News and Research Highlights

Molecules and the graph theory

20 May 2017, 20:35
source: The Journal of Chemical Physics

Ruda Sýkora and Tomáš Novotný present a method based on graph theory for the evaluation of the inelastic propensity rules for molecules exhibiting complete destructive quantum interference in their elastic transmission. The method can be fully automated and they provide a functional website running a code using Wolfram Mathematica which allows everyone to examine their molecules.

Superconducting quantum dot: symmetric vs. asymmetric

18 May 2017, 16:50
source: Martin Žonda

A. Kadlecová and her mates studied the Anderson single-level quantum dot attached to two BCS superconducting leads. They revealed that a system with asymmetric tunnel coupling to the leads can be related to the symmetric one. Surprisingly, it is the symmetric case which is the most general, meaning that all physical quantities in the case of asymmetric coupling are fully determined by the symmetric ones.

Interplay between correlation effects and electron pairing

7 Jan 2017, 10:55
source: Physical Review B

T. Domański et al. studied subgap spectrum of the interacting single-level quantum dot coupled between two superconducting reservoirs, forming the Josephson-type circuit, and additionally hybridized with a metallic normal lead. They quantitatively establish the phase-dependent Kondo temperature and show that it can be read off from the half-width of the zero-bias enhancement in the Andreev conductance in the doublet phase.

Stoner versus Heisenberg

7 Jan 2017, 10:45
source: Physical Review B

E. Turgut et al. use ultrafast high harmonics to measure time-, energy-, and angle-resolved M-edge magnetic asymmetry spectra for Co films after optical pumping to induce ultrafast demagnetization. They found that the magnon contribution to ultrafast demagnetization is already strong on subpicosecond time scales, while the reduction in exchange splitting persists to several picoseconds.

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