New way to read data in antiferromagnets unlocks their use as computer memory | Hacker News Reader

New way to read data in antiferromagnets unlocks their use as computer memory

phys.org

38 pointslnyan28 comments

"The discovery suggests that wireless energy, like that from Wi-Fi and mobile signals, could cause antiferromagnets to produce electricity that might one day be tapped to power portable electronic devices."

I think this is even a more interesting application.

Rectennas can do this, it's the basis of passive RFID, but under normal circumstances there's very little power available to harvest.

> unlocks their use as computer memory

The big asterisk on that being "at 5 Kelvin".

They do say next research step is room temperature..

Sure it is. (Memory doesn’t run at room temperature. It runs at half the boiling point of water).

Memory runs at -68.5°C ?

You have water at -68.5 C? Most of us call that ice. So I am pretty sure you know what I mean and you’re flirting with the HN rules.

You can't halve the temperature of something by halving its measument in Celcius, because the celcius starts at some arbitary point above absolute zero.

50 degrees celcius is 86% as hot as the boiling point of water, not 50%.

Needless pedanticism.

You both did the math in kelvin then converted to C. You knew what you were doing.

5 kelvin: the “in mice” of physics.

Now that you mention it, aren't there superconductors that work at only liquid nitrogen temperatures?

There are but they are ceramic which limits their applications because of poor mechanical properties.

The good ones work at liquid nitrogen temperatures. One of the previous times superconductors were the rage there were articles about a new one discovered, that only worked at 8°K or some such.

This feels like one of those things you'll read about every 10 years for your entire life and will always be just 3-5 years away

I think I left my memristors in my flying car.

Does your car run on nuclear fusion power?

It runs on 10x better batteries that are also 10x lighter and charge 10x faster

So, gasoline?

Tsk, no, flow batteries duh.

Just grab a jetpack a go for it!

At least jetpacks are a viable thing now [1][2]... although it shudders to read that these beasts have almost 800 kW of power. The heat from these must be insane.

[1] https://en.wikipedia.org/wiki/Daedalus_Flight_Pack

[2] https://en.wikipedia.org/wiki/Flyboard_Air

https://m.xkcd.com/678/

If you just keep your server room at 5 kelvin, you can continuously take advantage of all the latest science has to offer.

3D Xpoint was shut down by Intel even though the product was promising.

The problem in the volatile and nonvolatile memory market is that a new type of memory will not reach the economies of scale necessary unless it can completely replace the exiting technology.

HBM is still a niche technology.

Processing in memory? Cool but upmem hasn't updated their hardware in a while, indicating that the demand isn't there.

Can any physicist explain the term "quantum metric"?

Googling it appears to give no relevant results. Might it be a typo?

  > "The researchers said that the unique voltage arises from the electronic properties of the manganese bismuth telluride crystals, called the quantum metric."

Sometimes there are properties in quantum systems that are measurable not because of the state itself, but because of the history of the system, for e.g. the topology that an electron travels through. A good example of this is the quantum Hall effect, where you get discrete jumps in the conductance across 2D systems in which a voltage is applied in a transverse direction. This is caused by Berry Curvature, which is the real part of a geometric tensor that describes the topology of the quantum state. The imaginary part of the same tensor is called the “quantum metric”.

In this specific case, they’re measuring a different voltage due to electrons passing through the data written in the antiferromagnet. They pose theoretically in the paper that it could be because of an effect of the quantum metric

Thank you!

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