Thermal Hall Effect of Spin Excitations in a Kagome Magnet.
Phys Rev Lett
; 115(10): 106603, 2015 Sep 04.
Article
em En
| MEDLINE
| ID: mdl-26382691
ABSTRACT
At low temperatures, the thermal conductivity of spin excitations in a magnetic insulator can exceed that of phonons. However, because they are charge neutral, the spin waves are not expected to display a thermal Hall effect. However, in the kagome lattice, theory predicts that the Berry curvature leads to a thermal Hall conductivity κ(xy). Here we report observation of a large κ(xy) in the kagome magnet Cu(1-3, bdc) which orders magnetically at 1.8 K. The observed κ(xy) undergoes a remarkable sign reversal with changes in temperature or magnetic field, associated with sign alternation of the Chern flux between magnon bands. The close correlation between κ(xy) and κ(xx) firmly precludes a phonon origin for the thermal Hall effect.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Phys Rev Lett
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Estados Unidos