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Magnetic Noise in a Low-Power Picotesla Magnetoresistive Sensor



Stephen E. Russek, Lu Yuan, Sean Halloran, Fabio C. da Silva, David P. Pappas, John M. Moreland, Sy-hwang Liou, Rui Zhang


We present a design of a low power, compact, magnetoresistive sensor. The key features of the design are(1) decreasing the noise by the use of a 64 element magnetic tunnel junction (MTJ) bridge,(2) reducing the magnetic noise by annealing the MTJ sensors in high magnetic field and a hydrogen environment, and (3) increasing signal by the use of external low-noise magnetic flux concentrators. The field noise of our prototype magnetic sensor is approximately 1 pT/Hz1/2 at 1 kHz, 5 pT/Hz1/2 at 10 Hz, and 50 pT/Hz1/2 at 1 Hz at room temperature. The magnetic sensor only dissipates 15 mW of power while operating.
Applied Physics Letters


magnetic sensor, magnetic tunneling junction, magnetic concentrators, magnetic noise


Russek, S. , Yuan, L. , Halloran, S. , Da, F. , Pappas, D. , Moreland, J. , Liou, S. and Zhang, R. (2009), Magnetic Noise in a Low-Power Picotesla Magnetoresistive Sensor, Applied Physics Letters, [online], (Accessed April 15, 2024)
Created October 24, 2009, Updated October 13, 2020