{"id":259,"date":"2016-08-05T19:22:35","date_gmt":"2016-08-05T19:22:35","guid":{"rendered":"http:\/\/girsh.rutgers.edu\/?p=259"},"modified":"2018-09-13T19:32:24","modified_gmt":"2018-09-13T19:32:24","slug":"bafe2as0-5p0-52","status":"publish","type":"post","link":"https:\/\/girsh.rutgers.edu\/index.php\/2016\/08\/05\/bafe2as0-5p0-52\/","title":{"rendered":"Collective excitations of dynamic Fermi surface deformations in BaFe2(As0.5P0.5)2"},"content":{"rendered":"

\"ForAuthors:<\/strong> S.-F. Wu, W.-L. Zhang, D. Hu, H.-H. Kung, A. Lee, H.-C. Mao, P.-C. Dai, H. Ding, P. Richard and G. Blumberg<\/p>\n

Abstract:<\/strong><\/p>\n

We use electronic Raman scattering to study the low-energy excitations in BaFe2<\/sub>(As0.5<\/sub>P0.5<\/sub>)2<\/sub> (Tc\u224816 K) samples. In addition to a superconducting pair breaking peak (2\u0394=6.7 meV) in the A1g<\/sub> channel with a linear tail towards zero energy, suggesting a nodal gap structure, we detect spectral features associated to Pomeranchuk oscillations in the A1g<\/sub>, B1g<\/sub> and B2g<\/sub> channels. We argue that the small Fermi energy of the system is an essential condition for these Pomeranchuk oscillations to be underdamped. The Pomeranchuk oscillations have the same frequencies in the B1g<\/sub> and B2g<\/sub> channels, which we explain by the mixing of these symmetries resulting from the removal of the \u03c3v<\/sub> and \u03c3d<\/sub> symmetry planes due to a large As\/P disorder. Interestingly, we show that the temperature at which the peaks corresponding to the Pomeranchuk oscillations get underdamped is consistent with the non-Fermi liquid to Fermi liquid crossover determined by transport, suggesting that the Pomeranchuk instability plays an important role in the low-energy physics of the Fe-based superconductors.<\/div>\n
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