The search for quantum spin liquids (QSLs) introduces some of the most challenging and interesting problems in contemporary physics. The recently discovered iridate Cu2IrO3,which contains a honeycomb lattice of Ir4+ions with effective spin 1/2 coupled by frustrated Ising interactions, presents itself as a promising candidate for a Kitaev QSL. In this study, we use nuclear magnetic resonance (NMR), a spectroscopic technique based on the energy levels of nuclear spin states, to probe the intrinsic spin excitations of Cu2IrO3. By measuring the NMR frequency shift of 63Cu from 4.2 K to 298 K,we demonstrate that its spin susceptibility χ spin behaves nearly identically to its parent compound Na2IrO3, without showing evidence of magnetic ordering at low temperatures. We showed that the upturn of bulk susceptibility χ below T=50 K is due to the contribution of defect spins. The hyperfine coupling constant Ahf between Cu and Ir4+was also estimated by comparing the Knight shift 63K to χ / Thesis / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/25060 |
| Date | January 2019 |
| Creators | Wang, Jiaming |
| Contributors | Imai, Takashi, Physics and Astronomy |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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