Topologically Protected Magnetic Helix for All-Spin-Based Applications

The recent years have witnessed an emergence of the field of all-spin-based devices without any flow of charge. An ultimate goal of this scientific direction is the realization of full spectrum of spin-based networks like in modern electronics. The concepts of energy storing elements, indispensable for those networks, are so far lacking. Analyzing analytically the size dependent properties of magnetic chains that are coupled via either exchange or long-range dipolar or Ruderman-Kittel-Kasuya-Yosida interactions, we discover a particularly simple law: magnetic configurations corresponding to helices with integer number of twists, that are commensurate with the chain's length, are energetically stable. This finding, supported by simulations and an experimentally benchmarked model, agrees with the study [J. Appl. Phys. \textbf{111}, 07E116 (2012)] showing that boundaries can topologically stabilize structures that are not stable otherwise. On that basis an energy storing element is proposed.