Cr-Doped Ge-Core/Si-Shell Nanowire: An Antiferromagnetic Semiconductor

Abstract

An antiferromagnet offers many important functionalities such as opportunities for electrical control of magnetic domains, immunity from magnetic perturbations, and fast spin dynamics. Introducing some of these intriguing features of an antiferromagnet into a low dimensional semiconductor core−shell nanowire offers an exciting pathway for its usage in antiferromagnetic semiconductor spintronics. Here, using a quantum mechanical approach, we predict that the Cr-doped Ge-core/Sishell nanowire behaves as an antiferromagnetic semiconductor. The origin of antiferromagnetic spin alignments between Cr is attributed to the superexchange interaction mediated by the p z orbitals of the Ge atoms that are bonded to Cr. A weak spin−orbit interaction was found in this material, suggesting a longer spin coherence length. The spin-dependent quantum transport calculations in the Cr-doped nanowire junction reveals a switching feature with a high ON/OFF current ratio (∼41 times higher for the ON state at a relatively small bias of 0.83 V).

Antiferromagnetic α-MnTe: Molten-Salt-Assisted Chemical Vapor Deposition Growth and Magneto-Transport Properties

“…Antiferromagnetic (AF) materials have stimulated great interest in recent years because of various physical properties including electrical control of magnetism, , strong anomalous Hall effect, , and ultrahigh spin dynamics frequency, , which hold potential for exploiting memory devices, − novel magnetic detectors, , and THz sources. , Compared with ferromagnets, antiferromagnets possess antiparallel microscopic moments and zero net magnetization; , hence, memories based on antiferromagnets would be robust against external magnetic disturbance, achieving high data retention and high-density integration. , In particular, AF semiconductors merging the magnetic order with electrical controlled transport properties of semiconductors have attracted widespread attention for their simultaneous tunability of both charge and spin of carriers. , By taking advantage of electron spins as an information carrier, such as nonvolatile, free of Joule heating, long decoherence time, and direct coupling to photon spins, the AF devices are expected to be faster, more functional, and energy-efficient. ,, …”

“…16,17 In particular, AF semiconductors merging the magnetic order with electrical controlled transport properties of semiconductors have attracted widespread attention for their simultaneously conventional tunability of both charge and spin of carriers. 18,19 By taking advantages of electron spins as information carrier, such as nonvolatile, free of Joule heating, long decoherence time and direct coupling to photon spins, the AF devices are expected to be faster, more functional and energy-efficient. 16,20,21 Manganese telluride (MnTe) is a typical AF semiconductor with a moderate band gap of 1.25-1.46 eV.…”

Chemical exfoliation of 1-dimensional antiferromagnetic nanoribbons from a non-van der Waals material

“…3 Materials such as nanowires and nanoribbons are categorized as 1D and can be used in sensing, 4 catalysis, 5 and filtration. 6 Magnetic nanowires have further uses as nanobarcodes, 7 detectors of biopolymers, 8 spintronic devices, 9,10 data storage, 11 and as model materials for unconventional physics, such as magnetic frustration 12 and curvature-induced changes in magnetic field textures. 13 Given this widespread interest, scalable methods that are applicable to a broad range of 1D structures are needed.…”

PbTe(core)/PbS(shell) Nanowire: Electronic Structure, Thermodynamic Stability, and Mechanical and Optical Properties

“…35 In addition, the transition metal doped core/shell nanowires have been shown to act as an excellent spin filter 36 and a high-performance switching device. 37 Moreover, the core/shell nanostructures have been the subject of considerable interest for catalytic applications. For example, the transition metal dichalcogenide core/shell nanostructures have been shown to enhance the H 2 generation process after interpolating lithium, 38 suggesting that these core/shell nanostructures can act as an efficient electrocatalytic material.…”

“…Furthermore, the reported value of the ON state current in the core/shell semiconductor nanowire field effect transistors (FETs) is found to be 3–4 times higher compared to the state of the art metal oxide semiconductor field effect transistors (MOSFETs), indicating their superior performance; the core/shell semiconductor nanowire FETs also form essential components of the programmable logic circuits . In addition, the transition metal doped core/shell nanowires have been shown to act as an excellent spin filter and a high-performance switching device . Moreover, the core/shell nanostructures have been the subject of considerable interest for catalytic applications.…”