Université de Fribourg

Revealing ‘plasmaron’ feature in DySb by optical spectroscopy study

Ban, W J ; Wu, D S ; Xu, Bing ; Luo, J L ; Xiao, Hong

In: Journal of Physics: Condensed Matter, 2019, vol. 31, no. 40, p. 405701

We report magnetic susceptibility, resistivity and optical spectroscopy study on single crystal sample DySb. It exhibits extremely large magnetoresistance (XMR), and a magnetic phase transition from paramagnetic (PM) to antiferromagnetic (AFM) state at about 10 K. A 'screened' plasma edge at about 4000 cm−1 is revealed by optical measurement, which suggests that the material has a low...

Université de Fribourg

Scaling of the Fano effect of the in-plane Fe-As phonon and the superconducting critical temperature in ${\mathrm{Ba}}_{1\ensuremath{-}x}{\mathrm{K}}_{x}{\mathrm{Fe}}_{2}{\mathrm{As}}_{2}$

Xu, Bing ; Cappelluti, E. ; Benfatto, Larra ; Mallett, Benjamin P. P. ; Marsik, Premysl ; Sheveleva, Evgeniia ; Lyzwa, F. ; Wolf, Thomas ; Yang, Rui ; Qiu, X. G. ; Dai, Y. M. ; Wen, H. H. ; Lobo, R. P. S. M. ; Bernhard, Christian

In: Physical Review Letters, 2019, vol. 122, no. 21, p. 217002

By means of infrared spectroscopy, we determine the temperature-doping phase diagram of the Fano effect for the in-plane Fe-As stretching mode in Ba1−xKxFe2As2. The Fano parameter 1=q2, which is a measure of the phonon coupling to the electronic particle-hole continuum, shows a remarkable sensitivity to the magnetic and structural orderings at low temperatures. Most strikingly, at elevated...

Université de Fribourg

Revealing the pseudogap in ${\mathrm{Sr}}_{3}{({\mathrm{Ru}}_{0.985}{\mathrm{Fe}}_{0.015})}_{2}{\mathrm{O}}_{7}$ by optical spectroscopy

Ban, W. J. ; Xu, Bing ; Li, W. H. ; Wang, Y. ; Ge, J. J. ; Li, P. G. ; Yang, R. ; Dai, Y. M. ; Mao, Z. Q. ; Xiao, H.

In: Physical Review B, 2018, vol. 98, no. 20, p. 205111

We report resistivity, magnetization, and optical spectroscopy study on single-crystal sample of Sr3(Ru0.985Fe0.015 )2O7. An upturn is observed in resistivity at about 30 K. Below 30 K, the dip in resistivity R(ω), the suppression in scattering rate 1/τ (ω), the peaklike feature in optical conductivity σ1(ω), and the remainder of spectral weight all suggest the formation of a pseudogap....