Interface-controlled antiferromagnetic tunnel junctions provide new path for next-gen spintronics

A analysis workforce led by Prof. Shao Dingfu on the Institute of Solid State Physics, the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, has unveiled a brand new mechanism for attaining sturdy spin polarization utilizing antiferromagnetic steel interfaces.

Their findings, published in Newton just lately, suggest a 3rd prototype of antiferromagnetic tunnel junction (AFMTJ), paving the way in which for sooner and denser spintronic units.

As electronics demand smaller measurement, increased pace, and decrease power use, spintronics—utilizing each electron cost and spin—affords a powerful different to conventional units. Magnetic tunnel junctions (MTJs), a key spintronics know-how, are already utilized in information storage however face limits as a consequence of sluggish response speeds and undesirable magnetic fields from their ferromagnetic components.

Antiferromagnetic (AFM) supplies keep away from these points. They haven’t any internet magnetism, no stray fields, and far sooner spin responses, making them ideally suited for future units. However, present AFM tunnel junctions depend upon particular bulk properties, which enormously limits materials choices.

In this analysis, the workforce tackled this problem by shifting focus to interface results, which have usually been underestimated. They found that by suppressing bulk results, sure AFM supplies—significantly A-type antiferromagnets—can exhibit sturdy spin polarization at easy and steady interfaces, even when the fabric itself lacks bulk spin-split states.

Using first-principles modeling, the workforce designed a brand new AFMTJ composed of a two-dimensional A-type AFM steel (Fe₄GeTe₂) and an insulating BN barrier. Despite the spin-degenerate nature of Fe₄GeTe₂’s band construction, vital spin-polarized currents emerged as a consequence of interface-driven results. These currents remained sturdy whatever the electrode’s thickness or layer parity, confirming their interface origin.

Crucially, the junction exhibited a tunnel magnetoresistance (TMR) of almost 100%—on par with typical designs—by switching the relative orientation of the interfacial magnetic moments. This strategy expands the vary of supplies appropriate for spintronic units, particularly on condition that many AFM supplies could be grown with A-type stacking by tuning development instructions.

Commenting on the work, Prof. Jose Lado (Aalto University) and Prof. Saroj P. Dash (Chalmers University of Technology) wrote in an accompanying Newton commentary: “Uncompensated interfaces in antiferromagnets bring new opportunities for van der Waals heterostructures,” praising the research’s conceptual breakthrough and sensible significance.

This analysis not solely challenges the long-held perception that bulk results are important for AFM spintronic functions but additionally lays a basis for high-performance, interface-engineered units within the post-Moore period.