Scanning tunneling microscopy of the 32 K superconductor (Sr1-xKx)Fe2As2
arXiv:0806.4400
Abstract
The discovery of high temperature superconductivity in La[O1-xFx]FeAs at the beginning of this year [1] has generated much excitement and has led to the rapid discovery of similar compounds with as high as 55 K transition temperatures [2]. The high superconducting transition temperatures are seemingly incompatible with the electron-phonon driven pairing of conventional superconductors, resulting in wide speculation as to the mechanism and nature of the superconductivity in these materials. Here we report results of the first scanning tunneling microscopy study of the 32 K superconductor (Sr1-xKx)Fe2As2. We find two distinct topographic regions on the sample, one with no apparent atomic corrugation, and another marked by a stripe-like modulation at double the atomic periodicity. In the latter the stripes appear to modulate the local density of states, occasionally revealing a Delta = 10 mV gap with a shape consistent with unconventional (non-s wave) superconductivity.
5 pages, 4 figures Minor changes: fixed unit cell size, added references
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Cited by in corpus (6)
- Observation of the Josephson effect in Pb/(Ba,K)Fe2As2 single crystal junctions
- Investigation of Superconducting Gap Structure in TbFeAsOF using Point Contact Andreev Reflection
- Evidence of a universal and isotropic 2Δ/kBTC ratio in 122-type iron pnictide superconductors over a wide doping range
- Experimental determination of the microscopic origin of magnetism in parent iron pnictides
- Impurity effect as a probe for order parameter symmetry in iron-based superconductors
- Iron based superconductors: A brief overview