Induced quantum dot probe for materials characterization
Hilary M. Hurst, Yun-Pil Shim, Rusko Ruskov, Charles Tahan
We propose a non-destructive means of characterizing a semiconductor wafer via measuring parameters of an induced quantum dot on the material system of interest with a separate probe chip that can also house the measurement circuitry. We show that a single wire can create the dot, determine if an electron is present, and be used to measure critical device parameters. Adding more wires enables more complicated (potentially multi-dot) systems and measurements. As one application for this concept we consider silicon metal-oxide-semiconductor (MOS) and silicon/silicon-germanium quantum dot qubits relevant to quantum computing and show how to measure low-lying excited states (so-called \valley" states). This approach provides an alternative method for characterization of parameters that are critical for various semiconductor- based quantum dot devices without fabricating such devices.