Spintronics technology: past, present and future

Abstract

Spintronics has emerged in the last two decades as both an extremely fruitful direction of research into the properties and usefulness of the spin degree of freedom of the electron as it can apply to the exponentially expanding world of electronics. Spintronics has infiltrated almost every household in the form of the read head sensors for the hard drives that inhabit every desktop and most laptop computers. Embedded magnetic random access memory (MRAM) and inplane STT-RAM are rapidly replacing SRAM in a host of applications that do not require ultradense memories. Soon these embedded spintronic memories will permeate the cell phone market because they are much denser than SRAM, offer lower power at only slightly lower speed and are non-volatile. The present work in spintronics at most of the mainstream semiconductor companies and foundaries is focused on the development of perpendicular STT-MRAM, as a universal memory that can compete with the mainstream memories and surpass them in several key metrics. Several innovative ideas are presented where spintronics may have an impact because of the uniqueness of the approach. Nanomagnetic logic and storage may offer extremely high densities at very low power. Spin-torque oscillators are a very novel approach to pattern recognition that may be relevant for handling massive data sets. The spin of the electron may also be on the critical path for quantum computation or communication, another revolutionary change in how we process information.

Influence of Incident Angle of Electron on Transmittance and Tunneling Current in Heterostructures with Bias Voltage by Considering Spin Polarization Effect

“…It has received great attention in the study of charge transport in heterostructures due to its application in spintronic devices [1][2][3]. Since the invention of diluted magnetic semiconductors (DMS) by Ohno many researchers have reported that spin polarization in semiconductor heterostructures can be achieved by using a ferromagmetic semiconductor material [4][5][6].…”

Epitaxial CuN Films with Highly Tunable Lattice Constant for Lattice‐Matched Magnetic Heterostructures with Enhanced Thermal Stability

“…[1] Nonmagnetic spacer materials sandwiched between ferromagnetic layers in hybrid multilayer nanostructures are of particular importance for enhancing the magnetoresistance, [2][3][4] controlling the resistance-area product (RA), [5][6][7] and even achieving interfacial perpendicular magnetic anisotropy (PMA). [8,9] Currently, the main spacer materials for magnetoresistance devices are MgO for magnetic tunnel junctions [2,3,8,9] and Cu or Ag for current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) devices.…”

Magnetic Multilayer Structures for Spin Torque Nano Oscillator

“…A very small MR ratio was observed at room temperature of ~0.05%, and the MR increased to only ~0.07% at 50 K for the CFA/Cr/CFA structure. As introduced in Chapter 1, the output power of STNO would be proportional to (MR) 2 . Therefore, a small MR ratio will impede its application as a spin-torque oscillator.…”

“…By combining equation (2-3), (2-4), (2)(3)(4)(5) and (2)(3)(4)(5)(6), the TMR ratio can be written as:…”

“…Memory (STT-MRAM) that can surpass mainstream DRAM memories because of its compatibility with conventional CMOS processing and its non-volatile properties [2].…”