Group Seminar 2025/26

ABSTRACT: Conventional CMOS-based memory architectures face well-known trade-offs
between speed, endurance, volatility, and write energy, which impose critical
limitations on AI computing efficiency. In response, this seminar presents our
systematic research on spintronic memory elements, specifically spin valves and
magnetic tunnel junctions (MTJs), as promising building blocks for future
non-volatile, low-power memory systems that can overcome these inherent CMOS
constraints.

Among various spintronic structures, those based on van der Waals (vdW)
heterojunctions are of particular interest, as their atomically sharp interfaces and
exceptional spin-transport properties offer distinct advantages over conventional
polycrystalline or amorphous barriers. These features make vdW-based devices highly
attractive for non-volatile magnetic random-access memories and high-density
magnetic recording. Nevertheless, a long-standing obstacle to their practical
implementation has been the lack of room-temperature intrinsic ferromagnets with
perpendicular magnetic anisotropy, which is essential for realizing vertical spin valves
with high thermal stability and scalability. This barrier has recently been removed by
the discovery of the two-dimensional vdW ferromagnet Fe3GaTe2, which exhibits
intrinsic room-temperature ferromagnetism and strong perpendicular anisotropy.
Building directly upon this breakthrough, we have fabricated Fe3GaTe2-based spin
valves and MTJs, employing Fe3GaTe2 as the ferromagnetic electrodes and a range of
semiconductor materials as tunable tunneling barriers.

To optimize device performance, we systematically investigate the effects of several
key parameters, including interlayer material type and thickness, operating
temperature, electric field, and magnetic electrode composition. Beyond empirical
characterization, we further analyze the underlying physical mechanisms governing
different magnetoresistance responses, thereby establishing clear structure-property
relationships that guide material and device design. Ultimately, by integrating
experimental findings with mechanistic understanding, we assess the viability of these
vdW spintronic devices for high-density, low-power magnetic memory and spin-based
logic applications, providing a pathway toward next-generation information storage
and processing