Novel Field Dependence of Thermal Transport in the Stoichiometric Underdoped Cuprate YBa_2Cu_4O_8
Abstract
The thermal conductivity κ of the stoichiometric underdoped cuprate YBa_2Cu_4O8 was measured down to low temperatures in the vortex state. The residual electronic contribution, κ/T as T arrow 0, was found to be finite in zero field and to increase dramatically in the presence of small magnetic fields. This novel field dependence is unexpected from the semi-classical picture of Doppler shifted quasiparticles, and may require a more detailed theory of transport in the mixed state to explain. We extract a quasiparticle velocity anisotropy ratio v_F/v2 from our data, and contrast these results with recent transport measurements in the YBa_2Cu_3O_6+x system.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARD13008S