Université de Fribourg

Mapping the unoccupied state dispersions in ${\mathrm{Ta}}_{2}{\mathrm{NiSe}}_{5}$ with resonant inelastic x-ray scattering

Monney, Claude ; Herzog, Marc ; Pulkkinen, Aki ; Huang, Y. ; Pelliciari, Jonathan ; Olalde-Velasco, P. ; Katayama, Naoyuk ; Nohara, Minoru ; Takagi, Hide ; Schmitt, Thorsten ; Mizokawa, Takashi

In: Physical Review B, 2020, vol. 102, no. 8, p. 085148

The transition metal chalcogenide Ta2NiSe5 undergoes a second-order phase transition at Tc=328K involving a small lattice distortion. Below Tc, a band gap at the center of its Brillouin zone increases up to about 0.35 eV. In this work, we study the electronic structure of Ta2NiSe5 in its low-temperature semiconducting phase, using resonant inelastic x-ray scattering (RIXS) at the Ni L3 edge....

Université de Fribourg

Coupled Cu and Mn charge and orbital orders in YBa₂Cu₃O₇/Nd 0.65 (Ca 1-y Sr y ) 0.35 MnO₃ multilayers

Perret, Edith ; Monney, Claude ; Johnston, S. ; Khmaladze, Jarji ; Lyzwa, Fryderyk ; Gaina, Roxana ; Dantz, M. ; Pelliciari, Jonathan ; Piamonteze, C. ; Mallett, B.P.P. ; Minola, M. ; Keimer, B. ; Schmitt, Thorsten ; Bernhard, Christian

In: Communications Physics, 2018, vol. 1, no. 1, p. 45

The observation of a charge density wave in the underdoped cuprate high Tc superconductors (Cu-CDW) raised a debate about its relationship with superconductivity. In bulk YBa2Cu3O7−δ the Cu-CDW is incipient and mainly pinned by defects. Nevertheless, a large magnetic field can induce a true long-range Cu- CDW order as it suppresses superconductivity. An enhanced Cu-CDW order was also ...

Université de Fribourg

Magnetic moment evolution and spin freezing in doped BaFe 2 As 2

Pelliciari, Jonathan ; Huang, Yaobo ; Ishii, Kenji ; Zhang, Chenglin ; Dai, Pengcheng ; Chen, Gen Fu ; Xing, Lingyi ; Wang, Xiancheng ; Jin, Changqing ; Ding, Hong ; Werner, Philipp ; Schmitt, Thorsten

In: Scientific Reports, 2017, vol. 7, no. 1, p. 8003

Fe-K β X-ray emission spectroscopy measurements reveal an asymmetric doping dependence of the magnetic moments μbare in electron- and hole-doped BaFe2As2. At low temperature, μbare is nearly constant in hole-doped samples, whereas it decreases upon electron doping. Increasing temperature substantially enhances μbare in the hole-doped region, which is naturally explained by the...