Popis radova laboratorija
U utorak 26.6. s početkom u 14:15 sati dr. sc. Hans-Joachim Grafe sa Leibniz Institute for Solid State Research, Dresden (Njemačka) će u sklopu projekta SOLeNeMaR održati seminar pod naslovom "New NMR results in the prototypical high temperature superconductors La2-xSrxCuO4 and YBa2Cu3Oy ".
Seminar će se održati na Fizičkom odsjeku, soba 201 (I. kat), a sažetak seminara se nalazi u nastavku obavijesti:
"Even after 25 years of intense research on the high temperature superconducting cuprates it is still possible to either prove findings which were not generally accepted, or even to find totally new results which were not known before. In my talk, I will present new NMR results on the prototypical HTSC compounds La2-xSrxCuO4 and YBa2Cu3Oy. In the first compound, we could recently prove that the average low temperature orthorhombic structure as determined by x-ray scattering is fully compatible with its local structure determined by a local probe as NMR [1]. In the second compound, we explored the highly underdoped regime (y=6.35-6.6), and found a new NMR signal which proves the emergence of a static order below a critical hole doping of pc~0.095 [2]. Surprisingly, the pseudogap as determined by the NMR spin lattice relaxation appears only above this critical doping level. Our data suggests that a possibly stripe-like static order competes with the spin-pseudogap phase, whereby both are separated by a critical hole doping pc .
[1] S.-H. Baek, A. Erb, B. Büchner, and H.-J. Grafe, Phys. Rev. B 85, 184508 (2012)
[2] S.-H. Baek, T. Loew, V. Hinkov, C. T. Lin, B. Keimer, B. Büchner, and H.-J. Grafe, to be published"