News (1 Aug 2014 - 15 Oct 2016)

Exchange and spin-orbit induced phenomena in (Ga,Mn)As

added on 15 October 2016, 16:00

Physical properties induced by exchange interactions and spin-orbit coupling in the diluted (Ga,Mn)As ferromagnetic semiconductor are studied from first principles by J. Kudrnovský, V. Drchal, and I. Turek. Their calculations based on recently developed Kubo-Bastin transport theory. Good agreement of calculated physical quantities with experiment was obtained.

Electronic transport in Bi2Te3

added on 16 August 2016, 9:00

K. Carva et al. published a first-principles study of the electronic, magnetic, and transport properties of the 3D topological insulator Bi2Te3 doped with Mn atoms in substitutional and interstitial van der Waals gap positions. Their calculations indicate that for explanation of experimental observations the role of interstitials may be more important than expected.

The paper was selected for Phys. Rev. B Kaleidoscope in June 2016.

Perturbation theory for an Anderson QD

added on 7 February 2016, 15:43

Anderson quantum dot was studied by M. Žonda et al. by means of perturbation expansion to the second order. They suggest that in some cases the heavy numerical tools such as numerical renormalization group or quantum Monte Carlo can be safely replaced by a perturbative approach with less computational demands.

Quantum Mechanics I.

added on 7 February 2016, 13:03

First part of a new textbook by J. Klíma and B. Velický on quantum mechanics in Czech language will appear soon. The book is an introduction to nonrelativistic quantum mechanics supported by number of examples.

source: Karolinum

New research project

added on 3 December 2015, 20:25

T. Novotný successfully received a research grant on study of vibrational effects in nonequilibrium electronic transport through nanosystems. The project, which starts on 1st January 2016, will last for 3 years.

Magnetic properties of Mn-doped Bi2Se3

added on 2 December 2015, 22:50

R. Tarasenko et al. studied magnetic and structural properties of Mn-doped Bi2Se3 topological insulators grown by molecular beam epitaxy. The exchange interaction between the Mn moments leads to a ferromagnetic phase at low temperatures with a roughly linear relation between the Curie temperature and the atomic concentration of Mn.

Disparate ultrafast dynamics in Gadolinium

added on 11 September 2015, 19:45

Gadolinium shows disparate dynamics of the localized 4f and the itinerant 5d spin moments, demonstrating a breakdown of their intra-atomic exchange alignment on a picosecond timescale.

Superconducting 0-Pi impurity quantum phase transition

added on 17 March 2015, 18:00

M. Žonda et al present results for phase diagrams, level occupation, induced local superconducting gap, Josephson current, and energy of the Andreev bound states with the precision surpassing any (semi)analytical approaches employed thus far.

Ultrafast spintronics: Give it a whirl

added on 1 August 2014, 19:40

Measurements of laser-induced magnetization dynamics suggest that spin currents can be generated on ultrafast timescales. Now it is shown that such currents may be capable of exerting ultrafast spin-transfer torques.