Quantum magnetism in minerals
| Thesis title in Czech: | Kvantový magnetismus v minerálech |
|---|---|
| Thesis title in English: | Quantum magnetism in minerals |
| Key words: | kvantové fluktuace|nepružný neutronový rozptyl|minerály|magnetismus |
| English key words: | quantum oscilations|inelastic neutron scattering|minerals|magnetismneutron scattering |
| Academic year of topic announcement: | 2022/2023 |
| Thesis type: | dissertation |
| Thesis language: | angličtina |
| Department: | Department of Condensed Matter Physics (32-KFKL) |
| Supervisor: | RNDr. Petr Čermák, Ph.D. |
| Author: | hidden - assigned and confirmed by the Study Dept. |
| Date of registration: | 02.08.2022 |
| Date of assignment: | 02.08.2022 |
| Confirmed by Study dept. on: | 22.09.2022 |
| Advisors: | Johanna K. Jochum |
| Guidelines |
| 1. research on the topic of spin-1/2 minerals
2. development of the research plan 3. development of the methodology of crystal coalignment using robotic device 4. crystal growth of studied minerals and their co-alignment using robotic device 5. writing proposals to the neutron facilities and conducting experiments there 6. ongoing processing and interpretation of results 7. contribution to the preparation of publications 8. presentation of results at workshops or conferences 9. summarizing the results, writing the dissertation |
| References |
| 1. A.T. Boothroyd. Principles of Neutron Scattering from Condensed Matter. Oxford University Press, 2020.
2. G. Shirane, S. M. Shapiro and J. M. Tranquada. Neutron scattering with a triple-axis spectrometer: basic techniques. Cambridge University Press, 2002. 3. Z. Zhou, Reviews of Modern Physics 89 (2017) 025003 4. C. Wellm et al., Phys. Rev. B 104 (2021) L100420 5. E. Dagotto, et al., Science 271 (1996) 618 6. B. Lake, et al., Nature Phys 6 (2010) 50–55 7. L. Balents, et al., Nature 464 (2010) 199–208 8. T.-H. Han, et al., Nature (London) 492 (2012) 406 9. K. Iida, et al., Phys. Rev. B 101 (2020) 220408 10. H. Yamamoto, et al., Phys. Rev. Mat. 5 (2021) 104405 11. Čermák, P. Czech JUNIOR STAR GAČR Project application + evaluation. figshare (2021) https://doi.org/10.6084/m9.figshare.14256521.v1 and actual publications related to the topic |
| Preliminary scope of work |
| viz anglická verze upoutávky |
| Preliminary scope of work in English |
| Recent developments in the field of modern condensed matter physics show a variety of new material properties based on low dimensional interactions. These compounds such as simple spin chains [3], spin ladders [4] or complex 2D frustrated antiferromagnetic structures [5] play a pivotal role in the newly born field of spintronics and quantum computing. In most of these compounds magnetism is driven by spin-½ ions, usually Cu, which are predicted to favour the creation of the quantum fluctuations [6]. The growth of these materials presents many technical challenges that are not easy to overcome for classical single crystal growth techniques. However, many of these model structures can be found in naturally growing minerals. The search for quantum spin liquids has identified spin-½ Kagome lattices with nearest-neighbour antiferromagnetic Heisenberg coupling as prime candidates for hosting this new state of matter [7]. Herbertsmithite and Kapellasite are showing spin
liquid behaviour down to mK temperatures [8]. Centennialite, a sister compound of Herbertsmithite, has recently been identified as a kagome lattice magnet with an antiferromagnetic bond located in the vicinity of a quantum critical point, making it another mineral with an interesting magnetic ground state [9]. Recently, the compound Henmilite [10] suggested to consist of coupled two-leg ladders showing an unusual antiferromagnetic dome in the phase diagram pointing to the existence of quantum fluctuations has been discovered. Since inelastic neutron scattering is an indispensable tool to investigate the (magnetic) ground states of matter it would be necessary to co-align several hundreds of crystals to create a suitable sample. Such alignment processes can take up to several months and require a lot of manpower. Monoclinic and triclinic crystals are difficult to align by hand and a fully new approach is needed. The student will accomplish this task using the newly constructed state-of-the-art instrument ALSA [11] which will automatize the coalignment process using artificial intelligence. The aim of this thesis is to investigate the magnetic ground states and the critical (quantum) fluctuations accompanying them in naturally grown minerals, after careful co-alignment with ALSA using quasi- and inelastic neutron scattering on the spin-echo spectrometer RESEDA. RESEDA combines the extremely high resolution of spin-echo spectrometers with the possibility for large applied magnetic fields needed to study quantum fluctuations. |