Zaharko, O., Cervellino, A., Tsurkan, V., Christensen, N. B., Loidl, A.
Using neutron powder diffraction and Monte-Carlo simulations we show that a spin-liquid regime emerges at all compositions in the diamond-lattice antiferromagnets Co(Al1-xCox)2O4. This spin-liquid...
Freeman, P. G., Christensen, N. B., Prabhakaran, D., Boothroyd, A. T.
The temperature dependence of the magnetic order of stripe-ordered La(1.725)Sr(0.275)NiO(4) is investigated by neutron diffraction. Upon cooling, the widths if the magnetic Bragg peaks are observed...
Park, J. T., Inosov, D. S., Niedermayer, Ch., Sun, G. L., Haug, D., Christensen, N. B., ...
Here we present a combined study of the slightly underdoped novel pnictide superconductor Ba1-xKxFe₂As₂ by means of x-ray powder diffraction, neutron scattering, muon-spin rotation (µSR), and...
Park, J. T., Inosov, D. S., Niedermayer, Ch., Sun, G. L., Haug, D., Christensen, N. B., ...
Here we present a combined study of the slightly underdoped novel pnictide superconductor Ba1-xKxFe₂As₂ by means of x-ray powder diffraction, neutron scattering, muon-spin rotation (µSR), and...
Magnetic ordering in electronically phase separated Sr/O co-doped La(2-x)Sr(x)CuO(4+y) (2009)
Udby, L., Andersen, N. H., Chou, F. C., Christensen, N. B., Emery, S. B., Lefmann, K., ...
We present results of magnetic neutron diffraction experiments on the co-doped super-oxygenated La(2-x)Sr(x)CuO(4+y) (LSCO+O) system with x=0.09. The spin-density wave has been studied and we find...
Inosov, D. S., Leineweber, A., Yang, Xiaoping, Park, J. T., Christensen, N. B., Dinnebier, R., ...
We present x-ray powder diffraction (XRPD) and neutron diffraction measurements on the slightly underdoped iron pnictide superconductor Ba(1-x)K(x)Fe2As2, Tc = 32K. Below the magnetic transition...
Haug, D., Hinkov, V., Suchaneck, A., Inosov, D. S., Christensen, N. B., Niedermayer, Ch., ...
We present a neutron-scattering study of the static and dynamic spin correlations in the underdoped high-temperature superconductor YBa(2)Cu(3)O(6.45) in magnetic fields up to 15 T. The field...
Field-induced soft-mode quantum phase transition in La$_{1.855}$Sr$_{0.145}$CuO$_{4}$ (2009)
Chang, J., Christensen, N. B., Niedermayer, Ch., Lefmann, K., Roennow, H. M., McMorrow, D. F., ...
Inelastic neutron-scattering experiments on the high-temperature superconductor La$_{1.855}$Sr$_{0.145}$CuO$_{4}$ reveal a magnetic excitation gap $\Delta$ that decreases continuously upon...
Field-induced magnetic phases and electric polarization in LiNiPO4 (2009)
Jensen, T. B. S., Christensen, N. B., Kenzelmann, M., Rønnow, H. M., Niedermayer, C., Andersen, N. H., ...
Neutron diffraction is used to probe the (H,T) phase diagram of magneto-electric (ME) LiNiPO4 for magnetic fields along the c-axis. At zero field the Ni spins order in two antiferromagnetic phases....
Field-controlled magnetic order in the quantum spin-ladder system (Hpip)2CuBr4 (2009)
Thielemann, Beni, Rüegg, Christian, Kiefer, Klaus, Rønnow, Henrik M., Normand, Bruce, Bouillot, P, ...
Field-induced magnetic phases and electric polarization in LiNiPO4 (2009)
N.B. Christensen, M. Kenzelmann, H.M. Rønnow, C. Niedermayer, ...
Journal article
Park, J. T., Inosov, D. S., Niedermayer, Ch., Sun, G. L., Haug, D., Christensen, N. B., ...
Here we present a combined study of the slightly underdoped novel pnictide superconductor Ba(1-x)K(x)Fe(2)As(2) by means of X-ray powder diffraction, neutron scattering, muon spin rotation (muSR),...
Field-Controlled Magnetic Order in the Quantum Spin-Ladder System (Hpip)2CuBr4 (2008)
Thielemann, B., Rüegg, Ch., Kiefer, K., Rønnow, H. M., Normand, B., Bouillot, P., ...
Neutron diffraction is used to investigate the field-induced, antiferromagnetically ordered state in the two-leg spin-ladder material (Hpip)2CuBr4. This "classical" phase, a consequence of weak...
Chang, J., Niedermayer, Ch., Gilardi, R., Christensen, N. B., Ronnow, H. M., McMorrow, D. F., ...
We report the results of a combined muon-spin rotation and neutron-scattering study on La2-xSrxCuO4 in the vicinity of the so-called 1/8 anomaly. Application of a magnetic field drives the system...
Chang, J., Niedermayer, Ch., Gilardi, R., Christensen, N. B., Ronnow, H. M., McMorrow, D. F., ...
We report the results of a combined muon spin rotation and neutron scattering study on La2-xSrxCuO4 in the vicinity of the so-called 1/8-anomaly. Application of a magnetic field drives the system...
Quantum dynamics and entanglement of spins on a square lattice (2007)
Christensen, N. B., Ronnow, H. M., McMorrow, D. F., Harrison, A., Perring, T. G., Enderle, M., ...
Bulk magnetism in solids is fundamentally quantum mechanical in nature. Yet in many situations, including our everyday encounters with magnetic materials, quantum effects are masked, and it often...
Chang, J., Schnyder, A. P., Gilardi, R., Ronnow, H. M., Pailhes, S., Christensen, N. B., ...
High-resolution neutron inelastic scattering experiments in applied magnetic fields have been performed on La$_{1.895}$Sr$_{0.105}$CuO$_{4}$ (LSCO). In zero field, the temperature dependence of the...
Quantum dynamics and entanglement of spins on a square lattice (2007)
Christensen, N. B., Ronnow, H. M., McMorrow, D. F., Harrison, A., Perring, T. G., Enderle, M., ...
Bulk magnetism in solids is fundamentally quantum mechanical in nature. Yet in many situations, including our everyday encounters with magnetic materials, quantum effects are masked, and it often...
Nature of the magnetic order in the charge-ordered cuprate La1.48Nd0.4Sr0.12CuO4 (2007)
Christensen, N. B., Ronnow, H. M., Mesot, J., Ewings, R. A., Momono, N., Oda, M., ...
Using polarized neutron scattering we establish that the magnetic order in La1.48Nd0.4Sr0.12CuO4 is either (i) one dimensionally modulated and collinear, consistent with the stripe model or (ii) two...
Chang, J., Schnyder, A. P., Gilardi, R., Ronnow, H. M., Pailhes, S., Christensen, N. B., ...
High-resolution neutron inelastic scattering experiments in applied magnetic fields have been performed on La1.895Sr0.105CuO4 (LSCO). In zero field, the temperature dependence of the low-energy peak...
Christensen, N. B., Ronnow, H. M., Mesot, J., Ewings, R. A., Momono, N., Oda, M., ...
Using polarized neutron scattering we establish that the magnetic order in La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_4$ is either (i) one dimensionally modulated and collinear, consistent with the stripe...
Three-dimensionality of field-induced magnetism in a high-temperature superconductor (2006)
Lake, B., Lefmann, K., Christensen, N. B., Aeppli, G., McMorrow, D. F., Ronnow, H. M., ...
Many physical properties of high-temperature (high-Tc) superconductors are two-dimensional phenomena derived from their square planar CuO2 building blocks. This is especially true of the magnetism...
M. Cardenas E., W. C. Lindemann, N. B. Christensen, E. Salazar Sosa
Nitrogen mineralization and distribution through the root zone in two tillage systems under field conditions
Bahl, C. R. H., Lefmann, K., Abrahamsen, A. B., Ronnow, H. M., Saxild, F., Jensen, T. B. S., ...
Recently a monochromatic multiple data taking mode has been demonstrated for diffraction experiments using a RITA type cold neutron spectrometer with a multi-bladed analyser and a position-sensitive...
Three dimensionality of field-induced magnetism in a high-temperature superconductor (2005)
Lake, B, Lefmann, K, Christensen, NB, Aeppli, G, McMorrow, DF, Voderwisch, P, ...
Three-dimensionality of field-induced magnetism in a high-temperature superconductor (2005)
Lake, B., Lefmann, K., Christensen, N. B., Aeppli, G., McMorrow, D. F., Ronnow, H. M., ...
Many physical properties of high-temperature superconductors are two-dimensional phenomena derived from their square-planar CuO2 building blocks. This is especially true of the magnetism from the...
Dispersive Excitations in the High-Temperature Superconductor La2-xSrxCuO4 (2004)
Christensen, N.B., McMorrow, D.F., Ronnow, H.M., Lake, B., Hayden, S.M., Aeppli, G., ...
High-resolution neutron scattering experiments on optimally doped La2-xSrxCuO4 (x=0.16) reveal that the magnetic excitations are dispersive. The dispersion is the same as in YBa2Cu3O6.85, and is...
Universal Dispersive Excitations in the High-Temperature Superconductors (2004)
Christensen, N. B., McMorrow, D. F., Ronnow, H. M., Lake, B., Hayden, S. M., Aeppli, G., ...
High-resolution neutron scattering experiments on optimally doped La$_{2-x}$Sr$_x$CuO$_4$ have been performed which reveal that the magnetic excitations are dispersive. The dispersion is found to be...
Dispersive excitations in the high-temperature superconductor La2-xSrxCuO4 (2004)
Christensen, N B, McMorrow, D F, Ronnow, H M, Lake, B, Hayden, S M, Aeppli, G, ...
Deviations from linear spin wave theory in the 2D, S=1/2 Heisenberg antiferromagnet CFTD (2004)
Christensen, N B, McMorrow, D F, Ronnow, H M, Harrison, A, Perring, T G, Coldea, R
Static and dynamic spins in superconducting La2-xSrxCuO4: The Riso years (2004)
Lefmann, K, Lake, B, Aeppli, G, Cheong, S W, Christensen, N B, Clausen, K N, ...
Effects of magnetic field on the cuprate high-T-c superconductor La2-xSrxCuO4 (2004)
Lake, B, Aeppli, G, Christensen, N B, Lefmann, K, McMorrow, D F, Clausen, K N, ...
Static and dynamic spins in superconducting La2-xSrxCuO4: The Riso years (2004)
Lefmann, K., Lake, B., Aeppli, G., Cheong, S. W., Christensen, N. B., Clausen, K. N., ...
One important area of modern condensed matter research is the investigation of the nature of the superconducting cuprates. Much progress in this field has been obtained with the technique of neutron...
Effects of magnetic field on the cuprate high-T-c superconductor La2-xSrxCuO4 (2004)
Lake, B., Aeppli, G., Christensen, N. B., Lefmann, K., McMorrow, D. F., Clausen, K. N., ...
This article discusses neutron scattering measurements on the cuprate, high transition temperature superconductor La2-xSrxCuO4 (LSCO) in an applied magnetic field. LSCO is a type-II superconductor...
Dispersive excitations in the high-temperature superconductor La2-xSrxCuO4 (2004)
Christensen, N. B., McMorrow, D. F., Ronnow, H. M., Lake, B., Hayden, S. M., Aeppli, G., ...
High-resolution neutron scattering experiments on optimally doped La2-xSrxCuO4 (x=0.16) reveal that the magnetic excitations are dispersive. The dispersion is the same as in YBa2Cu3O6.85, and is...
Deviations from linear spin wave theory in the 2D, S=1/2 Heisenberg antiferromagnet CFTD (2004)
Christensen, N. B., McMorrow, D. F., Ronnow, H. M., Harrison, A., Perring, T. G., Coldea, R.
The spin excitation spectrum in the 2D square lattice Heisenberg antiferromagnet CFTD has been investigated using time-of-flight neutron scattering. The magnon dispersion and intensities have been...
Lake, B., Rønnow, H.M., Christensen, N.B., Aeppli, G., Lefmann, K., McMorrow, D.F., ...
One view of the high-transition-temperature (high-Tc) copper oxide superconductors is that they are conventional superconductors where the pairing occurs between weakly interacting quasiparticles...
Lake, B., Ronnow, H. M., Christensen, N. B., Aeppli, G., Lefmann, K., McMorrow, D. F., ...
One view of the high-transition-temperature (high-T-c) copper oxide superconductors is that they are conventional superconductors where the pairing occurs between weakly interacting quasi-particles...
Field-induced antiferromagnetism in the high-temperature superconductor La2-xSrxCuO4 (2002)
Lake, B., Mason, T. E., Aeppli, G., Lefmann, K., Christensen, N. B., McMorrow, D. F., ...
Vortex magnetism in the high-temperatures superconductor La2-xSrxCuO4 (2002)
Lake, B., Mason, T. E., Aeppli, G., Lefmann, K., Christensen, N. B., McMorrow, D. F., ...
Antiferromagnetic vortex state in a high-temperature superconductor (2001)
Lake, B., Ronnow, H. M., Christensen, N. B., Aeppli, G., Lefmann, K., McMorrow, D. F., ...
There is strong evidence that magnetic interactions play a crucial role in the mechanism driving high-temperature superconductivity in cuprate superconductors. To investigate this further we have...
Quantum dynamics and entanglement of spins on a square lattice
Christensen, N. B., Rønnow, H. M., McMorrow, D. F., Harrison, A., Perring, T. G., Enderle, M., ...
Bulk magnetism in solids is fundamentally quantum mechanical in nature. Yet in many situations, including our everyday encounters with magnetic materials, quantum effects are masked, and it often...