Detection of Terahertz Magnetic Resonance Could Revolutionize Electronics (phys.org) 49
fahrbot-bot shares a report from Phys.Org: A team of physicists has discovered an electrical detection method for terahertz electromagnetic waves, which are extremely difficult to detect. The discovery could help miniaturize the detection equipment on microchips and enhance sensitivity. The finding, reported today in Nature, is based on a magnetic resonance phenomenon in anti-ferromagnetic materials. Such materials, also called antiferromagnets, offer unique advantages for ultrafast and spin-based nanoscale device applications.
The researchers, led by physicist Jing Shi of the University of California, Riverside, generated a spin current, an important physical quantity in spintronics, in an antiferromagnet and were able to detect it electrically. To accomplish this feat, they used terahertz radiation to pump up magnetic resonance in chromia to facilitate its detection. [...] In order to generate such magnetic resonance, the team of physicists from UC Riverside and UC Santa Barbara worked with 0.24 terahertz of radiation produced at the Institute for Terahertz Science and Technology's Terahertz Facilities at the Santa Barbara campus. This closely matched the precession frequency of electrons in chromia. The magnetic resonance that followed resulted in the generation of a spin current that the researchers converted into a DC voltage. "We were able to demonstrate that antiferromagnetic resonance can produce an electrical voltage, a spintronic effect that has never been experimentally done before," said Shi, a professor in the Department of Physics and Astronomy.
The researchers, led by physicist Jing Shi of the University of California, Riverside, generated a spin current, an important physical quantity in spintronics, in an antiferromagnet and were able to detect it electrically. To accomplish this feat, they used terahertz radiation to pump up magnetic resonance in chromia to facilitate its detection. [...] In order to generate such magnetic resonance, the team of physicists from UC Riverside and UC Santa Barbara worked with 0.24 terahertz of radiation produced at the Institute for Terahertz Science and Technology's Terahertz Facilities at the Santa Barbara campus. This closely matched the precession frequency of electrons in chromia. The magnetic resonance that followed resulted in the generation of a spin current that the researchers converted into a DC voltage. "We were able to demonstrate that antiferromagnetic resonance can produce an electrical voltage, a spintronic effect that has never been experimentally done before," said Shi, a professor in the Department of Physics and Astronomy.
Re: (Score:1)
Post one about the cars running on water conspiracy and how they just can't get the efficiency up
They're using them in South Africa, the problem isn't efficiency exactly, but it is only under narrow conditions where anybody would want a steam car. I mean, in the right conditions, it is great. But it runs slower as the "fuel" (water vapor pressure in the tank) gets used up. Batteries are vastly superior if you can afford the initial cost, both in efficiency and performance. Unless in a remote location that gets a lot of sun, then maybe a cheap solar collector to generate the pressure is better. Don't ru
Re: (Score:2)
Re: (Score:2)
In most cases what these presentations lack is a concrete scientific explanation behind it. The best thing that someone managed to explain to me was that they used some kind of fancy metal (not disclosed) rods in the water.
Now for someone who hasn't learned about the principles of potato or lemon batteries in school, and that those are 'merely' acting as electrolytes for the metals that you jam into them, might believe that the p
Remarkable (Score:5, Funny)
I didnâ(TM)t think it was possible that I was dumb enough to not even understand any of the summary. But here we are.
Re: (Score:2)
This is the similar to the technology that they use to make those scanners that can see through clothes, the ones they use in police vans and some airports.
They've scaled it down so they can now do engineering at those frequencies from Faraday's Law to Ampere's Law and back.
That means they can build faster computers, and also better object-penetrating radar.
That was the part we understood. (Score:2)
What about *the entire rest*?
Like, what are spin current and what is a chroma? (Score:2)
To be specific.
In any case, ... I'll buy ten!
Re: (Score:2)
Re: (Score:2)
Only the underlying technology, there is still a lot of engineering between here and there. It will probably take them 10 years just to fit it into a backpack.
Re: (Score:2)
I'm torn between laughing at you and just agreeing.
What practical application would this allow for?
Re: (Score:3)
Well, I already said it - communication.
That can be used for measuring instruments that allow new types of scanners with the ability to penetrate materials that we couldn't reliably 'see through' before.
And of course it can theoretically be used to transmit data. That is if they manage to shrink all the elements down from the generation, which must be capable of using a method to en
Re: (Score:3)
Again with the practical applications? How come you weren't around when Einstein was doing Relativity to tell him it won't lead to any practical applications that you could see since you couldn't have foreseen GPS. And those crazy quantum nuts back at the same time. What were they thinking producing all that theory and math for, what, nothing. And Evariste Galois, working on group theory, what a waste that was, eh? Sheesh, those nutjobs in the 1800s screwing around with electricity in their labs when it was
Group theory? (Score:2)
Care to explain? I'm not a mathematician, and would love to see the *real world* significance of this. (Hint: Mathematics applications themselves do not count as "real world", unless them aquiring group theory also improved their real-world significance.)
Also, while I generqlly agree more than disagree, there's always aether theory and string theory and such, which were also dead ends. (Although the deciples of the latter just seem to have ignored that the energy the Higgs boson was detected at, killed all
Re: (Score:2)
They are scientists not inventors or engineers.
We don't live in comic book world where the scientist comes up with these massive inventions.
Scientist study the nature of things, understanding its measurement, its actions, its limits... They follow a processes to help study this nature. Hypothesis, Test, repeat until the tests strongly and reliability meet the hypothesis model. Then you make it a Theory. In which additional tests are done to see if there are any problems with it. If all the tests possible ar
Re: (Score:1)
*ahem*. Quantum foam.
You see.... When we determine that it is impossible to measure all attributes of an object accurately due to physical and logical limits on what "measurement" even is.... that's a fundamental property of the universe, and we call it indeterminacy.
However, when we find that it is impossible to say anything about anything scientifically without first drawing a grid of orthogonal lines on paper (or at the very least in our heads), well that's a dirty l
Re:Remarkable (Score:5, Informative)
There's a simple reason why this field of research was of interest and a quick look into the Wikipedia page for Terahertz radiation [wikipedia.org](frequencies from 0.3 to 3 terahertz) will give you an idea.
That is it essentially. We didn't have anything there so far although we know that we should be able to utilize this given that we can utilize microwaves and infrared already. So we've been missing out on something here in the sciences and engineering disciplines of measuring various things. And while the 0.24 terahertz that they used is technically not terahertz radiation by definition (starts at 0.3 THz with its lower boundary), this could still serve as the first big step we've made towards utilizing these frequencies.
The Wikipedia article also highlights another important thing, seeing how there are some suggestions for using this for radio communication over a distance. Our atmosphere strongly attenuates electromagnetic radiation at these wavelengths. Which makes this technology pretty much useless for communication over larger distances here on Earth.
Re: (Score:1)
GPS is a sophisticated triangulation scheme based on the timed pulses of orbital beacons. Has nothing to do with relativity (except that you have to compensate for time dilation for it to even work). The ancient Egyptians who invented trigonometry, however, had real-world applications for their math.
Re: (Score:3)
Hence I'd say it has a lot to do with both SR and GR.
There are those who believe that if we didn't know about those phenomenon beforehand, that we could have resolved the issues numerically by arriving at the same equations, but I wonder how much longer that would have taken us to accomplish
Re: (Score:2)
"I didnâ(TM)t think it was possible that I was dumb enough to not even understand any of the summary. But here we are"
They are saying the next version of Google class can see through your clothes.
Re: (Score:2)
Re:Remarkable (Score:4, Informative)
So, most of you do not know what is "spintronics", a fairly new magnetic paradigm in electronics fabrication, which will eventually replace most or all of the "conventional memory" chips that we use today, especially 'nor' and 'nand' flash memory, allowing faster and more efficient memory with virtually unlimited reprogramming. 'NOR flash' memory is currently limited to less than one million write cycles, because of HCI (hot carrier injection) which is responsible for allowing creation of non-volatile memory layers, but also destroys the device eventually from the intensive electron radiation ('beta rays') it creates.
The main idea is that all fermions (electrons, protons etc) have a property called 'spin', which allows them to be modelled as tiny magnetic dipoles with spin-up or spin-down polarity. In a default distribution, half are up and the other down. But this polarity can be controlled by an external field, to create "magnetic tunnel junctions" (MTJ), which can be used to re-design more efficiently devices currently using semiconductor P-N junctions etc.
"https://en.wikipedia.org/wiki/Tunnel_magnetoresistance"
https://en.wikipedia.org/wiki/... [wikipedia.org]
"https://en.wikipedia.org/wiki/Spin-transfer_torque"
https://en.wikipedia.org/wiki/... [wikipedia.org]
Re: (Score:2)
Maybe. We've heard the same phrases for Josephson junctions, magnetic bubbles, insert your favorite once-nascent technology here. There is still a big distance between demonstration and practicality.
isn't it just 240Ghz (Score:5, Insightful)
Not to be that guy but .24 Thz is really 240 Ghz, I mean they could have said .0024 Thz for my microwave oven.
I was expecting at least 1.0 Thz from this.
Re: isn't it just 240Ghz (Score:5, Informative)
Re: (Score:3)
Re:isn't it just 240Ghz (Score:5, Funny)
Re: isn't it just 240Ghz (Score:2)
Only their Terahertz Facility does.
Specifically Mr Terahertz on the Terahertz floor's Terahertz desk. But only on Terahertz days in the Chinese year of Terahertz.
Re:isn't it just 240Ghz (Score:4, Insightful)
But still, this is some exciting technology.
Well, at least to me due to my profession, as we're closing that gap between a more classical 'antenna' to detect electromagnetic radiation up to high frequency radio waves and the 'photoelectric effect' in semi-conductors used to detect electromagnetic radiation around the infra-red and visual spectrum.
Re: (Score:2)
It's in the neighbourhood. More than 1 Thz quickly becomes infrared, while .24 Thz still behaves like terahertz radiation rather than microwave.
Re: (Score:2)
Well once we get down to a degree of accuracy we will often switch unity.
1/4 mile vs ~1300 feet.
Re: (Score:1)
Wasn't this the same thing... (Score:1)
Captain we are detecting terahertz radiation (Score:3)
Captain we are detecting terahertz radiation, thanks to nanomaterials
https://www.youtube.com/watch?... [youtube.com]
Re: (Score:2)
Re: (Score:2)
What was the moral of the story that we were trying to tell?
Don't know we ran out of time and needed to get rid of the conflict. Just be sure to never use these particular words again in a future episode which they would solve the problem too soon.
Re: (Score:2)
Re: (Score:2)
This guy [slashdot.org], on the other hand, is just a plain old stick-in-the-mud who isn't fun at all, and needs to lighten up.
What a terrible summary (Score:4, Informative)
Current communication technology uses gigahertz microwaves. "For higher bandwidth, however, the trend is to move toward terahertz microwaves," Shi said. "The generation of terahertz microwaves is not difficult, but their detection is. Our work has now provided a new pathway for terahertz detection on a chip."
Re:What a terrible summary (Score:4, Interesting)
Much more likely is a CCD.
There is not actually much utility in wireless communications technology with lots more bandwidth that also uses lots more power at reduced efficiency. But it makes for a more popular research paper than talking about optical scanners at that frequency, which causes all sorts of dystopic headlines.
The area of communications I would expect to see it would be in high bandwidth isolators, where it will bridge a tiny little gap inside an IC.
Re: (Score:2)
I think it is a case of we don't want a lot of "What real world application of this science" arguments from their academic research.
Because there are too many people many of which who fund science, that think science is engineering and every thing learned needs to go into a new product to sell.
Hello Replicators! (Score:1)
Re: (Score:2)
E=MC^2
Converting Energy to Matter will not cheap. That Darn C^2 really puts a hole into the idea of replicators and transporters.
Of all the things that need explaining in TFS... (Score:2)
... you explain only the one that needn't! (That antiferromagnetic materials are called antiferromagnets.)
More like revolutionize energy (Score:3)