arXiv subjects

G. Gorski

Publications and source records attributed to G. Gorski.

3 recordsLinked to original sources

arXiv2018

Kondo and Majorana signatures near the singlet-doublet quantum phase transition

We study the low energy spectrum of a correlated quantum dot embedded between the normal conducting and superconducting reservoirs and hybridized with the topological superconducting nanowire, hosting the Majorana end-modes. We investigate the leaking Majorana quasiparticle and inspect its interplay with the proximity induced on-dot pairing and correlations. In particular, we focus on the subgap Kondo effect near the quantum phase transition/crossover from the spinfull (doublet) to the spinless (BCS-type singlet) configurations. Treating the correlations perturbatively and within the NRG approach we study its signatures observable in the Andreev (particle-to-hole conversion) tunneling spectroscopy. We find, that the leaking Majorana mode has a spin-selective influence on the subgap Kondo effect.

cond-mat.str-el↗

arXiv2018

Interplay between pairing and correlations in spin-polarized bound states

We investigate the single and multiple defects embedded in a superconducting host, studying interplay between the proximity induced pairing and interactions. We explore influence of the spin-orbit coupling on energies, polarization and spatial patterns of the bound (Yu-Shiba-Rusinov) states of magnetic impurities in 2-dimensional square lattice. We also address the peculiar bound states in the proximitized Rashba chain, resembling the Majorana quasiparticles, focusing on their magnetic polarization which has been recently reported by S. Jeon et al., [Science 358, 772 (2017)]. Finally, we study leakage of these polarized Majorana quasiparticles on the side-attached nanoscopic regions and confront them with the subgap Kondo effect near to the singlet-doublet phase transition.

cond-mat.mes-hall↗

arXiv2015

Constructive influence of the induced electron pairing on the Kondo state

Superconductivity and magnetism are usually the conflicting (competing) phenomena. We show, however, that in nanoscopic objects the electron pairing may promote the magnetic ordering. Such situation is possible at low temperatures in the quantum dots placed between the conducting and superconducting reservoirs, where the proximity induced electron pairing cooperates with the correlations enhancing the spin-exchange interactions. The emerging Kondo resonance, which is observable in the Andreev conductance, can be significantly enhanced by the coupling to superconducting lead. We explain this intriguing tendency within the Anderson impurity model using: the generalized Schrieffer-Wolff canonical transformation, the second order perturbative treatment of the Coulomb repulsion, and the nonperturbative numerical renormalization group calculations. We also provide hints for experimental observability of this phenomenon.

cond-mat.supr-con↗