Low-energy electrodynamics of novel spin excitations in the quantum spin ice Yb2Ti2O7
Résumé
In condensed matter systems, formation of long-range order (LRO) is often accompanied by new excitations. However, in many geometrically frustrated magnetic systems, conventional LRO is suppressed, while non-trivial spin correlations are still observed. A natural question to ask is then what is the nature of the excitations in this highly correlated state without broken symmetry? Frequently, applying a symmetry breaking field stabilizes excitations whose properties reflect certain aspects of the anomalous state without LRO. Here we report a THz spectroscopy study of novel excitations in quantum spin ice Yb 2 Ti 2 O 7 under a o0014 directed magnetic field. At large positive fields, both right-and left-handed magnon and twomagnon-like excitations are observed. The g-factors of these excitations are dramatically enhanced in the low-field limit, showing a crossover of these states into features consistent with the quantum string-like excitations proposed to exist in quantum spin ice in small o0014 fields.
Domaines
Physique [physics]
Fichier principal
Pan et al. - 2014 - Low-energy electrodynamics of novel spin excitations in the quantum spin ice Yb2Ti2O7.pdf (582.54 Ko)
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