Spintronics

Spintronics, short for "spin transport electronics," is a field of research and technology that exploits the intrinsic spin of electrons, as well as their fundamental charge, for information processing and storage. Unlike traditional electronics that primarily rely on the flow of electrical charge, spintronics utilizes the spin state of electrons, which can be thought of as an additional degree of freedom.

Antisymmetric exchange, often referred to in the context of spin interactions in quantum mechanics and condensed matter physics, describes a specific type of interaction between particles with spin, particularly in systems of localized magnetic moments (like in magnetic materials). In quantum mechanics, particles with spin can interact with each other through exchange interactions, which arise from the principles of quantum superposition and the Pauli exclusion principle.

A biexciton is a quantum mechanical state that consists of two excitons. An exciton is a bound state of an electron and a hole (the absence of an electron) in a semiconductor or insulator. When an electron in a semiconductor absorbs energy (such as from a photon), it can be excited from the valence band to the conduction band, leaving behind a hole in the valence band. The electron and hole can then interact through electrostatic attraction, forming an exciton.

Bipolar magnetic semiconductors are a class of materials that exhibit both magnetic properties and semiconductor characteristics. These materials can conduct electricity like traditional semiconductors while also displaying magnetic ordering, which is typically associated with ferromagnetic or antiferromagnetic behavior. The term "bipolar" in this context often refers to the ability of the semiconductor to support both types of charge carriers: electrons (negative charge carriers) and holes (positive charge carriers).

The Center for Quantum Spintronics is a research institution that focuses on the study of quantum phenomena in spintronics, a field of nanotechnology that exploits the intrinsic spin of electrons, along with their fundamental electronic charge, for developing advanced computing and storage devices. At the center, researchers typically explore various aspects of spin-based technologies, including: 1. **Spin Transport:** Investigating how spins can be manipulated and transported in materials.

Colossal magnetoresistance (CMR) refers to a significant change in the electrical resistance of a material in response to an applied magnetic field. This phenomenon is especially pronounced in certain types of manganese oxides, such as perovskite materials. CMR can be defined as an increase in resistance by several orders of magnitude when a magnetic field is applied, compared to the resistance observed in the absence of a magnetic field.

A Cooper pair is a fundamental concept in the theory of superconductivity, which describes the pairing of two electrons (or other fermions) at very low temperatures. Named after the physicist Leon Cooper, who introduced the idea in 1956, Cooper pairs are essential for the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity. In a normal conductor, electrons experience repulsive interactions due to their negative charge.

The Dresselhaus effect refers to a phenomenon observed in certain materials, primarily in the context of spintronics and nanotechnology. It describes the influence of strong spin-orbit coupling on the electronic states in materials with reduced dimensionality, such as quantum wells, nanowires, and other low-dimensional systems. More specifically, the Dresselhaus effect arises from a lack of symmetry in the crystal structure of materials that leads to spin-dependent energy splitting of electronic states.

Electric charge is a fundamental property of matter that causes it to experience a force when placed in an electromagnetic field. It is a scalar quantity and is responsible for electromagnetic phenomena. Electric charge exists in two types: positive and negative. 1. **Types of Charge**: - **Positive Charge**: Carried by protons, which are found in the nucleus of an atom. - **Negative Charge**: Carried by electrons, which orbit the nucleus of an atom.

Electron is an open-source framework that allows developers to build cross-platform desktop applications using web technologies such as HTML, CSS, and JavaScript. It was created by GitHub and is widely used for creating applications that run on Windows, macOS, and Linux. Electron combines Chromium (for rendering the web content) and Node.js (for back-end capabilities) into a single runtime, enabling developers to use web development skills to create feature-rich desktop applications.

Extraordinary magnetoresistance (EMR) is a phenomenon observed in certain materials, particularly in materials that have a complex interplay between their electronic structure and magnetic properties. EMR is characterized by a large change in electrical resistance when exposed to an external magnetic field. This effect is particularly notable in materials with a layered structure, such as certain ferromagnets or half-metals.

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.

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.

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").

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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 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.

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 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.

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.

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 Spin Hall Effect (SHE) is a physical phenomenon observed in certain materials, particularly in solid-state systems, where a transverse spin current is generated in response to an applied electric field. Unlike the conventional Hall effect, which produces a charge current that flows parallel to the applied electric field and results in a transverse voltage due to charge carriers deflecting, the Spin Hall Effect is concerned with the generation of spin polarization rather than charge separation.

Spin Hall magnetoresistance (SMR) is a phenomenon observed in certain magnetic materials and hybrid structures that involve a combination of magnetic and non-magnetic materials. It arises from the interplay between spin currents and charge currents in systems that exhibit the Spin Hall effect and magnetization.

The Spin Nernst Effect (SNE) is a type of spin transport phenomenon that occurs in materials where a temperature gradient induces a spin current. It is a variant of the more general Nernst effect, which describes how a temperature difference can create an electric voltage in a conductor. However, in the case of the Spin Nernst Effect, the focus is on the generation of a flow of spin rather than charge.

Spin canting is a phenomenon observed in magnetic materials, particularly in antiferromagnets, where the spins of magnetic moments deviate from perfect alignment along a particular axis. In an ideal antiferromagnet, adjacent spins are oriented in exactly opposite directions, resulting in no net magnetization.

Spin engineering is a field of research and technology that focuses on the manipulation and control of electron spins in materials. It is closely related to the broader field of spintronics, which is short for spin transport electronics. In spintronics, the intrinsic spin of particles, such as electrons, is utilized alongside their charge for information processing and storage.

A spin gapless semiconductor (SGS) is a type of material that exhibits unique electronic properties, combining characteristics of both semiconductors and magnetic materials. In an SGS, there is no energy gap between the valence band and the conduction band for one of the spin channels (usually the majority spin), while the other spin channel (minority spin) has a significant energy gap.

The spin magnetic moment is a property associated with the intrinsic angular momentum, or "spin," of elementary particles, such as electrons, protons, and neutrons. Spin is a fundamental quantum mechanical property that does not have a direct classical analog; it can be thought of as a form of angular momentum that particles possess even in the absence of any actual motion (i.e., orbiting or rotating). The spin magnetic moment arises due to the particle's intrinsic spin and its associated magnetic properties.

Spin polarization refers to the distribution of electron spins in a material or a system, which can result in a net magnetic moment due to an imbalance in the populations of spin-up and spin-down states. In quantum mechanics, electrons possess an intrinsic angular momentum known as "spin," which can be thought of as a kind of internal magnetic moment. When a material exhibits spin polarization, it means that there is a preference for one of the spin states over the other.

Spin pumping is a phenomenon observed in the field of spintronics, which involves the generation and manipulation of electron spin in materials to create and utilize spin currents. The process typically occurs when a ferromagnetic material is brought into contact with a non-magnetic conductor, such as a metal.

A spin transistor is a type of transistor that harnesses the intrinsic spin of electrons, in addition to their charge, to operate as a switching device. This concept is a part of a broader field known as spintronics (spin electronics), which seeks to exploit the spin degree of freedom of electrons to create new types of electronic devices that can be more efficient and possess greater functionality than traditional charge-based electronics.

A spin valve is a type of device that exploits the phenomenon of spin-dependent electrical resistance, which is related to the spin of electrons. It consists generally of two ferromagnetic layers separated by a non-magnetic metal or semiconductor layer. The key principle behind a spin valve is that the electrical resistance of the device changes depending on the relative magnetization orientations of the two ferromagnetic layers.

Spinplasmonics is an interdisciplinary field that combines aspects of spintronics and plasmonics to manipulate both spin and charge at the nanoscale using light. In more detail: 1. **Plasmonics**: This refers to the study of surface plasmons, which are coherent delocalized electron oscillations that occur at the interface between a metal and dielectric material.

As of my last knowledge update in October 2021, "spinterface" does not refer to a widely recognized term or technology in common usage, including in fields such as computer science, software development, or engineering. It's possible that it could be a niche term, a new technology or concept that has emerged after my last update, or a misspelling or combination of two different terms.

Spin–orbit interaction (or spin–orbit coupling) is a quantum mechanical phenomenon that arises from the interaction between a particle's intrinsic angular momentum (spin) and its orbital motion. In the context of electrons within atoms, it refers to the coupling between the electron's spin and its orbital angular momentum due to the electromagnetic effects that appear from the movement of the electron around the nucleus.

The Stern-Gerlach experiment is a fundamental experiment in quantum mechanics that demonstrates the quantization of angular momentum and the existence of quantum spin. It was first conducted by Otto Stern and Walther Gerlach in 1922. ### Setup: The experiment involves the following components: 1. **Beam of Silver Atoms**: A narrow beam of neutral silver atoms is used. Silver atoms have a single unpaired electron in their outer shell, leading to a net spin and magnetic moment.

Stuart Parkin is a notable physicist and engineer, best known for his contributions to the field of nanotechnology and information storage. He has made significant advancements in magnetic storage technologies, including the development of the concept of spin electronics (or spintronics), which exploits the intrinsic spin of electrons in addition to their charge for storage and information processing.

Superconductivity is a phenomenon where certain materials exhibit zero electrical resistance and expulsion of magnetic fields when cooled below a characteristic critical temperature. This means that once a current is established in a superconducting circuit, it can flow indefinitely without energy loss. ### Key Features of Superconductivity: 1. **Zero Resistance**: When a material transitions into a superconducting state, its electrical resistance drops to zero. This allows for the perfect conduction of electricity.

A superlattice is a periodic structure formed by alternating layers of two or more different materials, typically semiconductors, on a nanometer scale. These layers can be only a few nanometers thick and are engineered to create unique electronic, optical, or mechanical properties that differ from those of the individual materials. The properties of superlattices arise from quantum mechanical effects, specifically when the layer thickness approaches the electron mean free path or the de Broglie wavelength of electrons.

In physics, a "trion" refers to a quasiparticle that consists of three charge carriers, typically two electrons and a "hole," which is a missing electron in a semiconductor. Trions can behave like particles with fractional charges and are often studied in the context of two-dimensional materials, particularly in systems like transition metal dichalcogenides (TMDs).

Tunnel magnetoresistance (TMR) is a quantum mechanical phenomenon observed in magnetic tunnel junctions (MTJs). These junctions consist of two ferromagnetic layers separated by a thin insulating barrier, typically only a few nanometers thick. TMR arises from the spin-dependent tunneling of electrons through this barrier.

The Voigt-Thomson law, also known as Thomson's law, relates to the behavior of materials under deformation, specifically concerning the relationship between stress and strain in the context of plasticity and elasticity. It is primarily associated with the study of materials that exhibit both elastic and plastic deformations.