The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
New concepts of magnetic memory devices are exploiting the movement of data bits by current induced domain wall motion. This concept has been widely explored with rectangular nanowires (NWs) or stripes both theoretically and experimentally [1]. In the case of cylindrical NWs not much progress has been made on the experimental side, despite its promising advantages like the absence of Walker breakdown...
Current-induced spin-orbit torque (SOT) is a very recently discovered phenomenon which provides efficient ways to control and manipulate the magnetization. It allows to use the spin-orbit interaction in the bulk or at the interface of a heavy metal (HM) to inject angular momentum in an adjacent ferromagnet (FM) [1-3]. Even though its origin either from Rashba or spin Hall effects is still under debate,...
Magnetic ring structure has attracted quite a lot of research interest within the recent decades, due to their potential applications in magnetic recording technique [1-3]. However, even in the case of elliptic rings, the chirality of magnetization vortex is difficult to be determined. The introduction of some asymmetries into the geometry is helpful to the precise control of the chirality [2,3]....
Density is one of the major design factors of magnetic random access memory (MRAM). Very recently, a tri-level cell (TLC) structure was proposed to enhance the storage density of MRAM. In this work, we propose a new self-reference sensing scheme for the TLC MRAM cell based on its unique property called state ordering. Simulation results show that compared to conventional design, our proposed self-reference...
Wave transmission media created by a periodically modulated magnetic material are referred to as magnonic crystals [1]. The dynamics of magnonic crystals are described by common concepts of solid state physics, i.e., group velocity, density of states, and band structure. We investigate so-called magnonic vortex crystals created via rectangular arrangements of magnetic vortices. Here we aim at the...
Traditional spin transfer torque MRAM (STT-MRAM) uses one transistor and one MTJ (1T-1MTJ) architecture, where the transistor provides bi-polar currents to switch the magnetization of the free layer of the MTJ. Due to the limitation of the maximum current that is available from a typical transistor, for a MTJ device with required thermal stability and data retention at extreme densities, the size...
Spin torque MRAM offers the possibility of ultrahigh density nonvolatile data storage. However, current devices require excessive current densities to switch the magnetization: this greatly limits commercial implementation. Previous researchers [1]-[2] have experimentally demonstrated that the application of approximately 1V across an MgO thin film allows a neighboring ferromagnet to switch with much...
In 1996, Slonczewki [1] and Berger [2] independently predicted an important effect: spin-transfer torque (STT), which can manipulate magnetization orientation in magnetic multilayer nanostructure. This effect can provide a local magnetization manipulation rather than using a long-rang Oersted field induced by a remote current. Due to STT potential applications in magnetic random access memory (MRAM),...
Miniaturization of the magnetic devices is highly recommended for achieving large areal density up to 1 Tbit/in2 in magnetic data storage. Recently, based on the bit patterned media (BPM) concept, nanomagnets have shown huge prospect in this aspect. For the BPM concept, the nanomag-nets-based logic and memory applications require a deterministic 180° switching of the magnetization, i.e. the nanomagnet...
Several recently appeared applications such as spin-caloritronics, heat-assisted magnetic recording or ultra-fast laser induced magnetization dynamics involve high temperatures. The standard micro-magnetic approach is known to fail there due to the conservation of the magnetization length. Recently proposed micromagnetics based on the Landau-Lifshitz-Bloch (LLB) equation overcomes this limitation...
Nanostructured magnetic dots have been of great interest because of their technological importance in future high-density data storage devices. Deep understanding on the magnetization reversal process of nanoscale magnet is essentially important for such device operation, thus numerous studies have been reported so far for various materials with perpendicular magnetic anisotropy, such as Co/ (Pt and...
Current-induced spin-transfer torque (STT) is a mainstream method of switching the magnetization of free layer of magnetic tunnel junctions (MTJs) [1-2]. However, currently STT-MTJ is suffering from speed and energy bottlenecks caused by two tradeoffs: firstly, since the critical write current (Ic0) is proportional to the thermal stability barrier (Δ), it is difficult to reduce Ic0 without decreasing...
Electrical manipulation of magnetization switching, such as spin-transfer torque (STT) switching, electric-field-assistant magnetization switching, and spin-orbit torque (SOT) switching, has been attracting great attentions due to its applications in low-power-consumption spintronic devices, such as magnetoresistive random access memories (MRAMs) and non-volatile magnetic-logic circuits. Recent investigations...
Spin-transfer torque magnetic random access memory (STT-MRAM) has become a promising candidate for future nonvolatile and universal memory because it features non-volatility, fast access time, almost unlimited programming endurance and zero standby power [1-2]. The magnetic tunneling junction (MTJ) is the fundamental building element of STT-MRAM. An MTJ consists of two ferromagnetic layers (a free...
Intense investigations are carried out on novel magnetic materials systems with perpendicular magnetic anisotropy (PMA), where new spin-orbit effects occur due to structural inversion asymmetry (SIA). So called spin-orbit torques (SOTs), have been observed for the first time in PMA nano-structures with SIA, when an electric current is injected [1-3], leading to ultra-efficient current-induced domain...
Magnetic tunnel junction (MTJ) devices with three-terminal cell structure are promising building blocks for ultralow-power and high-performance memories and integrated circuits due to their high-speed and high-reliability features [1]. The three-terminal devices with spin-orbit torque (SOT) switching were recently proposed and have intensively investigated for a couple of years [2-7]. The SOT devices...
Recently, current-induced spin transfer torque is attracting interest because it affects not only a FM but also an AFM [1, 2]. Furthermore, the critical current for AFM switching is more than 10−2 times smaller than typical value for a FM [1]. Therefore, FM/AFM bilayers containing half-metallic FMs are desirable for studying current-induced magnetization switching and spin torque in AFM materials...
As the size of magnetic elements devices reaches the nanoscale, additional physical effects occur which may lead to future promising technical applications. Two well-known examples of such effects are the TMR and GMR, found in the second half of the last century, and used today in conventional magnetic memories [1, 2].
Dzyaloshinskii-Moriya interaction (DMI) has attracted great interest, for it can form novel chiral spin structures including skyrmions [1], which are demonstrated to exhibit exotic dynamic properties and unconventional transport phenomena. For the realization of new spintronic devices, it is essential to study the influence of DMI on spin structures and spin dynamics in confined structures., The DMI...
Despite intensive efforts on quantum mechanical studies of spin-state phases and solitons in spin chains,[1,2] and studies of magnonic crystals,[3,4] utilizing the reciprocal interactions among the magnetic domains for novel magnetization reversal processes has just recently become noticed. Toggling core reversal of adjacent vortex domains by common excitation by a microwave field,[5] state formation...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.