Université de Fribourg

Dimensionality control of electronic phase transitions in nickel-Oxide superlattices

Boris, A. V. ; Matiks, Y. ; Benckiser, E. ; Frano, A. ; Popovich, P. ; Hinkov, V. ; Wochner, P. ; Castro-Colin, M. ; Detemple, E. ; Malik, Vivek Kumar ; Bernhard, Christian ; Prokscha, T. ; Suter, A. ; Salman, Z. ; Morenzoni, E. ; Cristiani, G. ; Habermeier, H.-U. ; Keimer, B.

In: Science, 2011, vol. 332, no. 6032, p. 937-940

The competition between collective quantum phases in materials with strongly correlated electrons depends sensitively on the dimensionality of the electron system, which is difficult to control by standard solid-state chemistry. We have fabricated superlattices of the paramagnetic metal lanthanum nickelate (LaNiO₃) and the wide-gap insulator lanthanum aluminate (LaAlO₃) with atomically...

Université de Fribourg

Engineering spin propagation across a hybrid organic/inorganic interface using a polar layer

Schulz, Leander ; Nuccio, L. ; Willis, M. ; Desai, P. ; Shakya, P. ; Kreouzis, T. ; Malik, Vivek Kumar ; Bernhard, Christian ; Pratt, F. L. ; Morley, N. A. ; Suter, A. ; Nieuwenhuys, G. J. ; Prokscha, T. ; Morenzoni, E. ; Gillin, W. P. ; Drew, Alan J.

In: Nature Materials, 2011, vol. 10, p. 39–44

Spintronics has shown a remarkable and rapid development, for example from the initial discovery of giant magnetoresistance in spin valves (Baibich, M. N. et al. Giant magnetoresistance of (001)Fe/(001)Cr magnetic superlattices. Phys. Rev. Lett. 61, 2472–2475, 1988) to their ubiquity in hard-disk read heads in a relatively short time. However, the ability to fully harness electron spin as...

Université de Fribourg

Muon spin rotation study of magnetism and superconductivity in BaFe2−xCoxAs₂ and Pr1−xSrxFeAsO

Bernhard, Christian ; Drew, Alan J. ; Schulz, Leander ; Malik, Vivek Kumar ; Rössle, Matthias ; Niedermayer, Ch. ; Wolf, Th. ; Varma, G. D. ; Mu, G. ; Wen, H.-H. ; Liu, H. ; Wu, G. ; Chen, X. H.

In: New Journal of Physics, 2009, vol. 11, p. 055050

We present a muon spin rotation (μSR) study of the magnetic and superconducting properties of single crystals of electron-doped BaFe2−xCoxAs₂ with x = 0.08, 0.20 and 0.25 (Tc = 9, 25 and 20 K) and of polycrystalline hole-doped Pr1−xSrxFeAsO with x = 0 and 0.2 (Tc = 15...

Université de Fribourg

Direct measurement of the electronic spin diffusion length in a fully functional organic spin valve by low-energy muon spin rotation

Drew, Alan J. ; Hoppler, Julian ; Schulz, Leander ; Pratt, F. L. ; Desai, P. ; Shakya, P. ; Kreouzis, T. ; Gillin, W. P. ; Suter, A. ; Morley, N. A. ; Malik, Vivek Kumar ; Dubroka, Adam ; Kim, Kyung Wan ; Bouyanfif, Houssny ; Bourqui, Francis ; Bernhard, Christian ; Scheuermann, R. ; Nieuwenhuys, G. J. ; Prokscha, T. ; Morenzoni, E.

In: Nature Materials, 2009, vol. 8, p. 109 - 114

Electronic devices that use the spin degree of freedom hold unique prospects for future technology. The performance of these 'spintronic' devices relies heavily on the efficient transfer of spin polarization across different layers and interfaces. This complex transfer process depends on individual material properties and also, most importantly, on the structural and electronic properties of the...