Tunable microwave properties of rhomboid shaped nanomagnet pairs

Nanomagnet-based memory and logic operations have attracted great technological interest in recent years due to their nonvolatility, low-power logic operations, ultrahigh density, and high endurance [1], [2]. They are regarded as potential candidates for the next generation of non-volatile, low power logic devices beyond conventional CMOS technology. Recently, reconfigurable microwave responses have been shown based on in-plane dipolar coupled rhomboid shaped nanomagnets (RNMs) which do not require any stand-by power once initialized [3]. To optimize the frequency difference between ferromagnetic (FM) and antiferromagnetic (AFM) ground states, multilayer RNMs with a relatively thin nonmagnetic spacer layer have been investigated in which the nanomagnets are strongly out-of-plane dipolar coupled, and therefore a distinct frequency difference $(\Delta f \sim 1.9$ GHz) is achieved [4]. We may obtain a more complex relation of the magnetic ground state with the initialization field and intriguing magnetization dynamics at remanence by incorporating both in-plane and out-of-plane dipolar coupling in RNM-based structures. Thus, an understanding of the static and dynamic magnetic properties of the multilayer RNM pair in which the nanomagnets are both in-plane and out-of-plane dipolar coupled would be of great interest.