Magnetic field

Astronomers Detect First Signature of Magnetic Field on a Planet Outside of Our Solar System

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Exoplanet HAT-P-11b

Artist’s impression of HAT-P-11b, an exoplanet orbiting its host star at just one-twentieth of the distance from the Earth to the sun.

Researchers have identified the first signature of a magnetic field surrounding a planet outside of our solar system. Earth’s magnetic field acts as a shield against energetic particles from the sun known as the solar wind. Magnetic fields could play similar roles on other planets.

An international team of astronomers used data from the Hubble Space Telescope to discover the signature of a magnetic field in a planet outside our solar system. The finding, described in a paper in the journal Nature Astronomy, marks the first time such a feature has been seen on an exoplanet.

A magnetic field best explains the observations of an extended region of charged carbon particles that surround the planet and stream away from it in a long tail. Magnetic fields play a crucial role in protecting planetary atmospheres, so the ability to detect the magnetic fields of exoplanets is a significant step toward better understanding what these alien worlds may look like.

The team used Hubble to observe the exoplanet HAT-P-11b, a Neptune-sized planet 123 light-years from Earth, pass directly across the face of its host star six times in what is known as a “transit.” The observations were made in the ultraviolet light spectrum, which is just beyond what the human eye can see.

Hubble detected carbon ions – charged particles that interact with magnetic fields – surrounding the planet in what is known as a magnetosphere. A magnetosphere is a region around a celestial object (such as Earth) that is formed by the object’s interaction with the solar wind emitted by its host star.

Charged Carbon Particles Exoplanet HAT-P-11b

Hubble’s observations of an extended region of charged carbon particles that surround the exoplanet HAT-P-11b and streaming away in a long tail are best explained by magnetic field, the first such discovery on a planet outside of our solar system. The planet is depicted as the small circle near the center. Carbon ions fill an immense region it. In the magnetotail, not shown to its full extent, ions escape at the observed average speeds of about 100,000 mph. 1 AU equals the distance between the Earth and the sun. Credit: Lotfi Ben-Jaffel/Institute of Astrophysics, Paris

“This is the first time the signature of an exoplanet’s magnetic field has been directly detected on a planet outside our solar system,” said Gilda Ballester, an adjunct research professor at the University of Arizona Lunar and Planetary Laboratory and one of the paper’s co-authors. “A strong magnetic field on a planet like Earth can protect its atmosphere and surface from direct bombardment of the energetic particles that make up the solar wind. These processes heavily affect the evolution of life on a planet like Earth because the magnetic field shelters organisms from these energetic particles.”

The discovery of HAT-P-11b’s magnetosphere is a significant step toward an improved understanding of the habitability of an exoplanet. Not all planets and moons in our solar system have their own magnetic fields, and the connection between magnetic fields and a planet’s habitability still needs more study, according to the researchers.

“HAT-P-11 b has proven to be a very exciting target, because Hubble’s UV transit observations have revealed a magnetosphere, seen as both an extended ion component around the planet and long tail of escaping ions,” Ballester said, adding that this general method could be used to detect magnetospheres on a variety of exoplanets and to assess their role in potential habitability.

Ballester, a principal investigator of one of the Hubble Space Telescope programs that observed HAT-P-11b, contributed to the selection of this specific target for UV studies. A key discovery was the observation of carbon ions not only in a region surrounding the planet, but also extending in a long tail that streamed away from the planet at average speeds of 100,000 mph. The tail reached into space for at least 1 astronomical unit, the distance between Earth and sun.

Researchers led by the paper’s first author, Lotfi Ben-Jaffel at the Institute of Astrophysics in Paris, then used 3D computer simulations to model interactions between the planet’s uppermost atmospheric regions and magnetic field with the incoming solar wind.

“Just like Earth’s magnetic field and its immediate space environment interact with the impinging solar wind, which consists of charged particles traveling at about 900,000 mph, there are interactions between HAT-P-11b’s magnetic field and its immediate space environment with the solar wind from its host star, and those are very complex,” Ballester explained.

The physics in the magnetospheres of Earth and HAT-P-11b are the same; however, the exoplanet’s close proximity to its star – just one-twentieth of the distance from the Earth to the sun – causes its upper atmosphere to warm and essentially “boil off” into space, resulting in the formation of the magnetotail.

Researchers also found that the metallicity of HAT-P-11b’s atmosphere – the number of chemical elements in an object that are heavier than hydrogen and helium – is lower than expected. In our solar system, the icy gas planets, Neptune and Uranus, are rich in metals but have weak magnetic fields, while the much larger gas planets, Jupiter and Saturn, have low metallicity and strong magnetic fields. HAT-P-11b’s low atmospheric metallicity challenges current models of exoplanet formation, the authors say.

“Although HAT-P-11b’s mass is only 8% of that of Jupiter, we think the exoplanet more resembles a mini-Jupiter than a Neptune,” Ballester said. “The atmospheric composition we see on HAT-P-11b suggests that further work needs to be done to refine current theories of how certain exoplanets form in general.”

Shattering Galactic Beliefs: Astronomers Uncover Surprising Magnetic Field Structures in Milky Way

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Researchers have mapped the magnetic fields in a Milky Way spiral arm, discovering significant variations from previous galactic models. This groundbreaking study, leveraging advanced telescopes and the Gaia satellite, shows that galactic magnetic fields, particularly in the Sagittarius arm, are more complex and influential in star formation than previously thought, offering new insights into the evolution of galaxies.

A team of astronomers including those from the University of Tokyo created the first-ever map of magnetic field structures within a spiral arm of our Milky Way galaxy. Earlier research provided only a broad overview of galactic magnetic fields. However, this novel study uncovers that the magnetic fields within the galaxy’s spiral arms deviate markedly from this broad overview, displaying a significant tilt from the galactic average. These discoveries indicate that magnetic fields have a substantial influence on regions where stars are formed, implying their role in the formation of our solar system.

It might come as a surprise to some that magnetic fields can exist on scales larger than a planet. Most of our daily experience with magnetic fields involves either sticking things to our refrigerator, or perhaps using a compass to point north. The latter shows the existence of magnetic fields generated by our planet. Our sun also creates a vast magnetic field, and this can affect phenomena like solar flares. But magnetic fields that span the galaxy are almost too large to comprehend, and yet they likely have a role in the formation of stars and planets.

New Insights into the Milky Way’s Magnetic Structure

“Until now, all observations of magnetic fields within the Milky Way led to a very limited model that was uniform all over and largely matched the disc shape of the galaxy itself,” said Assistant Professor Yasuo Doi from the Department of Earth Science and Astronomy. “Thanks in part to telescope facilities at Hiroshima University capable of measuring polarized light to help us ascertain magnetic signatures, and the Gaia satellite launched by the European Space Agency in 2013, which specialized in measuring the distances to stars, we are able to build a better model with finer details in three dimensions. We focused on a specific area, the Sagittarius arm of our spiral galaxy (we are in the neighboring Orion arm), and found the dominant magnetic field there breaks away from the plane of the galaxy significantly.”

The white lines superimposed on this image of the Sagittarius arm of the Milky Way show the polarization, or orientation, of light. This correlates with the orientation of local magnetic field lines. Combined, this information builds a detailed map of the magnetic field in that arm of the galaxy. Credit: 2023 Doi et al.

Rethinking Galactic Magnetic Field Models

Previous models and observations could only imagine a smooth and largely homogeneous magnetic field in our galaxy; whereas the new data show that although magnetic field lines in the spiral arms do roughly align with the galaxy at large, at small scales the lines are actually spread out across a range of distances due to various astrophysical phenomena such as supernovae and stellar winds.

The galactic magnetic fields are also incredibly weak, around 100,000 times weaker than Earth’s own magnetic field. Despite this, however, over long time spans, gas and dust in interstellar space are accelerated by these fields which explains the presence of some stellar nurseries — star-forming regions — that cannot be explained by gravity alone. This finding implies further mapping of the magnetic fields within our galaxy could help better explain the nature and evolution of the Milky Way and other galaxies too.

A weak magnetic field saved life on Earth

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The early Solar System was a much different place than it is now.

Chaos reigned supreme before things settled down into their present state.

solar flare

New research shows that the young Sun was more chaotic and expressive than it is now, and that Earth’s magnetic field was key for the development of life on Earth.

Researchers at the Harvard Smithsonian Centre for Astrophysics have been studying a star called Kappa Ceti, about 30 light years away in the Cetus constellation.

Kappa Ceti is in many ways similar to our own Sun, but it’s estimated to be between 400 million to 600 million years old, about the same age as our Sun when life appeared on Earth.

Studying Kappa Ceti gives scientists a good idea of the type of star that early life on Earth had to contend with.

Kappa Ceti, at its young age, is much more magnetically active than our 4.6 billion year old Sun, according to this new research.

It emits a relentless solar wind, which the research team at Harvard says is 50 times as powerful as the solar wind from our Sun.

It’s surface is also much more active and chaotic. Rather than the sunspots that we can see on our Sun, Kappa Ceti displays numerous starspots, the larger brother of the sunspot.

And the starspots on Kappa Ceti are much more numerous than the sunspots observed on the Sun.

We’re familiar with the solar flares that come from the Sun periodically, but in the early life of the Sun, the flares were much more energetic too.

The early Solar System was a much different place than it is now.

Chaos reigned supreme before things settled down into their present state.

New research shows that the young Sun was more chaotic and expressive than it is now, and that Earth’s magnetic field was key for the development of life on Earth.

Researchers at the Harvard Smithsonian Centre for Astrophysics have been studying a star called Kappa Ceti, about 30 light years away in the Cetus constellation.

Kappa Ceti is in many ways similar to our own Sun, but it’s estimated to be between 400 million to 600 million years old, about the same age as our Sun when life appeared on Earth.

Studying Kappa Ceti gives scientists a good idea of the type of star that early life on Earth had to contend with.

Kappa Ceti, at its young age, is much more magnetically active than our 4.6 billion year old Sun, according to this new research.

It emits a relentless solar wind, which the research team at Harvard says is 50 times as powerful as the solar wind from our Sun.

It’s surface is also much more active and chaotic. Rather than the sunspots that we can see on our Sun, Kappa Ceti displays numerous starspots, the larger brother of the sunspot.

And the starspots on Kappa Ceti are much more numerous than the sunspots observed on the Sun.

We’re familiar with the solar flares that come from the Sun periodically, but in the early life of the Sun, the flares were much more energetic too.

NASA Goddard

Researchers have found evidence on Kappa Ceti of what are called super-flares. These monsters are similar to the flares we see today, but can release 10 to 100 million times more energy than the flares we can observe on our Sun today.

So if early life on Earth had to contend with such a noisy neighbor for a Sun, how did it cope? What prevented all that solar output from stripping away Earth’s atmosphere, and killing anything alive? Then, as now, the Earth’s electromagnetic field protected it.

But in the same way that the Sun was so different long ago, so was the Earth’s protective shield. It may have been weaker than it is now.

The researchers found that if the Earth’s magnetic field was indeed weaker, then the magnetosphere may have been only 34% to 48% as large as it is now.

The conclusion of the study says “…the early magnetic interaction between the stellar wind and the young Earth planetary magnetic field may well have prevented the volatile losses from the Earth exosphere and created conditions to support life.”

Or, in plain language: “The early Earth didn’t have as much protection as it does now, but it had enough,” says Do Nascimento.

Evidently.

Researchers have found evidence on Kappa Ceti of what are called super-flares. These monsters are similar to the flares we see today, but can release 10 to 100 million times more energy than the flares we can observe on our Sun today.

So if early life on Earth had to contend with such a noisy neighbor for a Sun, how did it cope? What prevented all that solar output from stripping away Earth’s atmosphere, and killing anything alive? Then, as now, the Earth’s electromagnetic field protected it.

But in the same way that the Sun was so different long ago, so was the Earth’s protective shield. It may have been weaker than it is now.

The researchers found that if the Earth’s magnetic field was indeed weaker, then the magnetosphere may have been only 34% to 48% as large as it is now.

The conclusion of the study says “…the early magnetic interaction between the stellar wind and the young Earth planetary magnetic field may well have prevented the volatile losses from the Earth exosphere and created conditions to support life.”

Or, in plain language: “The early Earth didn’t have as much protection as it does now, but it had enough,” says Do Nascimento.

Evidently.

Magnetic Field May Be a Map for Migratory Birds .

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If you’re lost, you need a map and a compass. The map pinpoints where you are, and the compass orients you in the right direction.Migratory birds, on the other hand, cantraverse entire hemispheres and end up just a couple miles from where they bred last year, using their senses alone. Their compass is the sun, the stars and the Earth’s magnetic field. But their map is a little more mysterious. One theory goes that they use olfactory cues—how a place smells. Another is that they rely on their sense of magnetism.

Researchers in Russia investigated the map issue in a past study by capturing Eurasian reed warblers on the Baltic Sea as they flew northeast towards their breeding grounds near Saint Petersburg. They moved the birds 600 miles east, near Moscow. And the birds just reoriented themselves to the northwest—correctly determining their new position.

Trumpeter swans at the Riverlands Migratory Bird Sanctuary in Illinois. 

Now the same scientists have repeated that experiment—only this time, they didn’t move the birds at all. They just put them in cages that simulated the magnetic field of Moscow, while still allowing the birds to experience the sun, stars and smells of the Baltic. Once again, the birds re-oriented themselves to the northwest—suggesting that the magnetic field alone—regardless of smells or other cues, is enough to alter the birds’ mental map. The study is in the journal Current Biology. [Dmitry Kishkinev et al, Eurasian reed warblers compensate for virtual magnetic displacement]

And if you’re envious of that sixth sense—keep in mind that since the Earth’s magnetic field fluctuates, the researchers say magnetic route-finding is best for crude navigation. Meaning for door-to-door directions—you’re still better off with your GPS.

Stellar discovery: Massive binary star with unique properties

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The first massive binary star, epsilon Lupi, in which both stars have magnetic fields has been discovered by a PhD candidate. A binary star is a star system consisting of two or more stars, orbiting around their common center of mass.
The polarity of the star’s surface magnetic field, north or south, is indicated by red and blue respectively. Yellow lines indicate the magnetic field lines running from the stellar surfaces.

PhD candidate Matt Shultz has discovered the first massive binary star, epsilon Lupi, in which both stars have magnetic fields. A binary star is a star system consisting of two or more stars, orbiting around their common centre of mass.

For the past few years, the BinaMIcS (Binarity and Magnetic Interactions in various classes of Stars) collaboration, formed to study the magnetic properties of close binaries, has been trying to find such an object. They have now discovered one using the Canada-France-Hawaii Telescope.

“The origin of magnetism amongst massive stars is something of a mystery,” says Mr. Shultz (Physics, Engineering Physics and Astronomy), “and this discovery may help to shed some light on the question of why these stars have magnetic fields.”

In cool stars, such as the Sun, magnetic fields are generated by a convection in the outer portion of the star. However, there is no convection in the outer layers of massive star, so there is no support for a magnetic dynamo. Nevertheless, approximately 10 per cent of massive stars have strong magnetic fields.

Two explanations have been proposed for the origin of massive star magnetic fields, both variants on the idea of a so-called “fossil” magnetic field, which is generated at some point in the star’s past and then locked in to the star’s outer portion.

The first hypothesis is that the magnetic field is generated while the star is being formed; the second is that the magnetic field originates in dynamos driven by the violent mixing of stellar plasma when the two stars in a close binary merge.

“This discovery doesn’t change the basic statistics that the BinaMIcS collaboration has assembled,” says Mr. Shultz, “and we still don’t know why there are so few magnetic, massive stars in close binaries.”

The research shows the strengths of the magnetic fields are similar in the two stars, however, their magnetic axes are anti-aligned, with the south pole of one star pointing in approximately the same direction as the north pole of the other.

“We’re not sure why that is yet, but it probably points to something significant about how the stars are interacting with one another. We’ll need to collect more data.”

Magnetic field discovery gives clues to galaxy-formation processes

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Astronomers making a detailed, multi-telescope study of a nearby galaxy have discovered a magnetic field coiled around the galaxy’s main spiral arm. The discovery, they said, helps explain how galactic spiral arms are formed. The same study also shows how gas can be funneled inward toward the galaxy’s center, which possibly hosts a black hole.

“This study helps resolve some major questions about how form and evolve,” said Rainer Beck, of the Max-Planck Institute for Radio Astronomy (MPIfR), in Bonn, Germany.

The scientists studied a galaxy called IC 342, some 10 million light-years from Earth, using the National Science Foundation’s Karl G. Jansky Very Large Array (VLA), and the MPIfR’s 100-meter Effelsberg radio telescope in Germany. Data from both radio telescopes were merged to reveal the magnetic structures of the galaxy.

The surprising result showed a huge, helically-twisted loop coiled around the galaxy’s main spiral arm. Such a feature, never before seen in a galaxy, is strong enough to affect the flow of gas around the .

“Spiral arms can hardly be formed by gravitational forces alone,” Beck said. “This new IC 342 image indicates that magnetic fields also play an important role in forming spiral arms.”

The new observations provided clues to another aspect of the galaxy, a bright central region that may host a black hole and also is prolifically producing new stars. To maintain the high rate of star production requires a steady inflow of gas from the galaxy’s outer regions into its center.

“The magnetic field lines at the inner part of the galaxy point toward the galaxy’s center, and would support an inward flow of gas,” Beck said.

Large-scale Effelsberg radio image of IC 342. Lines indicate orientation of magnetic fields. Credit: R. Beck, MPIfR.

The scientists mapped the galaxy’s magnetic-field structures by measuring the orientation, or polarization, of the radio waves emitted by the galaxy. The orientation of the radio waves is perpendicular to that of the magnetic field. Observations at several wavelengths made it possible to correct for rotation of the waves’ polarization plane caused by their passage through interstellar magnetic fields along the line of sight to Earth.

The Effelsberg telescope, with its wide field of view, showed the full extent of IC 342, which, if not partially obscured to visible-light observing by dust clouds within our own Milky Way Galaxy, would appear as large as the full moon in the sky. The high resolution of the VLA, on the other hand, revealed the finer details of the galaxy. The final image, showing the , was produced by combining five VLA images made with 24 hours of observing time, along with 30 hours of data from Effelsberg.

Scientists from MPIfR, including Beck. were the first to detect polarized radio emission in galaxies, starting with Effelsberg observations of the Andromeda Galaxy in 1978. Another MPIfR scientist, Marita Krause, made the first such detection with the VLA in 1989, with observations that included IC 342, which is the third-closest spiral galaxy to Earth, after the Andromeda Galaxy (M31) and the Triangulum Galaxy (M33).

NASA Discovers Hidden Portals In Earth’s Magnetic Field.

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Our planet has come a long way in scientific breakthroughs and discoveries. Mainstream science is beginning to discover new concepts of reality that have the potential to change our perception about our planet and the extraterrestrial environment that surrounds it forever. Star gates, wormholes, and portals have been the subject of conspiracy theories and theoretical physics for decades, but that is all coming to an end as we continue to grow in our understanding about the true nature of our reality.

 

In physics, a wormhole was a hypothetical feature of space time that would be a shortcut through space-time. We often wonder how extraterrestrials could travel so far and this could be one of many explanations. Although scientists still don’t really understand what they have found, it does open the mind to many possibilities.

NASA Discovers Hidden Portals In Earth’s Magnetic FieldTurning science fiction into science fact seems to happen quite often these days and NASA did it by announcing the discovery of hidden portals in Earth’s magnetic field.

NASA calls them X-points or electron diffusion regions. They are places where the magnetic field of Earth connects to the magnetic field of the Sun, which in turn creates an uninterrupted path leading from our own planet to the sun’s atmosphere which is 93 million miles away.

NASA used its THEMIS spacecraft, as well as a European Cluster probe, to examine this phenomenon. They found that these portals open and close dozens of times each day. It’s funny, because there is a lot of evidence that points toward the sun being a giant star gate for the ‘gods’ to pass back and forth from other dimensions and universes. The portals that NASA has discovered are usually located tens of thousands of kilometres from Earth and most of them are short-lived; others are giant, vast and sustained.

As far as scientists can determine, these portals aid in the transfer of tons of magnetically charged particles that flow from the Sun causing the northern and southerns lights and geomagnetic storms. They aid in the transfer of the magnetic field from the Sun to the Earth. In 2014, the U.S. space agency will launch a new mission called Magnetospheric Multi scale Mission (MMS) which will include four spacecraft that will circle the Earth to locate and then study these portals. They are located where the Earth and the Sun’s magnetic fields connect and where the unexplained portals are formed.

NASA funded the University of Iowa for this study, and they are still unclear as to what these portals are. All they have done is observed charged particles flowing through them that cause electro-magnetic phenomenon in Earth’s atmosphere.

Magnetic portals are invisible, unstable and elusive. they open and close without warming and there are no signposts to guide is in – Dr Scudder, University of Iowa

Mainstream science continues to grow further, but I often get confused between mainstream science, and science that is formed in the black budget world. It seems that information and discovery isn’t information and discovery without the type of ‘proof’ that the human race requires. Given that the human race requires, and has a certain criteria for ‘proof’, which has been taught to us by the academic world, information can easily be suppressed by concealing that ‘proof’.

It’s no secret that the department of defence receives trillions of dollars that go unaccounted for and everything developed within the United States Air Force Space Agency remains classified. They are able to classify information for the sake of ‘national security’. Within the past few years, proof has been emerging for a number of phenomenon that would suggest a whole other scientific world that operates separately from mainstream science.

We have the technology to take ET home, anything you can imagine we already have the technology to do, but these technologies are locked up in black budget projects. It would take an act of God to ever get them out to benefit humanity – Ben Rich, Fmr CEO of LockHeed Skunk Works

– See more at: http://www.thinkinghumanity.com/2013/07/nasa-discovers-hidden-portals-in-earths-magnetic-field.html#sthash.OC80fQgY.Q3YXr2hL.dpuf

Dot Physics The Physics of Wireless Charging

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What if you could charge your phone (or device) without having to worry about the charging cable? Well, you can. This is the idea behind wireless charging. In short, you place your device on some type of pad and then phone gets power without a wire (as long as the phone also supports wireless charging). That’s where they get the term “wireless charging” – you know…because there are no wires.

Magnets and Wires

Let’s start with a very simple demonstration. Here I have a coil of wire connected to a Galvanometer. I could write a whole post on just the Galvanometer, but for now I will just say that it measures electric current. Inside the red coil I am holding a very strong magnet.

Summer 14 Sketches key

If I just hold the magnet inside the coil, nothing happens. However, if I move the magnet either in or out of the coil I get a current.

Wireless

This is all about changing magnetic flux. Yes, just like a “flux capacitor” even though that isn’t a real thing. You can have flux for all sorts of things. My favorite flux to use as an example is rain flux. This is simply the rate that falling rain hits some area – let’s say it’s a sheet of paper.

Summer 14 Sketches key

There are three things you could change that would also change this “rain flux”. First, you could change how much it rains. If the rain comes down faster of course more water will hit the paper (note – real rain drops aren’t shaped like that). Second, you could change the angle between the paper and the rain. Third, you could change the area of paper. That’s rain flux.

We can do the exact same thing with the magnetic field. Guess what we call this? Yes, it’s called the magnetic flux. This magnetic flux depends on the strength of the magnetic field, the angle between the field and the area and the size of the area.

Summer 14 Sketches key

The curved lines are representations of the magnetic field from the magnet.

Here is the physics part. When you change the magnetic flux, you create an electric field inside the wire. This electric field then makes an electric current and electric currents can recharge your phone. Remember, CHANGE in flux is the important part. Actually, you could just use a spinning magnet and a coil of wire and make as much electricity as you want. In fact, this is exactly what happens with a gasoline powered generator. Oh, it’s also how a nuclear power plant makes electricity (the nuclear reactions just turn water to steam and the steam turns a turbine).

Magnetic Flux Without Magnets

The wireless chargers don’t have magnets in them. If you place a wire with current over a magnetic compass you can see that these currents also make magnetic fields.

The Physics of the Railgun Science Blogs Wired

If you replace a moving magnet with a wire that has alternating current, you are all set. The changing electric current in one wire makes a changing magnetic field. This changing magnetic field then induces an electric current in another loop. Also, the more loops you have (in both coils of wires) the greater the effect. Here is simplest version of wireless charging.

mpeg_streamclip_1_9_3b_7_c_2004_2011_squared_5

On the bottom is a huge coil of wire. This wire is then attached to a household style plug. Yes, it’s just a loop of wire with a plug on the end. When you plug this thing into the outlet, electric current runs through the wire. All the outlets in your house have alternating current. This means the current oscillates with a 60 Hz frequency and provides the changing current needed to make a changing magnetic field. On top of this large coil is a smaller coil (in my hand). This coil is just connected to a small lightbulb. When this small lightbulb-coil is near the changing magnetic field, you get an induced current. The current is large enough to light up the lightbulb.

Of course, an actual wireless charger is a little bit smaller – but same idea.

Last question. Previously, I looked at the possibility of charging a smartwatch just by shaking it. Could you power a smartwatch with a wireless charger? Yes, you could. However, the smart watch would have to be right on the charger. It wouldn’t work over a long distance – at least not with this type of wireless charger.

Researchers build first 3D magnetic logic gate.

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The integrated circuits in virtually every computer today are built exclusively from transistors. But as researchers are constantly trying to improve the density of circuits on a chip, they are looking at alternative ways to build circuits. One alternative method uses nano-sized magnets, in which the magnets possess two stable magnetic states that represent the logic states “0” and “1.”

3D magnetic computing 1

Until now, nanomagnetic logic (NML) has been implemented only in two dimensions. Now for the first time, a new study has demonstrated a 3D programmable magnetic logic gate, where the magnets are arranged in a 3D manner. In comparison to the 2D gate, the 3D arrangement of the magnets allows for an increase in the field interaction between neighboring magnets and offers higher integration densities.

The researchers, Irina Eichwald, et al., at the Technical University of Munich in Munich, Germany; and the University of Notre Dame in Notre Dame, Indiana, US, have published their paper on the 3D magnetic logic gate in a recent issue of Nanotechnology.

“We showed for the first time that magnetic field coupling can be exploited in all three dimensions in order to realize magnetic logic computing circuitry, and therefore paves the way for new technologies, where high integration densities combined with low power consumption can be achieved,” Eichwald told Phys.org.

The 3D magnetic logic gate consists of three input magnets that influence the magnetic state of one output magnet. To prepare the output magnet, the researchers used a focused ion beam to irradiate a 40 x 40-nm area of the magnet to destroy its crystalline structure, creating a domain wall. When the magnetic fields from the three input magnets are placed within 100 nm of the irradiated spot, the domain wall’s magnetic state can be controlled. As a result, the output magnet can be switched between the “0” and “1” states.

3D magnetic computing 2
SEM image of the 3D magnetic logic gate. The input magnet I3 is located in a different layer than the rest of the magnets, making the gate three-dimensional. Credit: Eichwald, et al. ©2014 IOP

One important feature of the 3D magnetic logic gate is that one of the input magnets is arranged in an extra layer in comparison to 2D gates. Adding a third dimension enhances the amount of magnetic area surrounding the output magnet by 1/3, and also increases the influence of each input magnet by 1/6. These stronger magnetic effects reduce the error rate and improve the functionality of the gate. The input magnet in the third dimension also programs the gate to operate as either a NOR or NAND gate.

NML has several potential advantages compared to transistors. One is that there is no need for electrical wiring or interconnects because the computation is performed entirely by magnetic interactions between neighboring magnets. NML also operates with , which in turn enables the combination of logic and memory functionality in a single device.

There is also the advantage of high densities using NML, which is possible in part due to the small size of the 3D magnetic gates (here, about 700 x 550 nm). Although high densities lead to the problem of stray magnetic fields interfering with magnets other than their nearest neighbors, the researchers note that previous research has already begun discussing and proposing solutions to these problems. Overall, NML could have a variety of applications.

“The main aspect of 3D nanomagnetic logic is that you can build up circuits, in which a huge number of the computing processes is done simultaneously (the keyword is systolic architecture), while the is kept at a minimum (as you only need to generate a global magnetic field and then you can clock the whole circuitry),” Eichwald said. “Applications are digital filtering, decoding and cryptography. Here all computing processes should be done by magnets.”

The results here pave the way for the development of other 3D architectures of NML circuits in the future.

“The future research plans are to investigate a 3D full adder structure, with the lowest possible number of magnets and the smallest area consumption,” Eichwald said.

MAGNETS MAY ACT AS WIRELESS COOLING AGENTS.

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The magnets cluttering the face of your refrigerator may one day be used as cooling agents, according to a new theory formulated by MIT researchers.

The theory describes the motion of magnons — quasi-particles in magnets that are collective rotations of magnetic moments, or “spins.” In addition to the magnetic moments, magnons also conduct heat; from their equations, the MIT researchers found that when exposed to a magnetic field gradient, magnons may be driven to move from one end of a magnet to another, carrying heat with them and producing a cooling effect.

“You can pump heat from one side to the other, so you can essentially use a magnet as a refrigerator,” says Bolin Liao, a graduate student in MIT’s Department of Mechanical Engineering. “You can envision wireless cooling where you apply a magnetic field to a magnet one or two meters away to, say, cool your laptop.”

In theory, Liao says, such a magnetically driven refrigerator would require no moving parts, unlike conventional iceboxes that pump fluid through a set of pipes to keep things cool.

Liao, along with graduate student Jiawei Zhou and Department of Mechanical Engineering head Gang Chen, have published a paper detailing the magnon cooling theory in Physical Review Letters.

“People now have a new theoretical playground to study how magnons move under coexisting field and temperature gradients,” Liao says. “These equations are pretty fundamental for magnon transport.”

A cool effect

In a ferromagnet, the local magnetic moments can rotate and align in various directions. At a temperature of absolute zero, the local magnetic moments align to produce the strongest possible magnetic force in a magnet. As temperature increases, a magnet becomes weaker as more local magnetic moments spin away from the shared alignment; a magnon population is created with this elevated temperature.

In many ways, magnons are similar to electrons, which can simultaneously carry electrical charge and conduct heat. Electrons move in response to either an electric field or a temperature gradient — a phenomenon known as the thermoelectric effect. In recent years, scientists have investigated this effect for applications such as thermoelectric generators, which can be used to convert heat directly into electricity, or to deliver cooling without any moving parts.

Liao and his colleagues recognized a similar “coupled” phenomenon in magnons, which move in response to two forces: a temperature gradient or a magnetic field. Because magnons behave much like electrons in this aspect, the researchers developed a theory of magnon transport based on a widely established equation for electron transport in thermoelectrics, called the Boltzmann transport equation.

From their derivations, Liao, Zhou, and Chen came up with two new equations to describe magnon transport. With these equations, they predicted a new magnon cooling effect, similar to the thermoelectric cooling effect, in which magnons, when exposed to a magnetic field gradient, may carry heat from one end of a magnet to the other.

Motivating new experiments

Liao used the properties of a common magnetic insulator to model how this magnon cooling effect may work in existing magnetic materials. He collected data for this material from previous literature, and plugged the numbers into the group’s new model. He found that while the effect was small, the material was able to generate a cooling effect in response to a moderate magnetic field gradient. The effect was more pronounced at cryogenic temperatures.

The theoretical results suggest to Chen that a first application for magnon cooling may be for scientists working on projects that require wireless cooling at extremely low temperatures.

“At this stage, potential applications are in cryogenics — for example, cooling infrared detectors,” Chen says.  “However, we need to confirm the effect experimentally and look for better materials. We hope this will motivate new experiments.”

Li Shi, a professor of mechanical engineering at the University of Texas at Austin who was not involved in the research, says the magnetic cooling effect identified by the group is “a highly useful theoretical framework for studying the coupling between spin and heat, and can potentially stimulate ideas of utilizing magnons as a working ‘fluid’ in a solid-state refrigeration system.”

Liao points out that magnons also add to the arsenal of tools for improving existing thermoelectric generators — which, while potentially innovative in their ability to generate electricity from heat, are also relatively inefficient.

“There’s still a long way to go for thermoelectrics to compete with traditional technologies,” Liao says. “Studying the magnetic degree of freedom could potentially help optimize existing systems and improve the thermoelectric efficiency.”

Story Source:

The above story is based on materials provided by Massachusetts Institute of Technology. The original article was written by Jennifer Chu. Note: Materials may be edited for content and length.