Effects of Microwave Frequency on a Topological-Insulator-Based Quantum Resistance Standard
ORAL
Abstract
This work examines the properties of a chromium-doped Bismuth Antimony Telluride quantum anomalous Hall (QAH) resistor, particularly its interaction with a programmable Josephson voltage standard (PJVS) in a zero-field environment. We investigate the impact of microwave frequencies, used to bias the PJVS, on the quantization of the QAH resistor. Precision measurements of the QAH resistance were conducted under both microwave exposure and standard conditions to assess any deviations from the expected quantized state.
Our results show that at the highest current of 250 nA, the relative difference in the Hall resistance measurement increased to a few parts in 106 from the baseline Hall resistance, whereas the longitudinal resistance increased by approximately 20 times that amount. This observation may be due to the heating effects of RF leakage. Additionally, variations in microwave frequency were observed to cause differing heating effects on the resistance measurements. A thorough understanding of these phenomena is crucial for optimizing the experimental setup and enabling the successful integration of multiple standards within a single cryostat.
Our results show that at the highest current of 250 nA, the relative difference in the Hall resistance measurement increased to a few parts in 106 from the baseline Hall resistance, whereas the longitudinal resistance increased by approximately 20 times that amount. This observation may be due to the heating effects of RF leakage. Additionally, variations in microwave frequency were observed to cause differing heating effects on the resistance measurements. A thorough understanding of these phenomena is crucial for optimizing the experimental setup and enabling the successful integration of multiple standards within a single cryostat.
*We acknowledge support from the Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division, under Contract DE-AC02-76SF00515. Work presented herein was performed, for a subset of the authors, as part of their official duties for the United States Government. Funding is hence appropriated by the United States Congress directly.
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Presenters
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Ngoc Thanh Mai Tran
- University of Maryland College Park
- University of Maryland
- Joint Quantum Institute, University of Maryland