Boliasova O. Quantum Dynamical Effects in Two-Component Systems: Antiferromagnets and Two-Band Superconductors

Українська версія

Thesis for the degree of Candidate of Sciences (CSc)

State registration number

0425U000325

Thesis Registration Form

0425U000325.pdf

Applicant for

Specialization

  • 01.04.07 - Фізика твердого тіла

06-10-2025

Specialized Academic Board

Д 26.168.02

Institute of Metal Physics. G.V. Kurdyumov of the National Academy of Sciences of Ukraine

Essay

This dissertation addresses the investigation of quantum phenomena in antiferro-magnets and two-band superconductors. Both classes of materials are considered promis-ing candidates for applications in quantum technologies and next-generation electronics. What unites them is the presence of an additional degree of freedom – in antiferromag-nets, the ability to control chirality, and in superconductors, the utilization of two elec-tronic bands. The longitudinal dynamics of an antiferromagnet are shown to decompose into two distinct channels: (i) the simultaneous excitation or annihilation of two magnons, and (ii) the excitation of one magnon accompanied by the annihilation of another. These channels display different dependencies on temperature and wave vector. For the first time, the mechanisms governing the decay of such two-magnon interaction channels are demonstrated. Furthermore, it is revealed that, under the influence of an external electric field, an-tiferromagnets exhibit an anomalous region in the frequency spectrum and group veloci-ty. Within this regime, strong “friction” effects emerge, resulting in a pronounced reduc-tion of spectral characteristics and a sharp jump in group velocity up to ~300 km/s. Dis-tinct spatial and temporal damping behaviors of right- and left-handed spin waves in-duced by the Aharonov–Casher effect are also established. In addition, the order parameters of the Mo₀.₅₂Re₀.₄₈ alloy have been evaluated from the differential conductance of Ag/Mo₀.₅₂Re₀.₄₈ point contacts. The analysis con-firms the two-band nature of this alloy and validates its suitability as a platform for ex-ploring multiband superconductivity effects.

Read more

Research papers

1. O.O. Boliasova, V.M. Krivoruchko, “Electric-field control of temporal attenuation right-handed and left-handed magnons in antiferromagnets,” Metallophysics and Advanced Technologies, Vol. 47, No. 6, p. 581–594 (2025); https://doi.org/10.15407/mfint.47.06.0581

2. O.O. Boliasova, V.N. Krivoruchko, “Magnonic Aharonov–Casher effect and elec-tric field control of chirality-dependent spin-wave dynamics in antiferromagnets,” Physical Review B, Vol. 111, No. 10, p. 174440-1–10 (2025); https://doi.org/10.1103/PhysRevB.111.174440

3. V. Tarenkov, A. Shapovalov, O. Boliasova, M. Belogolovskii, A. Kordyuk, “Two-band superconductivity in a Mo–Re alloy with an equal concentration of the com-ponents,” Low Temperature Physics, Vol. 47, No. 2, р. 101–105 (2021); https://doi.org/10.1063/10.0003168

4. A.P. Shapovalov, M.O. Belogolovskii, O.O. Boliasova, O.A. Kordyuk, “Binary molybdenum compounds: Promising materials for novel physics of superconduc-tivity and practical application,” Progress in Physics of Metals, Vol. 22, No. 3, р. 352–381 (2021); https://doi.org/10.15407/ufm.22.03.352

5. O.O. Boliasova, V.N. Krivoruchko, “Longitudinal spin dynamics in the Heisen-berg antiferromagnet: Two-magnon excitations,” Ukrainian Journal of Physics, Vol. 65, No. 10, p. 865–874 (2020); https://doi.org/10.15407/ujpe65.10.865

6. O.I. D’yachenko, V.Yu. Tarenkov, O.O. Boliasova, V.M. Krivoruchko, “Reversi-ble effects of instability in tunnel manganite-metal contacts,” Metallophysics and Advanced Technologies, Vol. 40, No. 3, р. 291–299 (2018); https://doi.org/10.15407/mfint.40.03.0291

7. O. Boliasova, V. Krivoruchko, “Two-magnons longitudinal excitations in the Hei-senberg antiferromagnets,” 2019 IEEE 9th International Conference Nanomateri-als: Applications & Properties (NAP), Odessa, Ukraine, 2019, p. 02M26-1–5; https://doi.org/10.1109/nap47236.2019.216954

8. O. Boliasova, V. Krivoruchko, “Electric-field control of magnetization dynamics in antiferromagnets,” 2023 IEEE Nanotechnology Materials and Devices Conference (NMDC), Paestum, Italy, 2023, p. 352; https://doi.org/10.1109/nmdc57951.2023.10343910

9. A. Shapovalov, O. Boliasova, M. Belogolovskii and O. Kalenyuk, “Two-Band/Two-Gap Superconductivity in Molybdenum–Rhenium Alloys,” 2021 IEEE 12th International Conference on Electronics and Information Technologies (ELIT), Lviv, Ukraine, 2021, p. 242–245; https://doi.org/10.1109/ELIT53502.2021.9501131

Read more

Files

Dissertation_BoliasovaOO.pdf

autoreferat-Avtoreferat_BoliasovaOO.pdf

Similar theses

0425U000398

Vasyl M. Sidak

Relaxation Phenomena and Structural Defects in Sodium Bismuth Titanate Crystals

0525U000451

Alina V. Dvornichenko

Self-organisation of adsorbate with formation of nano-sized structures at condensation and apitaxy

0525U000418

Andrii V. Terekhov

The electronic, magnetic and superconducting properties of multifunctional materials based on transition and rare earth elements

0525U000414

Oleh L. Bratus

Electronic processes in nanocomposite films with silicon and metal nanoparticles

0525U000389

Oleksandr S. Oberemok

Mass-spectrometric analysis of phase-structural transformations of nanoscale objects under the action of ion irradiation