Field-coupled Nanomagnets Research Articles

Parametric excitations of coupled nanomagnets

We demonstrate that parametrically excited eigenmodes in nearby nanomagnets can be coupled to each other. Both positive (in-phase) and negative (anti-phase) couplings can be realized by a combination of appropriately chosen geometry and excitation field frequency. The oscillations are sufficiently stable against thermal fluctuations. The phase relation between field-coupled nanomagnets shows a hysteretic behavior with the phase relation being locked over a wide frequency range. We envision that this computational study lays the groundwork to use field-coupled nanomagnets parametrons as building blocks of logic devices, neuromorphic systems of Ising machines.

Compact modeling of perpendicular nanomagnetic logic based on threshold gates

In this work, we show that physical-based compact modeling of perpendicular Nanomagnetic Logic is crucial for the design and simulation of complex circuitry. A compact model for field-coupled nanomagnets based on an Arrhenius switching model and finite element calculations is introduced. As physical parameters have an enormous influence on the behavior of the circuit, their modeling is of great importance. Exemplarily, a 1-bit full adder based on threshold logic gates is analyzed due to its reliability. The obtained findings are used to design a pure magnetic arithmetic logic unit, which can be used for basic Boolean and logic operations.

Majority Gate for Nanomagnetic Logic With Perpendicular Magnetic Anisotropy

A majority gate for nanomagnetic logic with perpendicular magnetic anisotropy is presented. A novel technique of local focused ion beam irradiation generating artificial domain wall nucleation centers is used to enable directed signal flow and logic computation in an array of field-coupled nanomagnets. The switching behavior of the majority gate is characterized and logic operation is experimentally proven using magneto-optical and magnetic force microscopy. The findings are supported by numerical and micromagnetic simulations. Tolerance margins for fabrication and computing frequencies for correct operation are explored. The presented majority gate allows for complex, non-volatile logic with synchronous global clocking at room-temperature.

Nanomagnetic logic: compact modeling of field-coupled computing devices for system investigations

In this paper we investigate error rates of nanomagnetic logic devices with perpendicular magnetization by compact modeling. Two different types of nanomagnets for information propagation and logic computing are introduced. The switching behavior of field-coupled nanomagnets is measured and analyzed. A compact model is derived from physics and experimental results are applied to the magnetic compact model. General requirements for fabrication parameters and clocking fields for reliable operation are extracted. We perform simulations and measurements on single devices to demonstrate the accuracy of the macromodel. Simulations on complex systems show that the error rate of a field-coupled magnetic system strongly depends on the variation of the switching field and the strength of the coupling field between the nanomagnets. The error rate of a 1-bit full adder is investigated for varying dot parameters. The results demonstrate the importance of fast simulation tools for investigations on the design of nanomagnetic computing devices and systems.

Simulation of Power Gain and Dissipation in Field-Coupled Nanomagnets

Simulation of Power Gain and Dissipation in Field-Coupled Nanomagnets

Nanocomputing by field-coupled nanomagnets

Demonstrates through simulations the feasibility of using magnetically coupled nanometer-scale ferromagnetic dots for digital information processing. Microelectronic circuits provide the input and output of the magnetic nanostructure, but the signal is processed via magnetic dot-dot interactions. Logic functions can be defined by the proper placements of dots. We introduce a SPICE macromodel of interacting nanomagnets and use this tool to design and simulate the proposed nanomagnet logic units. This SPICE model allows us to simulate such magnetic information processing devices within the same framework as conventional electronic circuits.

Simulation of Field Coupled Computing Architectures Based on Magnetic Dot Arrays

In this paper, we demonstrate that field-coupled nanomagnets can be used for digital information processing. The operation of logic devices is based on a QCA-like architecture, where information propagates by magnetostatic interaction between individual magnetic dots. Micromagnetic simulations indicate that simple logic gates function properly. Efficient design tools, based on the single-domain approximation are developed.