Rehman, Mushtaq Park, Jung Hwan Song, Woon Chong, Yonuk Lee, Yeon-Sub Min, Byoung-Chul Shin, Kyung-Ho Ryu, Sang-Wan Khim, Zheong G. 2024-01-20T18:32:20Z 2024-01-20T18:32:20Z 2021-09-05 2010-10 0374-4884 https://pubs.kist.re.kr/handle/201004/131061 We measured the noise power of a magnetic tunnel junction in the frequency range of 710 similar to 1200 MHz. A low-noise cryogenic HEMT amplifier was used to measure the small noise signal at a high frequency with wide bandwidth. The MgO-barrier tunnel junction showed large tunnel magnetoresistance ratio of 215% at low temperature, which indicates electronic transport through the tunnel barrier without any significant spin-flip scattering. In the bias-dependent noise measurement, however, the zero-bias shot noise was enhanced compared to the value expected from a perfect tunnel barrier or the value observed from a good Al-AlOx-Al tunnel junction. We assume that this enhanced noise comes from inelastic tunneling processes through the barrier, which may be related to the observed zero-bias anomaly in the differential resistance of the tunnel junctions. We present a simple phenomenological model for how the inelastic scattering process can enhance the zero-bias noise in a tunnel junction. English KOREAN PHYSICAL SOC Radio-frequency Shot-noise Measurement in a Magnetic Tunnel Junction with a MgO Barrier Article 10.3938/jkps.57.818 1 JOURNAL OF THE KOREAN PHYSICAL SOCIETY, v.57, no.4, pp.818 - 822 JOURNAL OF THE KOREAN PHYSICAL SOCIETY 57 4 818 822 scie scopus kci ART001488840 000283108900022 2-s2.0-78149399458 Physics, Multidisciplinary Physics Article ROOM-TEMPERATURE MAGNETORESISTANCE Magnetic tunnel junction Spintronics Noise