Uplifting News

not my domain, so i looked the title online (the original article is in nature, and not open access, and currently not in uni, so can not access through uni wifi)

here is a theoretical version establishing physics for this effect - https://arxiv.org/pdf/2505.23083v1

I am also not reading the linked article, as it is too flowery for me.

so here is a tl;dr - if you know seebeck effect, this should be somewhat easy. seebeck effect is a effect where if there is a temperature gradient in a material, electricity can be generated. i will not go on about why that happens, but as a statistical argument, just keep in mind that as things are heated, they jiggle (very specific physics term, definitely not me stupidifying oscillations). if it is a "bond" between two atoms (aptly named atomic bonds), we consider a quantisation (fancy way to put number to how strong the vibration is, there is more to it, but not for now) of these oscillations as phonons. another thing is that in materials, these bond are often arranged in some special manners. for most materials, these arrangements are periodic lattices, (think junglee gym bars or rubik cube or some other periodic arrangement). in these materials, phonons can often transfer in different modes, always trapped by the ends. in some materials, these bonds can form helices, where phonons instead of going in straight line, will travel across the helix. if you know what angular momentum is then great, if not, think something with some "speed" going in circles. in that case it will have some angular momentum along the axis of that circle. coming back to main topic, here we have some phonon going across helix, having some angular momentum. now essentially this motion of phonon can create spin current. this requires us to go into separate tangent, abou what spin is, which is well hard to explain. in most materials, there are 2 types of electrons, and we just name these 2 spins up and down (and it has practically nothing to do with up or down directions). as to why there are only 2, is a really big topic we are not going into. but roughly, it is because of nature of material. in non magnetic materials, they behave same, but in magnetic materials, they do not. in some other words, you can say magnetic materials are magnetic because these 2 spins behave differently in these materials. in normal current, we have electrons going from 1 direction to another (kinda, but that is tangent to tangent, not going there). in spin current, these 2 electrons flow in opposite directions. since both are electrons, there is no charge difference created, a spin potential is created. this tudy showed that in non magnetic materials (tungsten and titanium), you could generate spin currents by "injecting" a angular momentum from quartz crystal phonon. if yo have ever heard of angular momentum conservation, this is a consequence of that, as spin current is a kind of angular momentum.

as to why this could be special, spintronics (the name for using electron spin instead of charge for generating currents and making devices) requires lower power than electronics. one of the problems was that you required special magnetic materials, this is a demonstration without magnetic materials.

in my physics world, this is big (in a scale of 1 to 10, 10 being theory of everything done, 1 being boring desk work - this is 5-7 - very big in spintronics, and reasonably big electronics), but to someone outside -not that big, like for decade(s). we made first transistors in 50s and 60s, an reasnable electronic devices (the semiconductor chips) by 70s and 80s. we made first spin transistors in 00-10s so i guess another 10 or so years before we see some industry level production.