Niskotemperaturowe badania własności fizycznych oraz wpływ domieszek na stan podstawowy Ce3Ru4Sn13 z silnymi korelacjami elektronowymi

Abstract

Experimental and theoretical studies of strong electronic correlations have led to the discovery of fascinating collective quantum phenomena, what still motivates to perform researches in solid state physics and generally induces the development of modern science and technology. Emergent quantum states appear in macroscopic physical experiments, and led to the discovery and explanation of Kondo effect [1], heavy-fermion states [2], superconductivity [3], and even high-temperature superconductivity [4]. The doctoral dissertation is a guidebook through the three scientific publications. Dissertation proves the truth of the thesis: "Atomic disorder, local electronic disorder, inhomogeneity and structural distortion of heavy fermionic compounds with strongly correlated electrons determine the occurrence and dynamics of phase states and ground state properties.", through careful analysis of experimental data. To confirm thesis data from advanced physical experiments such as x-ray diffraction (XRD), magnetic susceptibility and temperature magnetization studies, thermal and electronic transport studies at low and ultra-low temperature (up to 350 mK) also in strong magnetic fields, and electronic structure research has been analyzed. The results description and conclusions were based on advanced calculation methods for the electronic structure simulations based on the density functional theory (DFT) and on Anderson's theoretical model. For the purposes of research, the computer program "DISTorX" [5] was created to simulate charge order of the Charge Density Wave state and the structural distortion; directly visible on X-ray diffraction patterns. Generally the created program is universal enough that it can be successfully applied to a variety of structures. Ce3Ru4Sn13 compound allows us to study surprisingly many physical phenomena’s such as Kondo effect, quantum phase transition, superstructure occurrence, superconductivity, electron correlations or rattling effect.