Université de Fribourg

Controlling the near-surface superfluid density in underdoped YBa₂Cu₃O6+x by photo-illumination

Stilp, E. ; Suter, A. ; Prokscha, T. ; Salman, Z. ; Morenzoni, E. ; Keller, H. ; Pahlke, P. ; Hühne, R. ; Bernhard, Christian ; Liang, Ruixing ; Hardy, W. N. ; Bonn, D. A. ; Baglo, J. C. ; Kiefl, R. F.

In: Scientific Reports, 2014, vol. 4, p. -

The interaction with light weakens the superconducting ground state in classical superconductors. The situation in cuprate superconductors is more complicated: illumination increases the charge carrier density, a photo-induced effect that persists below room temperature. Furthermore, systematic investigations in underdoped YBa₂Cu₃O6+x (YBCO) have shown an enhanced critical...

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...