arXiv subjects

K. Goss

Publications and source records attributed to K. Goss.

2 recordsLinked to original sources

arXiv2011

Photoemission of a doped Mott insulator: spectral weight transfer and qualitative Mott-Hubbard description

The spectral weight evolution of the low-dimensional Mott insulator TiOCl upon alkali-metal dosing has been studied by photoelectron spectroscopy. We observe a spectral weight transfer between the lower Hubbard band and an additional peak upon electron-doping, in line with quantitative expectations in the atomic limit for changing the number of singly and doubly occupied sites. This observation is an unconditional hallmark of correlated bands and has not been reported before. In contrast, the absence of a metallic quasiparticle peak can be traced back to a simple one-particle effect.

cond-mat.str-el↗

arXiv2009

Profiling the interface electron gas of LaAlO3/SrTiO3 heterostructures by hard X-ray photoelectron spectroscopy

The conducting interface of LaAlO$_3$/SrTiO$_3$ heterostructures has been studied by hard X-ray photoelectron spectroscopy. From the Ti~2$p$ signal and its angle-dependence we derive that the thickness of the electron gas is much smaller than the probing depth of 4 nm and that the carrier densities vary with increasing number of LaAlO$_3$ overlayers. Our results point to an electronic reconstruction in the LaAlO$_3$ overlayer as the driving mechanism for the conducting interface and corroborate the recent interpretation of the superconducting ground state as being of the Berezinskii-Kosterlitz-Thouless type.

cond-mat.str-el↗