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  • Scientists have now performed an MRI...on a single atom.

  • The world's smallest MRI, how cute is that?!

  • This level of resolution is a breakthrough for the world of microscopy, and has potential

  • applications in all kinds of fields, from quantum computing to drug development.

  • MRI stands for magnetic resonance imaging, and though it may be able to see things inside

  • your body on the more macro scale, this picture is actually the result of tiny shifts in your

  • protons.

  • As the name implies, an MRI scanner creates an extremely strong magnetic field around

  • whatever it's trying to image.

  • This temporarily re-aligns the protons in your body with that magnetic field.

  • Then the machine pulses the sample or the patient with a different current—a radiofrequencywhich

  • pulls the protons slightly out of their alignment with the magnetic field.

  • After the brief radiofrequency pulse is over, the protons snap back into alignment with

  • the field, kind of like a rubber band that's stretched between two fingers snapping back

  • into place after you pull it.

  • The energy that's released as the protons move back into place with the magnetic field

  • is what is detected and visualized by the machine.

  • Different tissues are distinguishable from one another because their protons can take

  • different amounts of time to snap back into place, and release different amounts of energy

  • when they do.

  • But that's on the scale of the human body, full of protons.

  • So, how do you take something like that and apply it to a single atom?

  • If you immediately pictured a tiny, miniature version of an MRI machine, you're not alone,

  • I'm right there with youbut no, that's not how it works.

  • Instead, the researchers who created this technique altered an existing microscopy instrument—a

  • scanning tunneling microscope (STM).

  • STMs involve bringing the tip of the microscope into contact with metal atoms at the surface

  • of a material.

  • The electron cloud of the atoms on the tip of the microscope interact with the electron

  • cloud of the atoms on the surface of the material.

  • When voltage is applied to the tip, those electron clouds become connected by an electric

  • current.

  • Then the electrons of the atoms in the material 'quantum tunnel' to the tip of the microscope,

  • giving you a pretty beautiful picture.

  • This kind of imaging is highly detailed, and at its best gets down to about .1 nanometers,

  • or an angstromwhich is definitely atomic scale.

  • But there's only so much information an image like that contains.

  • Enter: the atomic scale MRI.

  • This joint research team from several institutions around the world applied iron atoms to the

  • tip of a scanning tunneling microscope, generating a magnetic field.

  • Further application of a radiofrequency then induced changes in the spin state of the atoms in

  • the material.

  • The difference in spins between the tip of the microscope and the sample material, gives

  • us a picture of the atom.

  • This means big things in the world of tiny science.

  • The atomic MRI can image atoms on a sub-angstrom level, smaller than ever before.

  • It can tell us about their magnetic properties and spin structures, which you might imagine

  • could be hugely useful in quantum physics...particularly quantum computing.

  • This kind of computing relies heavily on the spin dynamics of particles, and being able

  • to understand and potentially even organize individual atoms with this technology could

  • drive unprecedented advancements in quantum tech.

  • Atomic-scale peeks at magnetic properties of molecules might help us with science on

  • the nanoscale in fields like biology, toothis new technique may help us see how proteins

  • fold, something that could lead to the development of better medicines.

  • And while it's very exciting to think about the possibilities of this new tech, it's

  • not the most easy-to-use apparatus as of yet.

  • The microscopic MRI uses an ultra-high custom vacuum, requires cryogenic temperatures, and

  • has so far only looked at very specific kinds of materials.

  • But the researchers hope to keep developing their tiny MRI to be even simpler to use,

  • continuing to see even more than ever before.

  • If you want even more on exciting developments in microscopy, check out this video over here,

  • and if you have another technology you want us to cover, let us know in the comments below.

  • Make sure you subscribe to Seeker to know when we peer even further down into the details

  • of the universe, and as always, thanks for watching.

  • We'll see you next time.

Scientists have now performed an MRI...on a single atom.

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世界上第一臺單原子核磁共振成像儀問世,它將徹底改變成像技術。 (The World’s First MRI of a SINGLE Atom Is Here, and It Could Revolutionize Imaging)

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    林宜悉 發佈於 2021 年 01 月 14 日
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