We have investigated the effects of modification of the SrTiO3/Co interface as well as the SrTiO3 barrier on the tunnel magnetoresistance TMR of La0.67Sr0.33MnO3/SrTiO3/Co junctions. Modification was realized by the introduction of one atomic layer of either TiO2 or SrO at the SrTiO3/Co interface. Barriers with different oxygen content were also studied. In these structures we have observed pos...

Computers built of naturally probabilistic bits, as envisioned by Richard Feynman, share a large class the applications anticipated for noisy intermediate-scale quantum (NISQ) computers. The authors show how basic building block highly scaled memory technology, namely familiar magnetic tunnel junction, can be straightforwardly modified making use two free layers that are each in superparamagnet...

Future generations of magnetic random access memory demand tunnel junctions that can provide simultaneously high magnetoresistance, strong retention, low switching energy and small cell size below 10nm. Here we study perpendicular with composite free layers where multiple ferromagnet/nonmagnet interfaces contribute to the thermal stability. Different nonmagnetic materials (MgO, Ta, Mo) have bee...

We present results from nanometer-scale tunnel junctions fabricated using organic self-assembled monolayers ~SAMs! as tunnel barriers. Single junctions have resistances consistent with tunneling through a single layer of molecules. In several devices, a gold nanoparticle nucleated within the SAM barrier. Such samples allow a sensitive test of mechanical stability—some are sufficiently stable to...

We demonstrate a spin diode consisting of a semiconductor-free nanoscale Fe/MgO-based double tunnel junction. The device exhibits a near perfect spin-valve effect combined with a strong diode effect. The mechanism consistent with our data is resonant tunneling through discrete states in the middle ferromagnetic layer sandwiched by tunnel barriers of different spin-dependent transparency. The ob...

Metal-insulator-metal (MIM) tunnel diodes on a variety of high and low work function metals with various levels of root-mean-square roughness are fabricated using high quality atomic layer deposited Al2O3 as the insulating tunnel barrier. It is found that electrode surface roughness can dominate the current versus voltage characteristics of MIM diodes, even overwhelming the impact of metal work...