Tunable Magnetic Tunnel Junction with Optical Output
Ravi Saraf
Collaborator Evgeny Tsymbal
This project is aimed at fabricating and studying magnetic tunnel junctions (MTJs) with a tunable barrier thickness and an optical output mapping a magnetic domain structure of a magnetic thin film or a layer of nanoparticles. This research is addressing two fundamental physical phenomena:
1) tunneling magneto-resistance (TMR) in a MTJ based on a polymer barrier with pressure-controlled variable thickness and
2) imaging the magnetization distribution by conversion to optical signal at less than 10 mm resolution over an area of a few cm2.
This research is built on our recent successful demonstration of an electron tunneling device of 6 cm2 area capable of imaging modulation in current distribution due to stress by converting local strain into electroluminescent light.
a)
b)
Stress-sensitive magnetic tunnel junction with optical detection: (a) MTJ structure; (b) device geometry.