Ultrathin All‐in‐One Spin Hall Magnetic Sensor with Built‐In AC Excitation Enabled by Spin Current. Issue 8 (15th July 2018)

• Record Type: Journal Article
• Authors: Xu, Yanjun; Yang, Yumeng; Zhang, Mengzhen; Luo, Ziyan; Wu, Yihong
• Is Part Of: Advanced materials technologies. Volume 3:Issue 8(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-07-15
• Subjects: AC excitation -- spin current -- spin‐Hall magnetoresistance sensor -- spin–orbit torque; Materials science -- Periodicals; Technological innovations -- Periodicals; Materials science; Technological innovations; Periodicals; 620.1105
• DOI: 10.1002/admt.201800073
• Languages: English
• ISSNs: 2365-709X

Abstract

Abstract: Magnetoresistance (MR) sensors provide cost‐effective solutions for diverse industrial and consumer applications, including emerging fields such as internet‐of‐things (IoT), artificial intelligence, and smart living. Commercially available MR sensors such as anisotropic magnetoresistance (AMR) sensors, giant magnetoresistance (GMR) sensors, and tunnel magnetoresistance (TMR) sensors typically require an appropriate magnetic bias for both output linearization and noise suppression, resulting in increased structural complexity and manufacturing cost. Here, an all‐in‐one spin Hall magnetoresistance (SMR) sensor with built‐in AC excitation and rectification detection is demonstrated, which effectively eliminates the requirements of any linearization and domain stabilization mechanisms separated from the active sensing layer. This is made possible by the coexistence of SMR and spin–orbit torque (SOT) in ultrathin NiFe/Pt bilayers. Despite the simplest possible structure, the fabricated Wheatstone bridge sensor exhibits essentially zero DC offset, negligible hysteresis, and a detectivity of around 1 nT Hz −1/2 at 1 Hz. In addition, it also shows an angle dependence to external field similar to those of GMR and TMR, though it does not have any reference layer (unlike GMR and TMR). The superior performances of SMR sensors are evidently demonstrated in the proof‐of‐concept experiments on rotation angle measurement, and vibration and finger motion detection. Abstract : An all‐in‐one spin Hall magnetic sensor that features simplest structure, nearly zero DC offset, negligible hysteresis, and low noise based on AC excitation is demonstrated. A few proof‐of‐concept potential applications including angle, vibration, and finger movement detection are demonstrated. The work opens new possibilities for further exploitation of spin–orbit torque technology in a wide range of applications.