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Detection of individual spin species via frequency-modulated charge pumping



James Ashton, Mark Anders, Jason Ryan


We utilize the recently developed frequency-modulated charge pumping technique to detect a single charge per cycle, which strongly suggests a single Si/SiO2 interface trap. This demonstration in sub-micron MOSFETs, in which scaling of the gate oxide yields lethal oxide leakage currents, eliminates interference of the charge pumping current from the leakage phenomenon. By modulating the charge pumping gate pulse between high and low frequency, we are able to reliably and easily measure single-trap charge pumping, which would otherwise be completely obscured by oxide leakage. This work provides a unique avenue for single-trap detection, which can be applied to more modern commercial ultra-scaled MOS devices as a standard of electrical current as well as serve as a useful platform for developing quantum engineering technologies.
Applied Physics Letters


Charge Pumping, Silicon, Single trap


Ashton, J. , Anders, M. and Ryan, J. (2022), Detection of individual spin species via frequency-modulated charge pumping, Applied Physics Letters, [online],, (Accessed April 23, 2024)
Created February 2, 2022, Updated November 29, 2022