We report ^{ 17}O Nuclear Magnetic Resonance (NMR) results in the stripe ordered La_{ 1.8-x}Eu_{ 0.2}Sr_{ x}CuO_4 system. Below a temperature T_q ~ 80K, the local electric field gradient (EFG) and the absolute intensity of the NMR signal of the planar O site exhibit a dramatic decrease. We interpret these results as microscopic evidence for a spatially inhomogeneous charge distribution, where the NMR signal from O sites in the domain walls of the spin density modulation are wiped out due to large hyperfine fields, and the remaining signal arises from the intervening Mott insulating regions.
Categories: cond-mat.str-el