Nernst Coefficient and Magnetoresistance in High-Tc Superconductors: The Role of Superconducting Fluctuations

Hiroshi Kontani

doi:10.1103/PhysRevLett.89.237003

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Nernst Coefficient and Magnetoresistance in High-Tc Superconductors: The Role of Superconducting Fluctuations

Hiroshi Kontani

DOI 10.1103/PhysRevLett.89.237003 · Physical Review Letters

T1

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Abstract

In high-Tc cuprates, the Nernst coefficient (ν) as well as the magnetoresistance (Δρ/ρ) increases drastically below the pseudogap temperature, T*, which attracts much attention as a key phenomenon in the pseudogap region. We study these transport phenomena in terms of the fluctuation−exchange+T–matrix approximation. In this present theory, the d-wave superconducting (SC) fluctuations, which are mediated by antiferromagnetic (AF) correlations, become dominant below T*. We especially investigate the vertex corrections both for the charge current and the heat one to keep the conservation laws. As a result, the mysterious behaviors of ν and Δρ/ρ are naturally explained as the reflection of the enhancement of the SC fluctuation, without assuming thermally excited vortices. The present result suggests that the pseudogap phenomena are well described in terms of the Fermi liquid with AF and SC fluctuations.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
La2-xSrxCuO4 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown