Large spin-wave energy gap in the bilayer iridate Sr3Ir2O7: Evidence for enhanced dipolar interactions near the Mott metal-insulator transition
Publikation: Beitrag in Fachzeitschrift › Forschungsartikel › Beigetragen › Begutachtung
Beitragende
Abstract
Using resonant inelastic x-ray scattering, we observe in the bilayer iridate Sr 3Ir 2O 7, a spin-orbit coupling driven magnetic insulator with a small charge gap, a magnon gap of ∼92meV for both acoustic and optical branches. This exceptionally large magnon gap exceeds the total magnon bandwidth of ∼70meV and implies a marked departure from the Heisenberg model, in stark contrast to the case of the single-layer iridate Sr 2IrO 4. Analyzing the origin of these observations, we find that the giant magnon gap results from bond-directional pseudodipolar interactions that are strongly enhanced near the metal-insulator transition boundary. This suggests that novel magnetism, such as that inspired by the Kitaev model built on the pseudodipolar interactions, may emerge in small charge-gap iridates.
Details
Originalsprache | Englisch |
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Aufsatznummer | 157402 |
Fachzeitschrift | Physical review letters |
Jahrgang | 109 |
Ausgabenummer | 15 |
Publikationsstatus | Veröffentlicht - 10 Okt. 2012 |
Peer-Review-Status | Ja |
Extern publiziert | Ja |