arXiv subjects

E. A. Tereshina-Chitrova

Publications and source records attributed to E. A. Tereshina-Chitrova.

4 recordsLinked to original sources

arXiv2026

Photoelectron Spectroscopy Study of U-Te Thin Films: A Unified Perspective of Hybridization Effects across Compositions

Uranium tellurides span magnetic and superconducting ground states, yet systematic electronic-structure information across the U-Te series remains scarce. In this study, we perform photoemission measurements on freshly prepared UxTey thin films covering the range of bulk stoichiometries under ultra-high vacuum (10^-9 Pa), enabling clean surfaces and compositions matching bulk phases, including the celebrated UTe2. X-ray and ultraviolet photoelectron spectroscopy (XPS/UPS) reveal consistent evolution of the U 4f and Te 3d core levels and valence states across the series, in good agreement with the limited bulk data. Supported by uniform ab initio calculations for all U-Te compounds, we identify systematic trends in U-Te hybridization and charge-transfer effects across the series. These results establish thin-film photoemission as a reliable route for mapping electronic-structure trends in tellurides of heavy elements with diverse electronic ground states.

cond-mat.mtrl-sci↗

arXiv2024

High-field ultrasound study of elastic constants and possible magnetic symmetry transformations in UO2

In this study, we probe the coupling between magnetism and lattice dynamics in UO2, a 3k antiferromagnet that undergoes magnetic ordering below its Neel temperature (TN) of 30.8 K. Ultrasound measurements provide insights into the interplay between the material's magnetic properties and lattice vibrations in response to the applied high magnetic field. A model analysis based on ab initio calculated superexchange interactions predicts a change in the magnetic structure from 3k to 2k at around 50 T. Although this change is not evident in the magnetization curve, we observe a crossover of ultrasound velocity Dv/v using a phase-sensitive pulse-echo technique in pulsed magnetic fields of up to 65 T. We show that at Hz > 50 T, the structure remains antiferromagnetic in the (x, y) plane and becomes ferromagnetic in the z direction. A further transition into the 1k structure is theoretically predicted to take place at a magnetic field of ~104 tesla.

cond-mat.str-el↗

arXiv2023

Strain-driven switching between antiferromagnetic states in frustrated antiferromagnet UO2 probed by exchange bias effect

Frustrated antiferromagnets offer a captivating platform to study the intricate relationship of magnetic interactions, geometric constraints, and emergent phenomena. By controlling spin orientations, these materials can be tailored for applications in spintronics and quantum information processing. The research focuses on the interplay of magnetic and exchange anisotropy effects in artificial heterostructures based on a canonical frustrated antiferromagnet, UO2. The potential to manipulate the spin directions in this material and switch between distinct antiferromagnetic states is investigated using substrate-induced strain. The phenomenon is probed using exchange bias (EB) effects in stoichiometric UO2/Fe3O4 bilayers. By employing many-body first-principles calculations magnetic configurations in the UO2 layers are identified. Even a minor tetragonal distortion triggers a transition between antiferromagnetic states of different symmetries, driven by a robust alteration of single-ion anisotropy due to the distortion. Consequently, this change influences the arrangement of magnetic moments at the UO2/Fe3O4 interface, affecting the magnitude of exchange bias. The findings showcase how epitaxial strain can effectively manipulate the antiferromagnetic states in frustrated antiferromagnets by controlling single-site anisotropy.

cond-mat.mtrl-sci↗

arXiv2022

Structure of the normal state and origin of Schottky anomaly in the correlated heavy fermion superconductor UTe2

The newly discovered UTe2 superconductor is regarded as a heavy fermion mixed-valence system with very peculiar properties within the normal and superconducting states. It shows no signs of magnetic order but strong anisotropy of a magnetic susceptibility and a superconducting critical field. In addition to the heavy fermion-like behavior in the normal state, it exhibits also a distinctive Schottky-type anomaly at about 12 K and a characteristic excitations gap ~35-40 K. Here we show, by virtue of dynamical mean-field theory calculations with a quasi-atomic treatment of electron correlations, that ab-initio derived crystal-field splitting of the 5f2 ionic configuration yields an agreement with these experimental observations. We analyze the symmetry of magnetic and multipolar moment fluctuations that might lead to the superconducting pairing at low temperatures. A close analogy of the normal paramagnetic state of UTe2 to that of URu2Si2 in the Kondo arrest scenario is revealed.

cond-mat.supr-con↗