1. Low frequency 1/f noise in deep submicrometer-sized magnetic tunnel junctions.
- Author
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Anh Nguyen, T. N., Pham, Q. N., Fukumoto, M., Goto, M., Okuno, R., Tomita, H., Kubota, H., Fukushima, A., Yakushiji, K., Watakabe, T., Hasebe, S., Lam, D. D., Do, K. T., Nguyen, T. H., Vu, H. K., Vu, D. L., and Suzuki, Y.
- Subjects
PINK noise ,MAGNETIC tunnelling ,NOISE measurement ,MAGNETIC sensors ,THERMAL noise - Abstract
Magnetic tunnel junctions (MTJs) have been identified as promising candidates for the development of high-performance, ultra-low field magnetometers due to their high sensitivity, low cost, low power consumption, and small size. However, 1/f noise is often quite large at low frequencies and inevitably becomes one of the most difficult issues in developing a magnetic field sensor with ultrahigh sensitivity. Low-frequency 1/f noise can have both electric and magnetic origins, and it is a result of complex non-linear interactions between many degrees of freedom inside a sensor. Therefore, a reduction of the 1/f noise can be expected for the magnetic sensor with very small dimensions. Here, the dependence of the 1/f noise on voltage and strong hard-axis bias field in deep submicrometer-sized MgO-based MTJs is investigated with various junction sizes. The noise spectra were measured by using a home-built low-frequency noise measurement setup with maximum frequency up to 30 kHz. We find that the noise spectral power density is 1/f-like at low frequencies. The experimental results suggest a relative reduction of 1/f noise with respect to the intrinsic thermal noise in small-sized MTJs. The results may open a new approach for reducing the 1/f noise level in MTJ nanosensors. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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