Symmetry 2012, 4(1), 251-264; doi:10.3390/sym4010251
Article

One-Sign Order Parameter in Iron Based Superconductor

Sergey V. Borisenko 1,* email, Volodymyr B. Zabolotnyy 1 email, Alexnader A. Kordyuk 1,2 email, Danil V. Evtushinsky 1 email, Timur K. Kim 1,3 email, Igor V. Morozov 4 email, Rolf Follath 5 email and Bernd Büchner 1 email
1 Leibniz-Institute for Solid State Research, IFW-Dresden, D-01171 Dresden, Germany 2 Institute for Metal Physics, 03142 Kyiv, Ukraine 3 Diamond Light Source Ltd., Didcot, Oxfordshire, OX11 0DE, UK 4 Moscow State University, 119991 Moscow, Russia 5 Helmholtz-Zentrum Berlin, BESSY, D-12489 Berlin, Germany
* Author to whom correspondence should be addressed.
Received: 2 March 2012; in revised form: 14 March 2012 / Accepted: 16 March 2012 / Published: 21 March 2012
(This article belongs to the Special Issue Symmetries of Electronic Order)
PDF Full-text Download PDF Full-Text [2311 KB, uploaded 21 March 2012 12:29 CET]
Abstract: The onset of superconductivity at the transition temperature is marked by the onset of order, which is characterized by an energy gap. Most models of the iron-based superconductors find a sign-changing (s±) order parameter [1–6], with the physical implication that pairing is driven by spin fluctuations. Recent work, however, has indicated that LiFeAs has a simple isotropic order parameter [7–9] and spin fluctuations are not necessary [7,10], contrary to the models [1–6]. The strength of the spin fluctuations has been controversial [11,12], meaning that the mechanism of superconductivity cannot as yet be determined. We report the momentum dependence of the superconducting energy gap, where we find an anisotropy that rules out coupling through spin fluctuations and the sign change. The results instead suggest that orbital fluctuations assisted by phonons [13,14] are the best explanation for superconductivity.
Keywords: iron-based superconductors; ARPES; LiFeAs; order parameter

Article Statistics

Click here to load and display the download statistics.

Cite This Article

MDPI and ACS Style

Borisenko, S.V.; Zabolotnyy, V.B.; Kordyuk, A.A.; Evtushinsky, D.V.; Kim, T.K.; Morozov, I.V.; Follath, R.; Büchner, B. One-Sign Order Parameter in Iron Based Superconductor. Symmetry 2012, 4, 251-264.

AMA Style

Borisenko SV, Zabolotnyy VB, Kordyuk AA, Evtushinsky DV, Kim TK, Morozov IV, Follath R, Büchner B. One-Sign Order Parameter in Iron Based Superconductor. Symmetry. 2012; 4(1):251-264.

Chicago/Turabian Style

Borisenko, Sergey V.; Zabolotnyy, Volodymyr B.; Kordyuk, Alexnader A.; Evtushinsky, Danil V.; Kim, Timur K.; Morozov, Igor V.; Follath, Rolf; Büchner, Bernd. 2012. "One-Sign Order Parameter in Iron Based Superconductor." Symmetry 4, no. 1: 251-264.

Symmetry EISSN 2073-8994 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert