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 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.
@article{arxiv.1809.03523,
title = {Induced quantum dot probe for material characterization},
author = {Yun-Pil Shim and Rusko Ruskov and Hilary M. Hurst and Charles Tahan},
journal= {arXiv preprint arXiv:1809.03523},
year = {2019}
}