Electric voltage spin voltage electric current flows. Femtosecond spin current pulses generated by the nonthermal. Here we demonstrate this property using the spin seebeck effect sse, that is, measuring the transverse thermoelectric response to a temperature gradient across a thin film of yttrium iron garnet. Chien1, 1department of physics and astronomy, johns hopkins university, baltimore, maryland 21218, usa 2department of physics, national tsing hua university, hsinchu 300, taiwan 3department of physics and astronomy, university of california, irvine, california 92697, usa. The seebeck effect occurs when a voltage is induced by a temperature difference between the two terminals of a sample.
Femtosecond formation dynamics of the spin seebeck effect revealed by terahertz spectroscopy tom seifert 1,2, samridh jaiswal 3,4, joseph barker 5, sebastian t. It was reported that a spin current perpendicular to an. Length scale of the spin seebeck effect andreas kehlberger,1, ulrike ritzmann,2 denise hinzke,2 erjia guo,1 joel cramer,1 gerhard jakob,1 mehmet c. Intense research was sparked by the discovery of the spin seebeck effect 1416. This effect used in the development of fast and efficient micro switches. Jul 28, 2016 physicists have revealed essential properties of the spin seebeck effect. Pdf broadband optical detection using the spin seebeck effect. With a two temperature model including the local magnon and phonon temperatures the measured spin seebeck. Jul 11, 2012 a giant spin seebeck effectthree orders of magnitude greater than previously detectedhas been observed in a nonmagnetic material, insb.
However, in the year 2008 it was observed that when the heat is applied to a magnetized metal, its electron rearranges according to its spin. Enhanced spin seebeck effect signal due to spinmomentum. Because of the basic importance of quantum spin for physical and chemical processes, spin engineering is relevant for a wide range of scientific and technological applications. From a fundamental standpoint, the spin seebeck effect, like the charge seebeck effect, allows insight into the electronic structure of materials. The seebeck effect is a phenomenon in which a temperature difference between two dissimilar electrical conductors or semiconductors produces a voltage difference between the two substances. In the paramagnet, the spin current is converted into an electric field due to the invserse spin hall effect. Combination of magnetic insulators and conductive films used for measuring sse. Here, a spin voltage is a potential for electron spins to drive a nonequilibrium spin current, 14. From a fundamental standpoint, the spinseebeck effect, like the chargeseebeck effect, allows insight into the electronic structure of materials. The spin seebeck effect sse, the generation of a spin current from a thermal gradient, is a novel effect which involves the interaction between charge, spin and heat. A theoretical description of the magnonic spin seebeck effect was developed by xiao et al. Understand how the effect has been utilized to generate power, build thermal sensors, and some innovative areas of its application the temperature difference conversion between two nonequivalent electrical semiconductors or conductors straight into. These incorporate the material degradation, strength testing, and radiation level from radioactive materials which vary with temperature over the time period. One possible source of pure spin currents is the socalled spin seebeck effect sse in which a thermal gradient.
When two wires composed of dissimilar metals are joined at both ends and one of the ends is heated, there is a continuous current which flows in the thermoelectric circuit. Direct correlation between temperature dependent generation of spin currents and atomic composition of interfaces found. The new technology, known as the spin seebeck effect, has conversion efficiency 10 times higher than the conventional method. The low temperature 280 k and high magnetic field up to 140 koe regime is explored. Here, we utilize the spin seebeck effect sse in pty3fe5o12 devices to detect light from 390 to 2200 nm. A model case is the generation of magnons in magnetic insulators by heating an adjacent metal. A thermocouple measures the difference in potential across a hot and cold end for two dissimilar materials. Pdf giant spin seebeck effect in a nonmagnetic material. Giant spin seebeck effect in a nonmagnetic material nature. Mar 18, 2016 seebeck effect when employed in monitoring the net temperature change in making use of the attained electrical potential can be helpful in determining these parameters as well. Spinseebeck effect in a strongly interacting fermi gas. When a magnon is created or annihilated, an electron flips from majority to minority spinorientation or vice versa to conserve total spin, as illustrated schematically in fig. The seebeck effect is the build up of an electric potential across a temperature gradient. Here we describe a signal in a nonmagnetic semiconductor insb that has the hallmarks of being produced by the spin seebeck effect, but is three orders of.
New spin seebeck thermoelectric device with higher conversion. Their findings contribute to a more thorough understanding of the underlying processes of this effect and thereby support. Insulating magnetic materials, like yttrium iron garnet yig, \yig and nickel ferrite nfo, \nfo, are ideal for the study of this new effect due to avoiding other magnetic. Understanding the transfer of spin angular momentum is essential in modern magnetism research. This chapter presents the most fundamental principles of the spin seebeck effect. The spin seebeck effect, the generation of a spin current by a temperature gradient, has attracted great attention, but the interplay over a millimetre range along a thin ferromagnetic film as well as unintended side effects which hinder an unambiguous detection have evoked controversial discussions. For a given thermal gradient, the electrons in the material separate themselves and generate an electric gradient, in accord with math\delta v s \delta t math where mathsmath is the seebec. Femtosecond spin current pulses generated by the nonthermal spindependent seebeck effect and interacting with. T applied to a ferromagnet is thought to produce a pure spin current detectable by measuring a transverse voltage v t generated by the inverse spin hall effect. New spin seebeck thermoelectric device with higher. The spin seebeck effect in magnetic insulating oxides. Observation of spin seebeck effect and developmenet in new materials, spanish team. Sse from magnontopological surface states interaction.
A model case is the generation of magnons in magnetic insulators by heating an adjacent metal film. The spin seebeck e ect attracted a lot of attention due to possible applications. Giant spin seebeck effect in a nonmagnetic material. Solutionprocessed ferrimagnetic insulator thin film for the.
The spin seebeck effect refers to the generation of a spin voltage caused by a. Seebeck effect definition of seebeck effect by the free. The observed behavior cannot be explained as an interface effect or by variations of the material parameters. Different from the case of devvpr junction, the other three junctions show evident seebeck effect for spindown electrons see fig. Solutionprocessed ferrimagnetic insulator thin film for.
Absence of anomalous nernst effect in spin seebeck effect of. An overview of the achieved inverse spin hall effect voltage vishe is presented to find upper limit of this. The seebeck effect in semiconductors and conductors has been explained clearly to give the reader comprehensive understanding. The seebeck effect is a phenomenon in which a temperature difference between two dissimilar electrical conductors or semiconductors produces a. The creation of an electrical potential across points in a metal that are at different temperatures, caused by the tendency of valence electrons in the. Figure s3 thermoelectric voltage jointly produced by the conventional thermoelectric effect, which causes an upward shift, and the spin seebeck iee, which yields a vieeh loop. Spin seebeck effect spintronics for next generation. In the thermocouple two pieces of metal with different seebeck coefficients, which determine the. The spin seebeck effect sse 11,12,14 is a practical way to generate such a powerful spin wave current. Zt only depends upon the seebeck coefficient if the.
This potential difference is proportional to the temperature difference between the hot and cold ends. First discovered in 1794 by italian scientist alessandro volta, it is named after the baltic. One of the triggers of this research trend is the discovery of the spin seebeck effect sse 7,8,9,10, which refers to the spin current generation in linear response to a temperature gradient. Seebeck effect and seebeck coefficient electrical study app. The spinseebeck effect in a ferromagnetic semiconductor arxiv. Femtosecond spin current pulses generated by the nonthermal spindependent seebeck effect and interacting with ferromagnets in spin valves. The spin seebeck effect is a spinmotive force generated by a temperature gradient in a ferromagnet that can be detected via normal metal contacts through the inverse spin hall effect k. Enhanced spin seebeck effect signal due to spin momentum locked topological surface states zilong jiang, 1 cuizu chang, 2 massoud ramezani masir, 3 chi tang, 1 yadong xu, 1 jagadeesh s. Thermoelectric conversion technology that converts energy abandoned as. When the sample is a ferromagnet or a magnetic multilayer, the seebeck coefficient depends on spin.
Scientists unveil fundamental properties of spin seebeck. Supporting information for thermal spin injection and. Time resolved spin seebeck effect experiments core. Seebeck effect synonyms, seebeck effect pronunciation, seebeck effect translation, english dictionary definition of seebeck effect.
The spin seebeck effect is a spin motive force generated by a temperature gradient in a ferromagnet that can be detected via normal metal contacts through the inverse spin hall effect k. Ppt seebeck effect powerpoint presentation free to. The peltier effect can be considered as the backaction counterpart to the seebeck effect analogous to the backemf in magnetic induction. However, recent work on spindependent transport in thin film.
Spin seebeck mechanical force nature communications. Theory of spin seebeck effect, saitoh group imr, tohoku university, sendai. Seebeck e ect is the spin analogy to the conventional seebeck e ect. Longitudinal spin seebeck effect contribution in transverse. Here, we reveal the initial steps of this spin seebeck effect with spin seebeck effect is of increasing importance in spintronics, since it enables direct generation of a spin current from heat and appears in a variety of magnets ranging from metals and semiconductors to insulators. At present, we understand46 that the spin seebeck effect sse in.
Modern scientists have been able to provide another dimension to the study of seebeck effect by studying the effect of application of heat supply to magnetized electrical conductors. The spin seebeck effect refers to the generation of a spin voltage caused by a temperature gradient in a ferromagnet, which enables the thermal injection of spin. The charge carriers, driven by the thermal gradient, reposition themselves in accordance to their individual spin or angular momentum. When the yig magnetization is in the direction, spinmomentum locking in the ti surface states then leads to a net rate of momentum transfer. Time resolved spin seebeck effect experiments by niklas roschewsky, michael schreier, akashdeep kamra, felix schade, kathrin ganzhorn, sibylle meyer, hans huebl, stephan geprags, rudolf gross and sebastian t. Scientists unveil fundamental properties of spin seebeck effect. Arrows in the figure mark the direction for magnetic sweeping. Jul 28, 2016 scientists unveil fundamental properties of spin seebeck effect by universitaet mainz thermally excited spin waves carry a spin current from the ferromagnet yig in this case into the metal layer. The spin seebeck effect refers to the generation of spin voltage as a result of a temperature gradient. Magnetic contribution to the seebeck effect infoscience epfl.
One potentially useful effect for heat collecting3 is the spin seebeck effect sse4 which was observed in 2008. Stanford libraries official online search tool for books, media, journals, databases, government documents and more. The spin seebeck effect is not only observed in ferromagnetic metal, but also in ferromagnetic semiconductor and. Femtosecond formation dynamics of the spin seebeck effect. Aug 19, 2015 controlling the spin of electrons within a device can produce surprising and substantial changes in its properties. Length scale of the spin seebeck effect uni konstanz. The spin seebeck effect refers to the generation of a spin voltage caused by a temperature gradient in a ferromagnet, which enables the thermal injection of spin currents from the ferromagnet into an attached nonmagnetic metal over a macroscopic scale of several millimeters. For devmnpr, there is a group of spindown seebeck peaks in the vicinity of e f. This rearrangement however not responsible for the creation of heat. Drawing from many cutting edge fields, including physics, materials science, and electronics device technology, spintronics has provided the key concepts for many next generation information processing and transmitting technologies. Apr 25, 2016 the new technology, known as the spin seebeck effect, has conversion efficiency 10 times higher than the conventional method. Spin engineering describes the control and manipulation of quantum spin systems to develop devices and materials. This includes the use of the spin degrees of freedom as a probe for spin based phenomena.
Thermoelectric conversion technology that converts energy abandoned as waste heat back to electric power could potentially save energy and reduce greenhouse gas emissions. This effect has stimulated a strong interest in thermal aspects of spin transport5. The new technology, known as the spin seebeck effect 2, has conversion efficiency 10 times higher than the conventional method 3. Junichiro inoue, in nanomagnetism and spintronics second edition, 2014.
Theory of the spin seebeck effect internet archive. It starts with some basic concepts that are crucial in understanding the spin seebeck effect, including the landau. Gilbert llg phenomenology for describing the magnetization dynamics, the spin. Therefore, a materials seebeck coefficient is crucial to its utility. A simple explanation of seebeck effect with its applications. The spin seebeck effect is of increasing importance in spintronics, since it enables direct generation of a spin current from heat and appears in a variety of magnets ranging from metals and semiconductors to insulators.
Maekawa group asrc, jaea, tokai theory of spin seebeck effect. The spinseebeck effect in a ferromagnetic semiconductor. Thermoelectric generation based on spin seebeck effect in. Owingto the simultaneously strong phononelectron drag and spinorbit coupling in insb, the magnitude of the giant spin seebeck voltage is comparable to the largest known classical thermopower values. It describes the generation of an electromotive force in a paramagnetic metal, attached to a ferromagnet, by a temperature gradient 9,106. Modulation of spin thermoelectric properties in transition. Recent studies on the spin seebeck effect have been. We study the spin seebeck effect in a strongly interacting, twocomponent fermi gas and propose an experiment to measure this effect by relatively displacing. Ppt seebeck effect powerpoint presentation free to view. Here, we reveal the initial steps of this spin seebeck effect with spin seebeck effect, the generation of a spin current by a temperature gradient, has attracted great attention, but the interplay over a millimetre range along a thin ferromagnetic film as well as unintended side effects which hinder an unambiguous detection have evoked controversial discussions. Spintronics for next generation innovative devices wiley. A giant spin seebeck effectthree orders of magnitude greater than previously detectedhas been observed in a nonmagnetic material, insb. We study the spinseebeck effect in a strongly interacting, twocomponent fermi gas and propose an experiment to measure this effect by relatively displacing. Spin seebeck and spin peltier effects spin, charge and energy.
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