We revisit the Aslamazov-Larkin theory of paraconductivity in two dimensions to identify its universal and its specific model-dependent features. We show that both the numerical prefactor and the temperature dependence of the experimental paraconductivity in underdoped La(2-x)Sr(x)CuO(4) provide evidence that the paired carriers behave as if they were nearly free fermionic quasiparticles. This conclusion is strengthened by the analysis of paraconductivity data in the presence of a finite magnetic field. In this case we show that there exists a temperature range above T(c) where the superconducting fluctuations are purely Gaussian and their destruction is determined by a rather low magnetic field scale H(c2)(G)(T=0).
Paraconductivity in layered cuprates behaves as if due to pairing of nearly free quasiparticles / Caprara, Sergio; Grilli, Marco; B., Leridon; J., Vanacken. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 79:2(2009), pp. 024506:1-024506:7. [10.1103/physrevb.79.024506]
Paraconductivity in layered cuprates behaves as if due to pairing of nearly free quasiparticles
CAPRARA, SERGIO;GRILLI, Marco;
2009
Abstract
We revisit the Aslamazov-Larkin theory of paraconductivity in two dimensions to identify its universal and its specific model-dependent features. We show that both the numerical prefactor and the temperature dependence of the experimental paraconductivity in underdoped La(2-x)Sr(x)CuO(4) provide evidence that the paired carriers behave as if they were nearly free fermionic quasiparticles. This conclusion is strengthened by the analysis of paraconductivity data in the presence of a finite magnetic field. In this case we show that there exists a temperature range above T(c) where the superconducting fluctuations are purely Gaussian and their destruction is determined by a rather low magnetic field scale H(c2)(G)(T=0).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
