Device for biasing bubble domains

A device having a film of bubble material on a substrate and adapted for the use in an external bias field between 0 and 0.4 (4.pi.M.sub.s) comprising:

• a first channel in said film having a first stripe domain therein, said first channel being of sufficient width to permit said first stripe domain to expand in width when said external bias field is lowered wherein the flux from said first stripe increases to counteract the effect of the lower external bias field,
• a second channel in said film having a second stripe domain therein, said second channel being parallel to said first channel, said second channel being of sufficient width to permit said second stripe domain to expand in width when said external bias field is lowered wherein the flux from said second stripe increases to counteract the effect of the lower external bias field,
• a third channel in said film positioned between said first channel and said second channel and adapted for the movement of a bubble there-through,
• a first conductor in juxtaposition with said first channel and said third channel and adapted for the current therein to flow in a first direction, said first conductor fixing the position of said first stripe domain in said first channel and causing said first stripe domain to expand in width in said first channel, and
• a second conductor in juxtaposition with said second channel and said third channel and adapted for the current therein to flow in a direction opposite said first direction, said second conductor fixing the position of said second stripe domain in said second channel and causing said second stripe domain to expand in width in said second channel, wherein the passage of current through said first and second conductors and the presence of said first and second stripe domains provide a biasing field around said third channel to increase the operating margin of said device.