Jw is a write current density, t is {HEAD ~ a thickness} of {TAIL ~ the free layer}, A is a constant 
Jw is a write current density , t is { HEAD ~ a thickness } of { TAIL ~ the free layer } , A is a constant
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH