Induced quantum dot probe for material characterization

TL;DR

This paper introduces a non-destructive method using induced quantum dots on a probe chip to characterize semiconductor materials and quantum dot qubits, enabling measurement of critical parameters without device fabrication.

Contribution

It presents a novel, non-invasive technique for material and device characterization using induced quantum dots with a simple probe chip, applicable to quantum computing components.

Findings

Single wire can create and detect quantum dots and measure device parameters.

Multiple wires enable complex multi-dot systems and measurements.

Method applicable to silicon quantum dot qubits for valley state analysis.

Abstract

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.