Mentor: Veronica Stewart

Mentor's Responsibility for PARADIM:  John's Hopkins Graduate Student, McQueen Lab

REU intern:  Bryce Coyne

Veronica Stewart is a fourth-year PhD student in Chemistry at Johns Hopkins University, working with Professor Tyrel McQueen. Veronica’s research focuses on the synthesis and characterization of potential axion insulator materials. She previously attended Reed College, where she worked on sol-gel materials for lithium ion battery cathodes.

Project Title: 

Screening of MnBi₂Te₄ as an axion insulator through electronic structure calculations

Project Description: 

The proposed project will utilize Quantum Espresso to make band gap calculations of MnBi₂Te₄to explore its potential as an axion insulator. Band gap calculations will rely on density functional theory (DFT). Literature exists on MnBi₂Te₄that has characterized the material’s ground state as an anti-ferromagnetic topological insulator state that hosts a quantized magnetoelectric effect. This project will take a computational approach to characterize MnBi₂Te₄, and explore the effects of modified layer stacking and atomic substitution on its electronic structure. The project’s computational nature allows it to fit in the virtual format by utilizing remote work and collaboration on Quantum Espresso calculations with MARCC.

Research question that defines the REU student's project:

How do stacking modifications of layered axion insulator candidates affect their computed electronic structure?

Project plan/research task to answer the research question:

Become familiar with the use of Quantum Espresso and the literature on axion insulators. Using the MARCC computing center at JHU, calculate the band structure of  MnBi₂Te₄, and of variants with modified van der Waals layer stacking. Identify less-studied homologous materials, and compute the band structures of these materials and their stacking variants.

List of tasks to be performed by the REU student and tasks to be performed by the mentor to answer the research questions:

The tasks above will primarily be performed by the REU student, with the mentor assisting as needed with calculations and literature searches.