April 2021

It is the end of the third quarter of our project implementation. In the last three months our computational cluster got fully upgraded. We have developed several new codes that are already put into production. Mihailo Čubrović has found a promising AdS model that appears to capture
the single-particle propagator for the Hubbard model in a wide range of parameters. The mixed-basis method developed by Veljko Janković is know fully benchmarked and is already allowing access to lattice sizes that cannot be treated with the Lanczos method. Ivana Vasić has implemented the Gutzwiller method and is already producing results for the optical conductivity in the bosonic Hubbard model. Jakša Vučičević has completed the work on the Hubbard model in magnetic field using DMFT, which led to two new preprints on arxiv.

We are pleased to announce that the most recent work by Jakša Vučičević and Rok Žitko is now available on arXiv, in the form of a short paper “Universal magnetic oscillations of conductivity in the incoherent regime of correlated systems” and a long accompanying paper “Conductivity in the Hubbard model: orbital effects of magnetic field“. The two papers document in detail the DMFT solution for the conductivity in the square-lattice Hubbard model. In the regime of moderate incoherence of the electrons, the conductivity displays quantum oscillations which are fundamentally different from the conventional Shubnikov-de Haas (SdH) oscillations. This result presents a striking example of interplay between strong magnetic fields and electronic correlations, and is likely to motivate further experimental and theoretical research

We are happy to anounce that the recent work by Jakša Vučičević, Pavle Stipsić and Michel Ferrero has been published in Physical Review Research. The paper presents an analytical solution of the imaginary time integrals that appear in quantum many-body perturbation theory, and its application in the study of the two-dimensional Hubbard model using diagrammatic Monte Carlo algorithms.

Today we have recorded a short presentation of our project to appear in an episode of “Nauka privredi” program on RT Vojvodina (YouTube channel: https://www.youtube.com/channel/UCHKY27-sW5C5WI9J9sEwudA).