1. A method for forming a magnetic tunnel junction (MTJ) circuit, the method comprising: forming a plurality of magnetic tunnel junction (MTJ) stacks, wherein each of the plurality of MTJ stacks includes a tunnel oxide layer between a free layer and a fixed layer; and forming a stress-inducing layer above each free layer; wherein: a first free layer of a first MTJ stack from the plurality of MTJ stacks is stressed to a first extent by a first stress-inducing layer of the first MTJ stack; a second free layer of a second MTJ stack from the plurality of MTJ stacks is stressed to a second extent by a second stress-inducing layer of the second MTJ stack; and the first extent and the second extent are different.