Electrostatic force spectroscopy and imaging of Bi wires: Spatially resolved quantum confinement

We demonstrate that scanning probe electrostatic force microscopy applied to a nanoscale electronic structure can be used for studying the spatially resolved carrier quantized states as determined by the screening properties of local surface regions of the structure. The results presented for the cross-sectional surface of Bi quantum wires elucidate the microscopic nature of quasi-one-dimensional confined states excited by an applied bias voltage, where the single-particle-in-a-box energy quantization competes with the wire boundary enhanced intercarrier Coulomb repulsion.