Wiedemann-Franz law in the underdoped cuprate superconductor YBa2Cu3Oy

Article

关键词: UPPER CRITICAL-FIELD;    DENSITY-WAVE ORDER;    QUANTUM OSCILLATIONS;    FERMI-SURFACE;    CHARGE ORDER;    STRIPE ORDER;    ENHANCEMENT;   

DOI  :  10.1103/PhysRevB.93.064513

来源: SCIE

【 摘 要 】

The electrical and thermal Hall conductivities of the cuprate superconductor YBa2Cu3Oy, sigma(xy) and kappa(xy), were measured in a magnetic field up to 35 T, at a hole concentration (doping) p = 0.11. In the T = 0 limit, we find that the Wiedemann-Franz law, kappa(xy)/T = (pi(2)/3)(k(B)/e)(2)sigma(xy), is satisfied for fields immediately above the vortex-melting field H-vs. This rules out the existence of a vortex liquid at T = 0 and it puts a clear constraint on the nature of the normal state in underdoped cuprates, in a region of the doping phase diagram where charge-density-wave order is known to exist. As the temperature is raised, the Lorenz ratio, L-xy = kappa(xy)/(sigma T-xy), decreases rapidly, indicating that strong small-q scattering processes are involved.

【 授权许可】

Free