We present a detailed study of vortex core spectroscopy in slightly overdoped Bi2Sr2CaCu2O8 using a low temperature scanning tunneling microscope. Inside the vortex core we observe a four-fold symmetric modulation of the local density of states with an energy-independent period of (4.3\pm 0.3)a0. Furthermore we demonstrate that this square modulation is related to the vortex core states which are located at ~6 meV. Since the core-state energy is proportional to the superconducting gap magnitude, our results strongly suggest the existence of a direct relation between the superconducting state and the local electronic modulations in the vortex core.
@article{arxiv.cond-mat/0503219,
title = {Four-fold structure of vortex core states in Bi2Sr2CaCu2O8 (Bi2212)},
author = {Giorgio Levy and Martin Kugler and Alfred A. Manuel and Oystein Fischer and Ming Li},
journal= {arXiv preprint arXiv:cond-mat/0503219},
year = {2009}
}
Comments
5 pages, 4 figures. Submitted to Physical Review Letters