TY - JOUR
T1 - Microwave surface impedance measurements of LiFeAs, LiFe(As,P) and FeSe1-xTex single crystals
AU - Imai, Y.
AU - Takahashi, H.
AU - Okada, T.
AU - Yoshinaka, T.
AU - Komiya, S.
AU - Kitagawa, K.
AU - Matsubayashi, K.
AU - Tsukada, I.
AU - Uwatoko, Y.
AU - Maeda, A.
PY - 2011/11
Y1 - 2011/11
N2 - We study microwave surface impedance measurements of LiFeAs, LiFe(As,P) and FeSe1-xTex single crystals. The in-plane penetration depths of LiFeAs and LiFe(As,P) depend on temperature exponentially at low temperatures, which is a strong indication that these two materials have the nodeless superconducting gap. The temperature dependence of the superfluid density indicates that LiFeAs and LiFe(As,P) are multi-gap superconductors with at least two isotropic gaps. In FeSe1-xTex, on the other hand, the quadratic temperature dependence of the in-plane penetration depth appears, which indicates the existence of some sort of quasiparticle excitations. In addtion, the real part of the microwave conductivity exhibits a large enhancement below Tc in all three materials, which results from the increase of the quasiparticle relaxation time, τ, below Tc.
AB - We study microwave surface impedance measurements of LiFeAs, LiFe(As,P) and FeSe1-xTex single crystals. The in-plane penetration depths of LiFeAs and LiFe(As,P) depend on temperature exponentially at low temperatures, which is a strong indication that these two materials have the nodeless superconducting gap. The temperature dependence of the superfluid density indicates that LiFeAs and LiFe(As,P) are multi-gap superconductors with at least two isotropic gaps. In FeSe1-xTex, on the other hand, the quadratic temperature dependence of the in-plane penetration depth appears, which indicates the existence of some sort of quasiparticle excitations. In addtion, the real part of the microwave conductivity exhibits a large enhancement below Tc in all three materials, which results from the increase of the quasiparticle relaxation time, τ, below Tc.
KW - FeSe Te
KW - LiFeAs
KW - Microwave surface impedance
KW - Penetration depth
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U2 - 10.1016/j.physc.2011.05.013
DO - 10.1016/j.physc.2011.05.013
M3 - Article
AN - SCOPUS:80055019658
SN - 0921-4534
VL - 471
SP - 630
EP - 633
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
IS - 21-22
ER -