We have demonstrated a new, efficient numerical method for solving one and two holes in the antiferromagnetic background. We have explored the influence of two different polarizations of quantum oxygen vibrations on the spacial symmetry of the bound magnetic bipolaron in the context of the t-J model. Electron phonon coupling to transverse polarization stabilizes the bound bipolar state with the d-wave symmetry. The existence of a magnetic background is essential for the formation of a d-wave bipolaron state.

B.04 Guest lecture

COBISS.SI-ID: 2166884In the electronic transport through nanoscopic systems in the Kondo regime is studied. The effects of electron-phonon coupling are investigated. For the internal molecular modes the main effect is supression of local repulsion. For oscillations of molecule between the contacts it is the hybridization which is affected instead. The stability of the two-channel Kondo fixed point arising at the critical value of the electron-phonon coupling is investigated. The vibrational mode is found to soften making the system unstable to perturbations that break the symmetry of the confining potential.

F.02 Acquisition of new scientific knowledge

COBISS.SI-ID: 2162532Entanglement properties of the time evolution of local operators in the Heisenberg picture are characterized using a measure Operator Space Entanglement Entropy (OSEE). The growth of OSEE in temporal dynamics is related to the number of Majorana fermions (index) in initial product operators, furthermore, it diverges logarithmically for infinite-index initial operators with the prefactor given by the number of stationary points in the quasi-particle dispersion relation. This property is connected to the quantum phase transition in the XY model far from the equilibrium.

F.02 Acquisition of new scientific knowledge

COBISS.SI-ID: 2212964We developed a model of birelaxors, i.e., materials that exhibit simultaneously the properties of relaxor ferroelectrics and relaxor ferromagnets. We estimated the magnetic field at which the relaxation of the dielectric polarization is fully suppressed at room temperature. This is a new phenomenon recently discovered at University of Puerto Rico.

B.04 Guest lecture

COBISS.SI-ID: 22720039We have started research of the user online interactions on Web portals within new FP7 project CYBEREMOTIONS, by mapping the data onto bipartite graphs.

B.03 Paper at an international scientific conference

COBISS.SI-ID: 22840103