Abstract
Scanning tunneling microscopy (STM) has been performed on underdoped Ca2−x Na x CuO2Cl2 (Na-CCOC) single crystals to investigate the electronic states of doped Mott insulators near the metal-insulator transition. STM images taken at 7 K show patch-like or river-like irregular features superposed on the atomic corrugations. The irregular structure has a characteristic length scale of ∼20 Å, which is unchanged in different samples and at different doping levels studied (0.08<x<0.12). Bias voltage dependence of the STM image suggests that Na-CCOC consists of two distinct phases with different electronic states.
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Kohsaka, Y., Hanaguri, T., Kitazawa, K. et al. Real Space Imaging of the Electronic States in Underdoped Ca2−x Na x CuO2Cl2 Single Crystals. Journal of Low Temperature Physics 131, 299–303 (2003). https://doi.org/10.1023/A:1022941506435
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DOI: https://doi.org/10.1023/A:1022941506435