Liquid crystals on graphite have been observed by scanning tunneling microscopy. Although an isolated 4hyphen;nhyphen;octylhyphen;4rsquo;hyphen;cyanobiphenyl (8CB) molecule shows a wide 11 eV energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), its image could be obtained by tunneling bias around 800 mV far below this energy gap. The fact that 8CB with a large energy gap could be imaged was confirmed by a spectroscopic measurement. This LC molecule visualizing mechanism is interpreted from one viewpoint as the result of energy level shift possibly caused by moleculehyphen;substrate interaction and from another viewpoint as the result of periodic molecules forming an energy band.
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