Graduate Program Events
Events on Tuesday, October 27th, 2020
- Circuit Quantum Electrodynamics with Si/SiGe Quantum Dots
- Time: 3:00 pm
- Speaker: Nathan Holman, Physics PhD Graduate Student
- Abstract: In this talk I present an approach to engineering quantum mechanical circuits utilizing superconducting resonators and Si/SiGe quantum dots in a cQED framework as a basis for quantum computing technology. I will discuss the microwave engineering principles for the quantum dot wiring to nearly eliminate unintended resonator photon leakage out the dot leads without the use of on chip lumped element LC filters. Using this approach, quality factors as high as 30k have been achieved and are limited by the intentional coupling of the resonator to the readout lead. Next, I discuss the development and characterization of a novel growth technique for an ultrathin (< 2 nm) and high quality SiO2 gate dielectric aimed at reducing charge noise. As a demonstration of improved charge coherence, I will show low frequency (< 500 MHz) Landau-Zener-Stückelberg-Majorana interferometry experiments of a dressed valley-orbit state. Lastly, I will present ongoing efforts to further improve device performance and reproducibility by decoupling the fabrication of the quantum dots and resonators using a multi-chip module architecture. Preliminary measurements of a double and triple quantum dots coupled to an off chip, high impedance TiN resonator will be shown.
- Host: Mark Eriksson, Faculty Advisor