Shubnikov de Haas effect in the metallic state of Na${}_{0.3}$CoO${}_2$

Abstract

Shubnikov de Haas oscillations for two well defined frequencies, corresponding respectively to areas of 0.8 and 1.36% of the first Brillouin zone (FBZ), were observed in single crystals of Na${}_{0.3}$CoO${}_2$. The existence of Na superstructures in Na${}_{0.3}$CoO${}_2$, coupled with this observation, suggests the possibility that the periods are due to the reconstruction of the large Fermi surface around the $\hat{I}“$ point. An alternative interpretation in terms of the long sought-after $\hat{I}{\mu }_g^{\prime }$ pockets is also considered but found to be incompatible with existing specific heat data.

5 pages 4 figures