Zobrazeno 1 - 10
of 529
pro vyhledávání: '"Lefmann, K"'
Autor:
Holm-Dahlin, S., Larsen, J., Jacobsen, H., Rømer, A. T., Ţuţueanu, A. -E., Ahmad, M., Grivel, J. -C., Scheuermann, R., Zimmermann, M. v., Boehm, M., Steffens, P., Niedermayer, Ch., Pedersen, K. S., Christensen, N. B., Wells, B. O., Lefmann, K., Udby, L.
We present a combined neutron diffraction and high field muon spin rotation ($\mu$SR) study of the magnetically ordered and superconducting phases of the high-temperature superconductor La$_{1.94}$Sr$_{0.06}$CuO$_{4+y}$ ($T_{\rm c} = 37.5(2)$~K) in a
Externí odkaz:
http://arxiv.org/abs/2101.10672
Autor:
Willendrup, P. K., Lefmann, K.
Publikováno v:
Journal of Neutron Research 22, 1-16 (2020)
We present an overview of, and an introduction to, the general-purpose neutron simulation package McStas. We present the basic principles behind Monte Carlo ray-tracing simulations of neutrons performed in the package and present a few simple example
Externí odkaz:
http://arxiv.org/abs/2010.00318
Autor:
Willendrup, P. K., Lefmann, K.
An key element of the success of McStas is the component layer where users and developers alike are contributing to the description of new physical models and features. In McStas, components realise all physical elements of the simulated instrument f
Externí odkaz:
http://arxiv.org/abs/2010.00278
Autor:
Ţuţueanu, A. -E., Tejsner, T. B., Lǎcǎtuşu, M. E., Hansen, H. W., Eliasen, K. L., Boehm, M., Steffens, P., Niedermayer, C., Lefmann, K.
Publikováno v:
Journal of Neutron Research, vol. 22, no. 1, pp. 49-56, 2020
Neutron diffraction has been a very prominent tool to investigate high-temperature superconductors, in particular through the discovery of an incommensurate magnetic signal known as stripes. We here report the findings of a neutron diffraction experi
Externí odkaz:
http://arxiv.org/abs/2006.02999
Autor:
Tutueanu, A. -E., Sales, M., Eliasen, K. L., Lacatusu, M. -E., Grivel, J. -C., Kardjilov, N., Manke, I., Krzyzagorski, M., Sassa, Y., Andersson, M. S., Schmidt, S., Lefmann, K.
Proper characterisation of investigated samples is vital when studying superconductivity as impurities and doping inhomogeneities can affect the physical properties of the measured system. We present a method where a polarised neutron imaging setup u
Externí odkaz:
http://arxiv.org/abs/2006.01776
Autor:
Nocerino, E., Stuhr, U., San Lorenzo, I., Mazza, F., Mazzone, D.G., Hellsvik, J., Hasegawa, S., Asai, S., Masuda, T., Itoh, S., Minelli, A., Hossain, Z., Thamizhavel, A., Lefmann, K., Sassa, Y., Månsson, M.
Publikováno v:
In Journal of Science: Advanced Materials and Devices December 2023 8(4)
Autor:
Lass, J., Andersen, Ch. Røhl, Leerberg, H. K., Birkemose, S., Toth, S., Stuhr, U., Bartkowiak, M., Niedermayer, Ch., Lu, Zhilun, Toft-Petersen, R., Retuerto, M., Birk, J. Okkels, Lefmann, K.
Publikováno v:
Phys. Rev. B 101, 054415 (2020)
Using single crystal neutron scattering we show that the magnetic structure Ni$_3$TeO$_6$ at fields above 8.6 T along the $c$ axis changes from a commensurate collinear antiferromagnetic structure with spins along c and ordering vector $Q_C$= (0 0 1.
Externí odkaz:
http://arxiv.org/abs/1909.13734
Autor:
Larsen, C. B., Rømer, A. T., Janas, S., Treue, F., Mønsted, B., Shaik, N. E., Rønnow, H. M., Lefmann, K.
Publikováno v:
Phys. Rev. B 99, 054432 (2019)
We have used exact numerical diagonalization to study the excitation spectrum and the dynamic spin correlations in the $s=1/2$ next-next-nearest neighbor Heisenberg antiferromagnet on the square lattice, with additional 4-spin ring exchange from high
Externí odkaz:
http://arxiv.org/abs/1812.04277
Autor:
Ray, P. J., Andersen, N. H., Jensen, T. B. S., Mohottala, H. E., Niedermayer, Ch., Lefmann, K., Wells, B. O., Zimmermann, M. v., Udby, L.
Publikováno v:
Phys. Rev. B 96, 174106 (2017)
We present high energy X-ray diffraction studies on the structural phases of an optimal high-$T_c$ superconductor La$_{2-x}$Sr$_x$CuO$_{4+y}$ tailored by co-hole-doping. This is specifically done by varying the content of two very different chemical
Externí odkaz:
http://arxiv.org/abs/1707.08871
Autor:
Holm, S. L., Kreisel, A., Schäffer, T. K., Bakke, A., Bertelsen, M., Hansen, U. B., Retuerto, M., Larsen, J., Prabhakaran, D., Deen, P. P., Yamani, Z., Birk, J. O., Stuhr, U., Niedermayer, Ch., Fennell, A. L., Andersen, B. M., Lefmann, K.
Publikováno v:
Phys. Rev. B 97, 134304 (2018)
Inelastic neutron scattering has been used to study the magneto-elastic excitations in the multiferroic manganite hexagonal YMnO$_3$. An avoided crossing is found between magnon and phonon modes close to the Brillouin zone boundary in the $(a,b)$-pla
Externí odkaz:
http://arxiv.org/abs/1707.02468