Anomalous Quantum Oscillations in a Heterostructure of Graphene on a Proximate Quantum Spin Liquid
| Autor: | Johannes Knolle, Sananda Biswas, Marko Burghard, Roser Valentí, V. Leeb, K. Polyudov, S. Mashhadi |
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| Rok vydání: | 2021 |
| Předmět: |
Physics
Condensed Matter - Mesoscale and Nanoscale Physics Strongly Correlated Electrons (cond-mat.str-el) Condensed matter physics Mott insulator FOS: Physical sciences General Physics and Astronomy Quantum oscillations Charge (physics) 01 natural sciences Condensed Matter - Strongly Correlated Electrons Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 0103 physical sciences Condensed Matter::Strongly Correlated Electrons Fermi liquid theory Microscopic theory Quantum spin liquid 010306 general physics Spin-½ Majorana fermion |
| Zdroj: | Physical Review Letters. 126 |
| ISSN: | 1079-7114 0031-9007 |
| DOI: | 10.1103/physrevlett.126.097201 |
| Popis: | The quasi two-dimensional Mott insulator $\alpha$-RuCl$_3$ is proximate to the sought-after Kitaev quantum spin liquid (QSL). In a layer of $\alpha$-RuCl$_3$ on graphene the dominant Kitaev exchange is further enhanced by strain. Recently, quantum oscillation (QO) measurements of such $\alpha$-RuCl$_3$ / graphene heterostructures showed an anomalous temperature dependence beyond the standard Lifshitz-Kosevich (LK) description. Here, we develop a theory of anomalous QO in an effective Kitaev-Kondo lattice model in which the itinerant electrons of the graphene layer interact with the correlated magnetic layer via spin interactions. At low temperatures a heavy Fermi liquid emerges such that the neutral Majorana fermion excitations of the Kitaev QSL acquire charge by hybridising with the graphene Dirac band. Using ab-initio calculations to determine the parameters of our low energy model we provide a microscopic theory of anomalous QOs with a non-LK temperature dependence consistent with our measurements. We show how remnants of fractionalized spin excitations can give rise to characteristic signatures in QO experiments. Comment: 4.5 pages, 3 figures, supplementary material included |
| Databáze: | OpenAIRE |
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