@article{RettigDornesThielemannKuehnetal.2016,
  author    = {Rettig, L. and Dornes, C. and Thielemann-Kuehn, Nele and Pontius, N. and Zabel, Hartmut and Schlagel, D. L. and Lograsso, T. A. and Chollet, M. and Robert, A. and Sikorski, M. and Song, S. and Glownia, J. M. and Schuessler-Langeheine, Christian and Johnson, S. L. and Staub, U.},
  title     = {Itinerant and Localized Magnetization Dynamics in Antiferromagnetic Ho},
  series = {Physical review letters},
  volume    = {116},
  journal   = {Physical review letters},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {0031-9007},
  doi       = {10.1103/PhysRevLett.116.257202},
  pages     = {6382 -- 6389},
  year      = {2016},
  abstract  = {Using femtosecond time-resolved resonant magnetic x-ray diffraction at the Ho L-3 absorption edge, we investigate the demagnetization dynamics in antiferromagnetically ordered metallic Ho after femtosecond optical excitation. Tuning the x-ray energy to the electric dipole (E1, 2p -> 5d) or quadrupole (E2, 2p -> 4f) transition allows us to selectively and independently study the spin dynamics of the itinerant 5d and localized 4f electronic subsystems via the suppression of the magnetic (2 1 3-tau) satellite peak. We find demagnetization time scales very similar to ferromagnetic 4f systems, suggesting that the loss of magnetic order occurs via a similar spin-flip process in both cases. The simultaneous demagnetization of both subsystems demonstrates strong intra-atomic 4f-5d exchange coupling. In addition, an ultrafast lattice contraction due to the release of magneto-striction leads to a transient shift of the magnetic satellite peak.},
  language  = {en}
}
@article{SiebrechtSchreyerEnglischetal.1997,
  author    = {Siebrecht, R. and Schreyer, A. and Englisch, Uwe and Pietsch, Ullrich and Zabel, Hartmut},
  title     = {The new reflectometer ADAM at the ILL},
  year      = {1997},
  language  = {en}
}
@article{ThielemannKuehnSchickPontiusetal.2017,
  author    = {Thielemann-K{\"u}hn, Nele and Schick, Daniel and Pontius, Niko and Trabant, Christoph and Mitzner, Rolf and Holldack, Karsten and Zabel, Hartmut and F{\"o}hlisch, Alexander and Schuessler-Langeheine, Christian},
  title     = {Ultrafast and Energy-Efficient Quenching of Spin Order: Antiferromagnetism Beats Ferromagnetism},
  series = {Physical review letters},
  volume    = {119},
  journal   = {Physical review letters},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {0031-9007},
  doi       = {10.1103/PhysRevLett.119.197202},
  pages     = {6},
  year      = {2017},
  abstract  = {By comparing femtosecond laser pulse induced ferro- and antiferromagnetic dynamics in one and the same material-metallic dysprosium-we show both to behave fundamentally different. Antiferromagnetic order is considerably faster and much more efficiently reduced by optical excitation than its ferromagnetic counterpart. We assign the fast and extremely efficient process in the antiferromagnet to an interatomic transfer of angular momentum within the spin system. Our findings imply that this angular momentum transfer channel is effective in other magnetic metals with nonparallel spin alignment. They also point out a possible route towards energy-efficient spin manipulation for magnetic devices.},
  language  = {en}
}
@article{PudellvonReppertSchicketal.2019,
  author    = {Pudell, Jan-Etienne and von Reppert, Alexander and Schick, D. and Zamponi, F. and R{\"o}ssle, Matthias and Herzog, Marc and Zabel, Hartmut and Bargheer, Matias},
  title     = {Ultrafast negative thermal expansion driven by spin disorder},
  series = {Physical review : B, Condensed matter and materials physics},
  volume    = {99},
  journal   = {Physical review : B, Condensed matter and materials physics},
  number    = {9},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {2469-9950},
  doi       = {10.1103/PhysRevB.99.094304},
  pages     = {7},
  year      = {2019},
  abstract  = {We measure the transient strain profile in a nanoscale multilayer system composed of yttrium, holmium, and niobium after laser excitation using ultrafast x-ray diffraction. The strain propagation through each layer is determined by transient changes in the material-specific Bragg angles. We experimentally derive the exponentially decreasing stress profile driving the strain wave and show that it closely matches the optical penetration depth. Below the Neel temperature of Ho, the optical excitation triggers negative thermal expansion, which is induced by a quasi-instantaneous contractive stress and a second contractive stress contribution increasing on a 12-ps timescale. These two timescales were recently measured for the spin disordering in Ho [Rettig et al., Phys. Rev. Lett. 116, 257202 (2016)]. As a consequence, we observe an unconventional bipolar strain pulse with an inverted sign traveling through the heterostructure.},
  language  = {en}
}