DOE OSTI · 2583431
Conductivity space isotherm behavior in quantum anomalous Hall devices
Abstract
The quantum Hall effect (QHE) has enhanced accessibility to measure and disseminate electrical units, owed in part to the recently redefined International System of Units in 2019. Graphene remains one of the preferred options to realize the ohm despite the limitations of high magnetic fields to produce a robust QHE. Topological insulators, on the other hand, show promise in providing quantized resistance via the quantum anomalous Hall effect, a phenomenon that removes the need for magnetic fields during operation. To optimize future devices for metrological applications, it is important to gain a better understanding of magnetically doped topological insulators like Cr-doped bismuth antimony telluride. The application of differential conductivity space analyses offers a more sensitive way to analyze the data and distinguish between 2D and 3D transport behaviors. This is particularly important in thin films, where the transition between 2D and 3D behavior can be subtle. The ability to confidently determine the dimensionality of the transport is crucial for selecting appropriate theoretical models for future device optimization. Furthermore, this work identifies variable range hopping as the dominant transport mechanism in the 2D regime using a rigorous statistical analysis (via the Bayes factor). These elements assist in the understanding of microscopic processes that govern charge transport in these materials.
Keep this discovery
Explore connections, maps & timelines
Tran, N. T. M. [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Univ. of Maryland, College Park, MD (United States)] (ORCID:000000030346986X), Ortiz Jimenez, V. [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)] (ORCID:0009000542744838), Musso, M. [Politecnico di Torino (Italy)] (ORCID:0009000918978828), Rodenbach, L. K. [Stanford Univ., CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES)] (ORCID:0000000193545752), Andersen, M. P. [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES); Stanford Univ., CA (United States)] (ORCID:0000000312749791), Hill, H. M. [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)] (ORCID:0000000248015864), Zhang, P. [Univ. of California, Los Angeles, CA (United States)], Tai, L. [Univ. of California, Los Angeles, CA (United States)] (ORCID:0000000151447337), Wang, K. L. [Univ. of California, Los Angeles, CA (United States)] (ORCID:0000000293631279), Marzano, M. [Istituto Nazionale di Ricerca Metrologica (INRiM), Torino (Italy)] (ORCID:0000000152883093), Ortolano, M. [Politecnico di Torino (Italy)] (ORCID:0000000272178276), Newell, D. B. [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)], Richter, C. A. [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)], Rigosi, Albert F. [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)] (ORCID:0000000281893829). 2025-07-10. Conductivity space isotherm behavior in quantum anomalous Hall devices. https://doi.org/10.1063/5.0278373
Cite the original work for its findings. Save a collection to share your selection of sources.