Switching fluctuations and density limitations of pseudospin valve memory

In this article, a systematic micromagnetic analysis of the pseudospin valve magnetic random access memory device is presented. The article focuses on the correlation between switching field variation and geometric structure of the memory elements. For an elongated memory element with flat ends, magnetization reversal always initiates from the ends, yielding nonrepeatable switching processes and fluctuating switching fields. Tapering the element ends forces the reversal to start from the center region of the element and triggers robust repeatable magnetization rotation. However, sharp tips of the tapered ends are required, which may present limitations on fabrication in practice. (C) 2000 American Institute of Physics. [S0021- 8979(00)94908-9].