Nanomagnetic Logic: Error-Free, Directed Signal Transmission by an Inverter Chain

In this paper we present a new clocking method for non-reciprocal information transmission by an inverter chain of focused ion-beam engineered Co/Ni nanomagnets. The functionality of the clocking method is proven experimentally. Local focused ion-beam irradiation is used in order to define the direction of the information flow. The nanodots of the chain are clocked synchronously by a global external field. Information is transmitted synchronously between neighboring dots due to field-coupling. Magnetic force microscopy is used to reveal the magnetization state of the nanomagnets after every field pulse to prove the correct transmission of the signal. The switching characteristics of the fabricated nanodots and coupling forces between neighboring dots are analyzed optically using the magneto-optical Kerr effect. A detailed explanation is given for the occurrence of possible errors in a field coupled inverter chain.