Condensed Matter Physics Seminar
Electronic Phase Separation in La2-xSrxCuO4+y
We studied an electronically driven phase separation of doped holes into separate magnetic and superconducting regions in superoxygenated La2-xSrxCuO4+y, with various Sr contents. Irrespective of Sr doping, excess oxygen raises the superconducting onset to 40 K with a coexisting magnetic spin density wave that also orders near 40 K in each of our samples. The magnetic region is closely related to the anomalous, 1/8 hole doped, magnetic versions of La2CuO4, while the superconducting region is optimally doped. The two phases are likely to be the only truly stable ground states in this region of the phase diagram. This simple two-component system represents the most direct observation of electronic phase separation in cuprate superconductors and holds the key to understanding seemingly conflicting experimental observations.
Thursday, October 20, 2005
Gant Science Complex
(The seminar is followed by coffee/tea, cookies, and an informal discussions.)