Tuning the Chiral Anomaly in Topological Semimetal via Ion Implantation: Pathway to Design Quantum Materials
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CordovaCarrizales-denisse-sm-nse-2026-thesis.pdf
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4.93 MB
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3c80daf4a309d6be3c3ae78d4ef4ace5
Author(s)
Carrizales, Denisse Córdova
Advisor(s)
Li, Mingda
Date Issued
February 2026
Publisher
Massachusetts Institute of Technology
Abstract
Topological semimetals are a class of quantum materials where unusual charge transport can occur due to the Adler–Bell–Jackiw chiral anomaly. Signatures of this effect can be observed in condensed matter systems as negative longitudinal magnetoresistance (NLMR), where counterintuitively electrical resistance decreases under parallel electric and magnetic fields. To enhance NLMR, we implant niobium ions into cadmium arsenide (Cd₃As₂) thin films through fast ion implantation. This accelerator-based approach, commonly used in semiconductor and nuclear materials research but rarely for topological quantum materials, allows us to tune the electronic structure while preserving the material’s crystallinity. We observe over a 100% relative enhancement of the minimum NLMR compared to pristine Cd3As2 thin films, demonstrating that disorder introduced in a controlled way can strengthen, rather than suppress, quantum transport signatures. By establishing a tuning knob for NLMR via fast-ion implantation in Cd₃As₂, we demonstrate a pathway for the design of quantum materials.
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
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