Experimental Clocking of Nanomagnets with Strain for Ultralow Power Boolean Logic

Abstract

Nanomagnetic implementations of Boolean logic have attracted attention because of their nonvolatility and the potential for unprecedented overall energy-efficiency. Unfortunately, the large dissipative losses that occur when nanomagnets are switched with a magnetic field or spin-transfer-torque severely compromise the energy-efficiency. Recently, there have been experimental reports of utilizing the Spin Hall effect for switching magnets, and theoretical proposals for strain induced switching of single-domain magnetostrictive nanomagnets, that might reduce the dissipative losses significantly. Here, we experimentally demonstrate, for the first time that strain-induced switching of single-domain magnetostrictive nanomagnets of lateral dimensions ∼200 nm fabricated on a piezoelectric substrate can implement a nanomagnetic Boolean NOT gate and steer bit information unidirectionally in dipole-coupled nanomagnet chains. On the basis of the experimental results with bulk PMN-PT substrates, we estimate that the energy dissipation for logic operations in a reasonably scaled system using thin films will be a mere ∼1 aJ/bit.

Giant voltage manipulation of MgO-based magnetic tunnel junctions via localized anisotropic strain: A potential pathway to ultra-energy-efficient memory technology

“…[27][28][29][30] There are also several theoretical predications 31-33 that such a method will dissipate only a few atto-Joules (aJ) of energy to write data. This establishes the promise of using strain to control the resistance of an MTJ for ultra-energy-efficient memory applications.…”

“…[16][17][18][19][20][21] It has been widely investigated in various piezoelectric/ferromagnetic bilayer thin films [22][23][24][25][26] or nano-structures. [27][28][29][30] There are also several theoretical predications [31][32][33] that such a method will dissipate only a few atto-Joules (aJ) of energy to write data. This establishes the promise of using strain to control the resistance of an MTJ for ultra-energy-efficient memory applications.…”

Static and Dynamic Magnetic Properties of Sputtered Fe–Ga Thin Films

“…A series of new experiments have shown the possibility of strain–mediated switching in Co [17]–[19] and FeGa-alloy based nanomagnets [20]. While transition metal ferromagnets (Fe, Co, Ni) exhibit relatively modest bulk magnetostriction coefficients (∼ 10 −5 ), binary and ternary alloys such as Fe 0.81 Ga 0.19 (Galfenol) and Tb 0.3 Dy 0.7 Fe 2 (Terfenol-D) exhibit magnetostriction coefficients nearly ten times higher for particular stoichiometric compositions [21], [22].…”

Magnetic skyrmion bubble motion driven by surface acoustic waves

“…27,28 Such studies pave the way for various applications in magnetic memory and logic devices. 26,32,33 In this work, we explore a skyrmion bubble dynamics induced by counter-propagating SAWs. To properly describe the dynamics, we introduce a finite skyrmion bubble mass.…”