Compressive strain induced enhancement of exchange interaction and short-range magnetic order in Sr2IrO4 investigated by Raman spectroscopy
| Autor: | Maryam Souri, Hae-Young Kee, Matteo Minola, J. G. Connell, Ambrose Seo, Bernhard Keimer, K. Fürsich, Hlynur Gretarsson, P. Peter Stavropoulos, Hyun-Taek Kim |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Condensed matter physics Mott insulator Exchange interaction 02 engineering and technology Atmospheric temperature range 021001 nanoscience & nanotechnology 01 natural sciences Condensed Matter::Materials Science symbols.namesake Superexchange 0103 physical sciences symbols Antiferromagnetism Condensed Matter::Strongly Correlated Electrons Density functional theory 010306 general physics 0210 nano-technology Raman spectroscopy Energy (signal processing) |
| Zdroj: | Physical Review B. 100 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | We have carried out Raman spectroscopy experiments to investigate two-magnon excitations in epitaxial thin films of the quasi-two-dimensional antiferromagnetic Mott insulator $\mathrm{S}{\mathrm{r}}_{2}\mathrm{Ir}{\mathrm{O}}_{4}$ under in-plane misfit strain. With in-plane biaxial compression, the energy of the two-magnon peak increases and the peak remains observable over a wider temperature range above the N\'eel temperature, indicating a strain-induced enhancement of the superexchange interactions between ${J}_{\mathrm{eff}}=1/2$ pseudospins. From density functional theory calculations, we have found an increase of the nearest-neighbor hopping parameter and exchange interaction with increasing biaxial compressive strain, in agreement with the experimental observations. Our experimental and theoretical results provide perspectives for systematic, theory-guided strain control of the primary exchange interactions in $5d$ transition-metal oxides. |
| Databáze: | OpenAIRE |
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