Date: Thursday, March 26, 2026

Time:  12:45 PM to 1:45 PM

Location: CHTM, Room 103 and Zoom

Speaker: Dr. Troy Hutchins-Delgado of Sandia National Laboratories 

Abstract:

Quantum computers have the promise of bringing an exponential growth of physical understanding and technological advancements just like the growth society has seen from classical computers. However, we are still in the infancy of quantum computers figuring out the best possible platform. Spin qubits, using gate-defined quantum dots on group IV material platforms, are one of the leading candidates. Group IV-based spin qubit devices have the major advantage of leveraging the existing silicon-based electronics industry. Group IV-based spin qubit devices also have the advantage of isotopic purification thereby significantly reducing noise due to an unwanted nuclear spin background. Just as there are various transistor types, there are various ways to implement spin qubits using gate-defined quantum dot devices. There are also many material platforms within the group IV family which to build from. Before getting qubits, the important first step is establishing high-quality starting material and verifying that it remains high-quality throughout the device fabrication process. In this talk, we discuss the characterization of Ge/SiGe, GeSn/Ge, and Sn-implanted Si-MOS material platforms. We use a variety of direct material characterization techniques including high-resolution scanning transmission electron microscopy, energy dispersive x-ray spectroscopy, x-ray diffraction, Raman spectroscopy, and atomic force microscopy. We also characterize material platforms using simple devices structures including Hall bars and MOS capacitors. We also discuss the challenges of fabricating and measuring gate-defined quantum dot devices across various material platforms.

Biography: