Jönsson, P. E., Mathieu, R., Wernsdorfer, W., Tkachuk, A. M., Barbara, B.
This recent paper by Ancona-Torres et al. (arXiv:0801.2181 [cond-mat]) does not bring more evidence of equilibrium quantum or classical phase transitions in the LiHo$_x$Y$_{1-x}$F$_4$ system than the...
Crystal-field level inversion in lightly Mn-doped Sr3Ru2O7 (2008)
Hossain, M. A., Hu, Z., Haverkort, M. W., Burnus, T., Chang, C. F., Klein, S., ...
Sr3(Ru1-xMnx)2O7, in which 4d-Ru is substituted by the more localized 3d-Mn, is studied by x-ray dichroism and spin-resolved density functional theory. We find that Mn impurities do not exhibit the...
The nanoscale phase separation in hole-doped manganites (2007)
A macroscopic phase separation, in which ferromagnetic clusters are observed in an insulating matrix, is sometimes observed, and believed to be essential to the colossal magnetoresistive (CMR)...
Chi, Songxue, Ye, F., Dai, Pengcheng, Fernandez-Baca, J. A., Huang, Q., Lynn, J. W., ...
We use neutron scattering to study the lattice and magnetic structure of the layered half-doped manganite Pr$_{0.5}$Ca$_{1.5}$MnO$_4$. On cooling from high temperature, the system first becomes...
Mathieu, R., He, J. P., Kaneko, Y., Yoshino, H., Asamitsu, A., Tokura, Y.
The ac-susceptibility of the electron doped single-layered manganite La$_{1.1}$Sr$_{0.9}$MnO$_4$ is analyzed in detail. A quasi two-dimensional (2$D$) antiferromagnetic (AFM) order with Ising...
Absence of Conventional Spin-Glass Transition in the Ising Dipolar System LiHo_xY_{1-x}F_4 (2007)
Jönsson, P. E., Mathieu, R., Wernsdorfer, W., Tkachuk, A. M., Barbara, B.
The magnetic properties of single crystals of LiHo_xY_{1-x}F_4 with x=16.5% and x=4.5% were recorded down to 35 mK using a micro-SQUID magnetometer. While this system is considered as the archetypal...
Yu, X. Z., Mathieu, R., Arima, T., Kaneko, Y., He, J. P., Uchida, M., ...
Structural features of the charge/orbital ordering (CO/OO) in single-layered manganites Pr1-xCa1+xMnO4 have been investigated systematically by transmission electron microscopy. Analyses of electron...
Mathieu, R., He, J. P., Yu, X. Z., Kaneko, Y., Uchida, M., Lee, Y. S., ...
The relationship between orbital and spin degrees of freedom in the single-crystals of the hole-doped Pr$_{1-x}$Ca$_{1+x}$MnO$_4$, 0.3 $\leq$ $x$ $\leq$ 0.7, has been investigated by means of...
Bandwidth-disorder phase diagram of half doped layered manganites (2006)
Mathieu, R., Uchida, M., Kaneko, Y., He, J. P., Yu, X. Z., Kumai, R., ...
Phase diagrams in the plane of $r_A$ (the average ionic radius, related to one-electron bandwidth $W$) and $\sigma^2$ (the ionic radius variance, measuring the quenched disorder), or...
Impurity-induced transition to a Mott insulator in Sr$_3$Ru$_2$O$_7$ (2005)
Mathieu, R., Asamitsu, A., Kaneko, Y., He, J. P., Yu, X. Z., Kumai, R., ...
The electrical, magnetic, and structural properties of Sr$_3$(Ru$_{1-x}$Mn$_x$)$_2$O$_7$ (0 $\leq x \leq$ 0.2) are investigated. The parent compound Sr$_3$Ru$_2$O$_7$ is a paramagnetic metal,...
Determination of the intrinsic anomalous Hall effect of SrRuO$_3$ (2005)
Mathieu, R., Jung, C. U., Yamada, H., Asamitsu, A., Kawasaki, M., Tokura, Y.
The anomalous Hall effect (AHE) of epitaxial SrRuO$_3$ films with varying lattice parameters is investigated, and analyzed according to the Berry-phase scenario. SrRuO$_3$ thin films were deposited...
Eu$_{0.5}$Sr$_{1.5}$MnO$_4$: a three-dimensional XY spin glass (2005)
Mathieu, R., Asamitsu, A., Kaneko, Y., He, J. P., Tokura, Y.
The frequency, temperature, and dc-bias dependence of the ac-susceptibility of a high quality single crystal of the Eu$_{0.5}$Sr$_{1.5}$MnO$_4$ layered manganite is investigated....
On the usefulness of very high resolution IKONOS satellite imagery for vegetation mapping (2004)
Mathieu, R, Aryal, J, Beck, K, Shanahan, D
Traditional vegetation mapping methodologies consist primarily of field surveying and mapping from aerial photographs or high resolution satellite images. Previous applications of satellite imagery...
Mathieu, R., Akahoshi, D., Asamitsu, A., Tomioka, Y., Tokura, Y.
The magnetic and electrical properties of high quality single crystals of $A$-site disordered (solid solution) Ln$_{0.5}$Ba$_{0.5}$MnO$_3$ are investigated near the phase boundary between the spin...
Photoemission studies of the annealing induced modifications of (Ga,Mn)As (2004)
Adell, M., Ilver, L., Kanski, J., Sadowski, J., Mathieu, R.
Using angle resolved photoemission we have investigated annealing-induced changes in Ga(1-x)Mn(x)As with x = 0.05. We find that the position of the Fermi energy is a function of annealing time and...
Scaling of the anomalous Hall effect in Sr$_{1-x}$Ca$_x$RuO$_3$ (2003)
Mathieu, R., Asamitsu, A., Yamada, H., Takahashi, K. S., Kawasaki, M., Fang, Z., ...
The anomalous Hall effect (AHE) of ferromagnetic thin films of Sr$_{1-x}$Ca$_{x}$RuO$_3$ (0 $\leq x \leq$ 0.4) is studied as a function of $x$ and temperature $T$. As $x$ increases, both the...
Anomalous Hall Effect and Magnetic Monopoles in Momentum-Space (2003)
Fang, Z., Nagaosa, N., Takahashi, K. S., Asamitsu, A., Mathieu, R., Ogasawara, T., ...
Efforts to find the magnetic monopole in real space have been made in cosmic rays and in accelerators, but up to now there is no firm evidence for its existence due to the very heavy mass $\sim...
Spin Glasses: A Ghost Story (2003)
Jönsson, P. E., Mathieu, R., Nordblad, P., Yoshino, H., Katori, H. Aruga, Ito, A.
Extensive experimental and numerical studies of the non-equilibrium dynamics of spin glasses subjected to temperature or bond perturbations have been performed to investigate chaos and memory effects...
Ferromagnetic GaMnAs/GaAs Superlattices - MBE Growth and Magnetic Properties (2003)
Sadowski, J., Mathieu, R., Svedlindh, P., Karlsteen, M., Kanski, J.
This paper presents the results of a study of the magnetic properties of Gallium Manganese Arsenide/Gallium Arsenide GaMnAs/GaAs) superlattices with magnetic GaMnAs layers of thickness between 8 and...
Sorensen, B., Sadowski, J., Mathieu, R., Svedlindh, P., Lindelof, P. E.
We report a clear correspondence between changes in the Curie temperature and carrier density upon annealing in epitaxially grown (Ga,Mn)As layers with thicknesses in the range between 5 nm and 20...
Strong rejuvenation in a chiral-glass superconductor (2002)
Gardchareon, A., Mathieu, R., Jönsson, P. E., Nordblad, P.
The glassy paramagnetic Meissner phase of a Bi$_2$Sr$_2$CaCu$_2$O$_x$ superconductor ($x$ = 8.18) is investigated by squid magnetometry, using ``dc-memory'' experiments employed earlier to study spin...
Magnetization of ultrathin (Ga,Mn)As layers (2002)
Mathieu, R., Sørensen, B. S., Sadowski, J., Södervall, U., Kanski, J., Svedlindh, P., ...
Kerr rotation and Superconducting QUantum Interference Device (SQUID) magnetometry measurements were performed on ultrathin (Ga$_{0.95}$Mn$_{0.05}$)As layers. The thinner layers (below 250 \AA)...
Fe/V and Fe/Co (001) superlattices: growth, anisotropy, magnetisation and magnetoresistance (2002)
Nordblad, P., Broddefalk, A., Mathieu, R., Blomqvist, P., Eriksson, O., Wäppling, R.
Some physical properties of bcc Fe/V and Fe/Co (001) superlattices are reviewed. The dependence of the magnetic anisotropy on the in-plane strain introduced by the lattice mismatch between Fe and V...
Magnetic Properties of Short Period InGaMnAs/InGaAs Superlattices (2002)
Sadowski, J., Mathieu, R., Svedlindh, P., Kanski, J., Karlsteen, M., Swiatek, K., ...
We have observed a paramagnetic-to-ferromagnetic phase transition in short period InGaMnAs/InGaAs superlattices. The thicknesses of magnetic InGaMnAs layers in the structures studied was chosen to be...
Ferromagnetism and interlayer exchange coupling in short period (Ga,Mn)As/GaAs superlattices (2002)
Mathieu, R., Svedlindh, P., Sadowski, J., Swiatek, K., Karlsteen, M., Kanski, J., ...
Magnetic properties of (Ga,Mn)As/GaAs superlattices are investigated. The structures contain magnetic (Ga,Mn)As layers, separated by thin layers of non-magnetic GaAs spacer. The short period...
Ferromagnetic GaMnAs/GaAs superlattices - MBE growth and magnetic properties (2002)
Sadowski, J., Mathieu, R., Svedlindh, P., Karlsteen, M., Kanski, J., Fu, Y., ...
We have studied the magnetic properties of (GaMnAs)(m)(GaAs)(n) superlattices with magnetic GaMnAs layers of thickness between eight and 16 molecular layers (ML) (23-45 Angstrom), and with...
Photoemission studies of Ga$_{1-x}$Mn$_{x}$As: Mn-concentration dependent properties (2001)
Asklund, H., Ilver, L., Kanski, J., Sadowski, J., Mathieu, R.
Using angle-resolved photoemission, we have investigated the development of the electronic structure and the Fermi level pinnning in Ga$_{1-x}$Mn$_{x}$As with Mn concentrations in the range 1--6%. We...
Ferromagnetic GaMnAs/GaAs superlattices - MBE growth and magnetic properties (2001)
Sadowski, J., Mathieu, R., Svedlindh, P., Karlsteen, M., Kanski, J., Fu, Y., ...
We have studied the magnetic properties of (GaMnAs)m/(GaAs)n superlattices with magnetic GaMnAs layers of thickness between 8 and 16 molecular layers (ML) (23-45 \AA), and with nonmagnetic GaAs...
Interlayer exchange coupling and giant magnetoresistance in Fe/V (001) superlattices (2001)
Broddefalk, A., Mathieu, R., Nordblad, P., Blomqvist, P., Wäppling, R., Lu, J., ...
Magnetization and magnetoresistivity studies of Fe/V (001) superlattices are reported. The first giant magnetoresistance peak with respect to the vanadium and iron layer thicknesses is investigated....
Magnetotransport in a bi-crystal film of La_0.7Sr_0.3MnO_3 (2001)
Mathieu, R., Svedlindh, P., Chakalov, R., Ivanov, Z. G.
Transport properties of an epitaxial film of La_0.7Sr_0.3MnO_3 (LSMO), deposited epitaxially on a LaAlO_3 bi-crystal substrate having a misorientation angle of 9.2 deg., have been studied. The film...
Mathieu, R., Nordblad, P., Raju, A. R., Rao, C. N. R.
The low temperature phase of single crystals of Nd$_{0.5}$Ca$_{0.5}$MnO$_3$ and Gd$_{0.5}$Ca$_{0.5}$MnO$_3$ manganites is investigated by squid magnetometry. Nd$_{0.5}$Ca$_{0.5}$MnO$_3$ undergoes a...
Memory and chaos in an Ising spin glass (2001)
Mathieu, R., Jönsson, P. E., Nordblad, P., Katori, H. Aruga, Ito, A.
The non-equilibrium dynamics of the model 3d-Ising spin glass - Fe$_{0.55}$Mn$_{0.45}$TiO$_3$ - has been investigated from the temperature and time dependence of the zero field cooled magnetization...
Sadowski, J., Mathieu, R., Svedlindh, P., Domagala, J. Z., Swiatek, K., ...
We have grown the ferromagnetic semiconductor GaMnAs containing up to 10% Mn by migration enhanced epitaxy at a substrate temperature of 150^oC. The alternate supply of As2 molecules and Ga and Mn...
Short range ferromagnetism and spin glass state in $\mathrm{Y_{0.7}Ca_{0.3}MnO_{3}}$ (2000)
Mathieu, R., Nordblad, P., Nam, D. N. H., Phuc, N. X., Khiem, N. V.
Dynamic magnetic properties of $\mathrm{Y_{0.7}Ca_{0.3}MnO_{3}}$ are reported. The system appears to attain local ferromagnetic order at $T_{\mathrm{SRF}} \approx 70$ K. Below this temperature the...
Mathieu, R., Svedlindh, P., Chakalov, R. A., Ivanov, Z. G.
The low field magnetotransport of La$_{0.7}$Sr$_{0.3}$MnO$_3$ (LSMO) films grown on SrTiO$_3$ substrates has been investigated. A high qualtity LSMO film exhibits anisotropic magnetoresistance (AMR)...
Mathieu, R., Svedlindh, P., Nordblad, P.
Magnetic, electric and structural properties of La$_{0.96-y}$Nd$_y$K$_{0.04}$MnO$_{3+\delta}$ with 0$\leq y \leq$0.4 have been studied experimentally. A disordered magnetic state is formed as La is...
Memory and superposition in a spin glass (2000)
Mathieu, R., Jönsson, P., Nam, D. N. H., Nordblad, P.
Non-equilibrium dynamics in a Ag(Mn) spin glass are investigated by measurements of the temperature dependence of the remanent magnetisation. Using specific cooling protocols before recording the...
Ostensen, M, Fuhrer, L, Mathieu, R, Seitz, M, Villiger, P
Objective: : To analyse the disease course of patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) during and after pregnancy by validated clinical instruments for measurement of...
Chi, Songxue, Ye, F., Dai, Pengcheng, Fernandez-Baca, J. A., Huang, Q., Lynn, J. W., ...
We use neutron scattering to study the lattice and magnetic structure of the layered half-doped manganite Pr0.5Ca1.5MnO4. On cooling from high temperature, the system first becomes charge-and...