TY - JOUR

T1 - Coherence effect in a two-band superconductor

T2 - Application to iron pnictides

AU - Masuda, Keisuke

AU - Kurihara, Susumu

PY - 2010/7

Y1 - 2010/7

N2 - From a theoretical point of view, we propose an experimental method to determine the pairing symmetry of iron pnictides. We focus on two kinds of pairing symmetries, s+- and s++, which are strong candidates for the pairing symmetry of iron pnictides. For each of these two symmetries, we calculate both the density and spin response functions by using the two-band BCS model within the one-loop approximation. As a result, a clear difference is found between the s+- and s++-wave states in the temperature dependence of the response functions at nesting vector Q, which connects the hole and electron Fermi surfaces. We point out that this difference comes from the coherence effect in the twoband superconductor. We suggest that the pairing symmetry could be clarified by observing the temperature dependence of both the density and spin structure factors at the nesting vector Q in neutron scattering measurements.

AB - From a theoretical point of view, we propose an experimental method to determine the pairing symmetry of iron pnictides. We focus on two kinds of pairing symmetries, s+- and s++, which are strong candidates for the pairing symmetry of iron pnictides. For each of these two symmetries, we calculate both the density and spin response functions by using the two-band BCS model within the one-loop approximation. As a result, a clear difference is found between the s+- and s++-wave states in the temperature dependence of the response functions at nesting vector Q, which connects the hole and electron Fermi surfaces. We point out that this difference comes from the coherence effect in the twoband superconductor. We suggest that the pairing symmetry could be clarified by observing the temperature dependence of both the density and spin structure factors at the nesting vector Q in neutron scattering measurements.

KW - Coherence effect

KW - Iron-pnictide superconductors

KW - Pairing symmetry

KW - Response functions

KW - Two-band BCS model

UR - http://www.scopus.com/inward/record.url?scp=77956248913&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77956248913&partnerID=8YFLogxK

U2 - 10.1143/JPSJ.79.074710

DO - 10.1143/JPSJ.79.074710

M3 - Article

AN - SCOPUS:77956248913

VL - 79

JO - Journal of the Physical Society of Japan

JF - Journal of the Physical Society of Japan

SN - 0031-9015

IS - 7

M1 - 074710

ER -