Jagadeesh Subbaiah Moodera is an American physicist of Indian origin and is senior research scientist at MIT's Francis Bitter Magnet Laboratory. In 1994 he led an MIT research team in the discovery of a practical way to implement room temperature magnetic tunnel junction (MTJ) using a magnetic stack based on CoFe–Al2O3–Co, demonstrating a tunnel magnetoresistance ratio (TMR) of 11.8%.
Low temperature magnetoresistive tunneling had been discovered by Michel Julliere in 1975 but it would be more than a decade before a room temp system was found. In 1991, Terunobu Miyazaki and others at Tohoku University had demonstrated a MTJ with room temp TMR of 2.7% but this effect was too small to be of use in practical devices. In 1994, Miyazaki's team, working independently of Moodera's, also developed a room temperature MTJ with high TMR (18.0%) based on an Fe–Al2O3–Fe stack, thus garnering recognition as co-developer of room temp magnetoresistive tunnelling along with Moodera.
Besides its great fundamental interest, room temperature magnetoresistive tunnelling is the basis for practical devices including MRAM and read heads used in hard disks. Moodera was named a Fellow of the American Physical Society in 2000 "for pioneering and sustained contributions to the understanding of spin-polarized transport in solids." Before investigating ferromagnetic tunneling, Moodera worked for many years on spin-polarized tunneling in superconductor junctions along with Bob Meservey and Paul Tedrow. Moodera, Meservey, Tedrow and Miyazaki shared the 2009 Oliver E. Buckley Condensed Matter Prize "for pioneering work in the field of spin-dependent tunneling and for the application of these phenomena to the field of magnetoelectronics."
Born in Bangalore, India, Moodera attended Mysore University (B.S. and M.S.) and the Indian Institute of Technology (Ph.D.). He was briefly at West Virginia University before joining the Francis Bitter Magnet Laboratory staff at MIT in 1981.
- J. S. Moodera, L. R. Kinder, T. M. Wong, and R. Meservey, “Large Magnetoresistance at Room Temperature in Ferromagnetic Thin Film Tunnel Junctions,” Phys. Rev. Lett. 74, 3273, 1995.
- J.S. Moodera, J. Nassar and G. Mathon, "Spin-Tunneling in Ferromagnetic Junctions," Annual Review of Materials Science 29: 381, 1999.