An Energy-Efficient Bennett Clocking Scheme for 4-State Multiferroic Logic

TL;DR

This paper proposes an energy-efficient Bennett clocking scheme for 4-state multiferroic nanomagnet logic gates, enabling unidirectional propagation of 4-state logic bits with low voltage control.

Contribution

It introduces a novel Bennett clocking method using strain-mediated multiferroic nanomagnets for 4-state logic, enhancing energy efficiency and unidirectional data flow.

Findings

A voltage of 200 mV can rotate magnetization states in multiferroic nanomagnets.

A specific voltage sequence enables unidirectional logic bit propagation.

The scheme demonstrates potential for low-power multiferroic logic circuits.

Abstract

Nanomagnets with biaxial magnetocrystalline anisotropy have four stable magnetization orientations that can encode 4-state logic bits (00), (01), (11) and (10). Recently, a 4-state NOR gate derived from three such nanomagnets, interacting via dipole interaction, was proposed. Here, we devise a Bennett clocking scheme to propagate 4-state logic bits unidirectionally between such gates. The nanomagnets are assumed to be made of 2-phase strain-coupled magnetostrictive/piezoelectric multiferroic elements, such as nickel and lead zirconate titanate (PZT). A small voltage of 200 mV applied across the piezoelectric layer can generate enough mechanical stress in the magnetostrictive layer to rotate its magnetization away from one of the four stable orientations and implement Bennett clocking. We show that a particular sequence of positive and negative voltages will propagate 4-state logic bits unidirectionally down a chain of such multiferroic nanomagnets for logic flow.