by demonstrating how to detect unconventional superconductivity in the transport properties of the double dot. [1] Berezinskii, JETP Letters 20, 287 (1974). [2] Bergeret, Volkov, Efetov, Rev. Mod. Phys. 77, 1321 (2005). [3] Sothmann, Weiss, Governale, K"onig, in preparation.