Spin-transfer torque (STT) is a phenomenon that occurs in spintronics, a field of electronics that exploits the intrinsic spin of electrons, in addition to their charge, to process and store information. In conventional electronics, information is stored in binary states (0s and 1s) represented by electric charge. In spintronics, the spin state of electrons (up or down) can also be used to represent information.
The Rashba–Edelstein effect refers to a phenomenon observed in spintronic materials, where an electric current can induce a non-equilibrium spin polarization in a system. This effect arises from the interplay between spin-orbit coupling and the flow of charge carriers, typically in two-dimensional electron systems. The Rashba effect, named after physicist Emmanuel Rashba, describes the splitting of electronic states in a system with structural inversion asymmetry due to spin-orbit coupling.
The Rashba effect refers to a phenomenon in condensed matter physics where spin-orbit coupling leads to a splitting of the electronic states in a material with a structure that lacks inversion symmetry. This effect is particularly significant in two-dimensional systems and can have important implications for spintronics, a field of technology that seeks to utilize the intrinsic spin of electrons, in addition to their charge, for information processing.
Racetrack memory (RM) is a type of non-volatile memory technology that leverages the motion of magnetic domain walls in nanostructured magnetic materials to store data. The concept is based on the idea of a "racetrack," where magnetic bits are arranged in a linear fashion and controlled to move along a track, similar to how cars move around a racetrack.
The Rabi problem refers to a fundamental concept in quantum mechanics and quantum optics that describes the oscillatory dynamics of a two-level quantum system (often called a "qubit") interacting with an external oscillatory field, typically a coherent electromagnetic field, like a laser. This interaction leads to what is known as Rabi oscillations, which are coherent oscillations between the two states of the qubit.
The Quantum Spin Hall (QSH) effect is a topological phase of matter characterized by the presence of edge states that conduct electricity without dissipation, while the bulk of the material remains insulating. It is a two-dimensional analogue of the three-dimensional Quantum Hall effect, but it occurs without the necessity of an external magnetic field.
The Quantum Hall Effect (QHE) is a quantum mechanical phenomenon observed in two-dimensional electron systems subjected to low temperatures and strong magnetic fields. It is characterized by the quantization of the Hall conductivity, which is the ratio of the transverse electric field to the longitudinal current density.
Positronium is an exotic atom-like system composed of an electron and its antiparticle, a positron. The electron carries a negative electric charge, while the positron has a positive electric charge. This unique pairing occurs because of the attraction between the two opposite charges, allowing them to bind together.
A Planar Hall sensor is a type of magnetic sensor that is designed to detect the presence and strength of magnetic fields. It operates based on the Hall effect, which occurs when a current-carrying conductor is placed in a magnetic field and experiences a force perpendicular to both the current direction and the magnetic field. This force leads to a voltage difference, known as the Hall voltage, which can be measured.
The Pauli exclusion principle is a fundamental principle in quantum mechanics, formulated by physicist Wolfgang Pauli in 1925. It states that no two fermions (particles with half-integer spin, such as electrons, protons, and neutrons) can occupy the same quantum state within a quantum system simultaneously. In the context of atomic structure, this principle explains why electrons in an atom fill available energy levels in a specific way.
Michael Coey is an Irish physicist known for his work in the field of condensed matter physics and magnetism. His research often involves magnetic materials, spintronics, and the properties of certain types of magnets, including those at the nanoscale. Coey has made significant contributions to the understanding of ferromagnetic and antiferromagnetic materials and is recognized for his academic publications and collaborative work.
Magnetoresistive RAM (MRAM) is a type of non-volatile memory technology that uses magnetic states to represent data. Unlike traditional RAM technologies, such as DRAM or SRAM, which rely on electrical charge or flip-flop circuits, MRAM utilizes magnetic tunnel junctions (MTJs) to store bits of information. Here's a breakdown of its key features and advantages: ### Key Features 1.
Magnetoresistance is a phenomenon in which the electrical resistance of a material changes in the presence of a magnetic field. This effect can be observed in various types of materials, including metals, semiconductors, and insulating materials. ### Key Points about Magnetoresistance: 1. **Basic Principle**: The electrical resistance of materials typically depends on their physical and chemical properties, but when a magnetic field is applied, the movement of charge carriers (such as electrons) within the material can be affected.
Magnetocapacitance refers to the change in capacitance of a material or device when exposed to a magnetic field. This phenomenon can occur in certain materials that exhibit magnetoelectric effects, where their electric and magnetic properties are coupled. In general, capacitance is a measure of a capacitor's ability to store electrical energy in an electric field, and it is influenced by factors such as the area of the conducting plates, the distance between them, and the dielectric material used.
Magneto-electric spin-orbit coupling refers to a phenomenon where the spin and orbital motion of electrons in a material are coupled in the presence of both magnetic and electric fields. This coupling is of significant interest in condensed matter physics and materials science, as it manifests in various ways and can lead to interesting effects and applications, particularly in the fields of spintronics and magnetoelectric materials. ### Key Concepts 1.
A **magnetic semiconductor** is a class of materials that exhibits both semiconductor properties and magnetic order. These materials can carry electric current like conventional semiconductors (such as silicon) and can also exhibit ferromagnetism or antiferromagnetism at certain temperatures, making them useful in a variety of applications that take advantage of both their electronic and magnetic characteristics.
Heusler compounds are a class of intermetallic materials that showcase unique magnetic, electronic, and mechanical properties. They are typically ternary or quaternary alloys composed of three or four elements, frequently featuring combinations of transition metals, main group metals, and sometimes metalloids.
Half-metal is a term used in condensed matter physics and materials science to describe a class of materials that exhibit both metallic and insulating properties depending on the direction of electron spin. In simple terms, half-metals are materials that behave as conductors for one spin orientation (usually called "spin-up") while acting as insulators for the opposite spin orientation (usually called "spin-down").
Giant magnetoresistance (GMR) is a quantum mechanical effect observed in thin films made of alternating layers of ferromagnetic and non-magnetic materials. It manifests as a significant change in electrical resistance in response to an applied magnetic field. The phenomenon was first discovered in the 1980s by Albert Fert and Peter Grünberg, who were awarded the Nobel Prize in Physics in 2007 for their work on GMR.
Flux pumping is a phenomenon that occurs in superconductors and is related to the movement of magnetic flux lines through a superconductor when it is in a state of persistent current. This phenomenon is particularly relevant in the study of type-II superconductors, which allow magnetic flux to penetrate their surface while still maintaining zero electrical resistance. In type-II superconductors, when exposed to an external magnetic field, the material allows magnetic flux to enter in discrete quantized units known as fluxoids or magnetic vortices.