High magnetic fields and the correlation gap in SmB{sub 6}
- Univ. of Michigan, Ann Arbor, MI (United States)
- Los Alamos National Lab., NM (United States); and others
The authors report the results of electrical resistivity measurements on SmB{sub 6} in magnetic fields as large at 18 T and pressures as large at 66 kbar. They find that the activation gap {Delta} has an anomalously weak field dependence, even when pressures of {approximately}50kbar are used to tune {Delta} to instability. Their results imply the existence of strong exchange interactions in the low pressure, gapped state, and argue that {Delta} originates with many electron correlations. Nonetheless, the small negative magnetoresistance {Delta}/{rho}(H)/{rho}(H = 0) {proportional_to} H{sup 2} observed below 50 kbar is completely accounted for by the weak field variation of {Delta}. A sign change in the magnetoresistance accompanies the gap collapse, with the high pressure gapless metal having {Delta}/{rho}(H)/{rho}(H = 0) {proportional_to} H{sup 3/2}. The Fermi surface deduced from these measurements is similar to that of noninteracting trivalent LaB{sub 6}, but with a volume which increases rapidly with pressure.
- OSTI ID:
- 425965
- Report Number(s):
- CONF-9505186--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Magnetic field dependence of the correlation gap in SmB{sub 6}
SmB[sub 6]: Kondo insulator or exotic metal