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The structural, elastic, electronic, and magnetic properties of the CrCoSi, MnCoSi parent half-Heusler (HH) alloys, and their CrMn[Co.sub.2][Si.sub.2] derivative double half-Heusler (DHH) compound are studied, utilizing the augmented plane wave method, which is based on density functional theory and implemented in the WIEN2k code. The stability of HH structure of the CrCoSi and MnCoSi alloys has been checked for their non-magnetic and ferromagnetic phases, leading to that the latter phase of the type I arrangement is the most stable. The CrMn[Co.sub.2][Si.sub.2] DHH alloy, derivative from the found structural and magnetic ground states of CrCoSi and MnCoSi HH alloys, is constructed and investigated. This DDH as well as its CrCoSi parent HH are found to be resistant to deformation and can be classified as ductile materials, whereas the MnCoSi compound is brittle. By the gradient generalized approximation (GGA), the electronic structures of CrCoSi, MnCoSi, and CrMn[Co.sub.2][Si.sub.2]compounds exhibit a metallic behavior in the spin-up channel and a semiconducting behavior in the spin-dn channel, with band gaps (half-metallic gaps) of 0. 851(0.020), 0.852(0.021), and 0.531(0.002) eV, respectively. The half-metallicity of CrMn[Co.sub.2][Si.sub.2] DHH is retained with smaller (larger) band gap (half-metallic gap) of 0.38(0.106) eV than that of GGA, using GGA + U approximation. In addition, the total magnetic moments are found to be 1, 2, and 3 [[mu].sub.B] for CrCoSi, MnCoSi, and CrMn[Co.sub.2][Si.sub.2], respectively. Therefore, these alloys can be good candidates for spinitronic applications due to their half-metallicity. Key words: half-metal, heusler alloys, spin polarization, mechanical stability, FP-LAPW, 1. Introduction Spin-based electronics has grown into a significant field of study that spans a wide range of high spin-polarized materials, used in spintronic devices. It overcomes the limitations of [...]

Author(s): R. Lebrun [sup.1] , A. Ross [sup.1] [sup.2] , S. A. Bender [sup.3] , A. Qaiumzadeh [sup.4] , L. Baldrati [sup.1] , J. Cramer [sup.1] [sup.2] , A. Brataas [...], Spintronics relies on the transport of spins, the intrinsic angular momentum of electrons, as an alternative to the transport of electron charge as in conventional electronics. The long-term goal of spintronics research is to develop spin-based, low-dissipation computing-technology devices. Recently, long-distance transport of a spin current was demonstrated across ferromagnetic insulators.sup.1. However, antiferromagnetically ordered materials, the most common class of magnetic materials, have several crucial advantages over ferromagnetic systems for spintronics applications.sup.2: antiferromagnets have no net magnetic moment, making them stable and impervious to external fields, and can be operated at terahertz-scale frequencies.sup.3. Although the properties of antiferromagnets are desirable for spin transport.sup.4-7, indirect observations of such transport indicate that spin transmission through antiferromagnets is limited to only a few nanometres.sup.8-10. Here we demonstrate long-distance propagation of spin currents through a single crystal of the antiferromagnetic insulator haematite ([alpha]-Fe.sub.2O.sub.3).sup.11, the most common antiferromagnetic iron oxide, by exploiting the spin Hall effect for spin injection. We control the flow of spin current across a haematite-platinum interface--at which spins accumulate, generating the spin current--by tuning the antiferromagnetic resonance frequency using an external magnetic field.sup.12. We find that this simple antiferromagnetic insulator conveys spin information parallel to the antiferromagnetic Néel order over distances of more than tens of micrometres. This mechanism transports spins as efficiently as the most promising complex ferromagnets.sup.1. Our results pave the way to electrically tunable, ultrafast, low-power, antiferromagnetic-insulator-based spin-logic devices.sup.6,13 that operate without magnetic fields at room temperature.Tunable spin transport over long distances is demonstrated through the antiferromagnetic insulator haematite, paving the way to the development of spin-logic devices based on antiferromagnetic insulators.

Author(s): Sasikanth Manipatruni [sup.1] , Dmitri E. Nikonov [sup.1] , Chia-Ching Lin [sup.1] , Tanay A. Gosavi [sup.1] , Huichu Liu [sup.2] , Bhagwati Prasad [sup.3] , Yen-Lin Huang [sup.3] [...], Since the early 1980s, most electronics have relied on the use of complementary metal-oxide-semiconductor (CMOS) transistors. However, the principles of CMOS operation, involving a switchable semiconductor conductance controlled by an insulating gate, have remained largely unchanged, even as transistors are miniaturized to sizes of 10 nanometres. We investigated what dimensionally scalable logic technology beyond CMOS could provide improvements in efficiency and performance for von Neumann architectures and enable growth in emerging computing such as artifical intelligence. Such a computing technology needs to allow progressive miniaturization, reduce switching energy, improve device interconnection and provide a complete logic and memory family. Here we propose a scalable spintronic logic device that operates via spin-orbit transduction (the coupling of an electron's angular momentum with its linear momentum) combined with magnetoelectric switching. The device uses advanced quantum materials, especially correlated oxides and topological states of matter, for collective switching and detection. We describe progress in magnetoelectric switching and spin-orbit detection of state, and show that in comparison with CMOS technology our device has superior switching energy (by a factor of 10 to 30), lower switching voltage (by a factor of 5) and enhanced logic density (by a factor of 5). In addition, its non-volatility enables ultralow standby power, which is critical to modern computing. The properties of our device indicate that the proposed technology could enable the development of multi-generational computing.A scalable spintronic device operating via spin-orbit transduction and magnetoelectric switching and using advanced quantum materials shows non-volatility and improved performance and energy efficiency compared with CMOS devices.

Author(s): Motoi Kimata [sup.1] [sup.2] [sup.5] , Hua Chen [sup.3] [sup.6] , Kouta Kondou [sup.2] [sup.4] , Satoshi Sugimoto [sup.1] [sup.7] , Prasanta K. Muduli [sup.1] , Muhammad Ikhlas [sup.1] [...], The spin Hall effect (SHE).sup.1-5 achieves coupling between charge currents and collective spin dynamics in magnetically ordered systems and is a key element of modern spintronics.sup.6-9. However, previous research has focused mainly on non-magnetic materials, so the magnetic contribution to the SHE is not well understood. Here we show that antiferromagnets have richer spin Hall properties than do non-magnetic materials. We find that in the non-collinear antiferromagnet.sup.10 Mn.sub.3Sn, the SHE has an anomalous sign change when its triangularly ordered moments switch orientation. We observe contributions to the SHE (which we call the magnetic SHE) and the inverse SHE (the magnetic inverse SHE) that are absent in non-magnetic materials and that can be dominant in some magnetic materials, including antiferromagnets. We attribute the dominance of this magnetic mechanism in Mn.sub.3Sn to the momentum-dependent spin splitting that is produced by non-collinear magnetic order. This discovery expands the horizons of antiferromagnet spintronics and spin-charge coupling mechanisms.A magnetic contribution to the spin Hall effect is observed in the non-collinear antiferromagnet Mn.sub.3Sn, which is attributed to momentum-dependent spin splitting produced by non-collinear magnetic order.

Organic semiconductors are studied intensively for applications in electronics and optics (1), and even spin-based information technology, or spintronics (2). Fundamental quantities in spintronics are the population relaxation time ([T.sub.1]) [...]

Author(s): Peter van der Straten [sup.1] Author Affiliations: (1) Peter van der Straten is at the Debye Institute for Nanomaterials Science, Utrecht University, 3508 TA Utrecht, the Netherlands., The spin [...], Ultracold atomic gases are excellent platforms for exploring phenomena in condensed-matter physics. They have now been used to engineer the spin Hall effect and to make the atomic counterpart of the spin transistor. See Letter p.201 Cold-atom spin transistor The spin Hall effect is a phenomenon in which, in the absence of a magnetic field, particles such as electrons experience a Lorentz-like force with a direction depending on each particle's spin. The paper demonstrates the spin Hall effect in a quantum-degenerate Bose gas, realizing an analogue of a semiconductor spin transistor. The results have potential applications for magnetic or inertial sensors, and suggest a way of engineering topological insulators with quantized spin Hall effects in ultracold quantum gases.

Ultracold atomic gases are excellent platforms for exploring phenomena in condensed-matter physics. They have now been used to engineer the spin Hall effect and to make the atomic counterpart of [...]

By harnessing the way charge carriers move in a magnetic field, computing blocks based on semiconductor junctions have been made that are reconfigurable and can be interconnected to perform complex [...]