Research with the Manfra Lab
I spent over two years doing research in the Manfra lab, doing investigations into topological materials that are useful in quantum computing. Below are some of the main projects I undertook in the Manfra Lab.
From my first project. A graph of the magnetoresistance oscillations as a function of magnetic field. (For more information, feel free to contact me!)
For my first project in the lab, I found the effect of varying metal alloy top barriers on the effective mass of quantum well electrons. Finding the effective masses of these samples is useful, since the effective mass of the quantum well electrons helps to determine whether or not the material is in a topological regime. In being in this regime, the material can be used to create qubits and other devices used in quantum computing. To find the effective mass, I measured the temperature dependence of the device’s magnetoresistance and extracted the effective mass data using a program I developed in MATLAB. The results of this project were presented at the 2019 Undergraduate Fall Research Expo.
In the second project with the Manfra Lab, I characterized the effects that different substrate buffer layers had on shallow quantum wells. I took magnetotransport data at 300 mK in a Helium-3 based system to characterize the samples and obtain different device parameters. Through my work, it was found that electron mobility was largely unaffected by the different buffer layers while the surface morphology was changed, implying increased ability to tune the device’s structure. The results I obtained are being included in a paper that has implications on methodologies for fabricating semiconductors used in Majorana zero-mode devices.
For my third project in the lab and my Senior Thesis* project, I measured the quantum lifetime as a function of density for the samples with different buffer layers I analyzed in the previous project. Like last time, I took magnetotransport data at 300 mK in a Helium-3 based system, but now focusing more on the low-field resistive oscillations to give the quantum lifetime of the electrons. After obtaining these oscillations, I analyzed them via a program I developed, allowing for comparison of the quantum lifetimes for the different buffer layers. The experimental data will be used to better characterize the long-range scattering defects in the samples studied and will help in making the decision as to the direction of future projects.
From my Senior Thesis. A graph of the ratio of the transport lifetimes to quantum lifetimes as a function of electron density for the different samples tested in this study. (For more information, feel free to contact me!)
*Note that I’m currently editing my thesis for inclusion on this page for viewers to read.