Hijacking edit : The article in this post is trash look at this one : https://spectrum.ieee.org/thermal-transistor

I'm not sure if I understand this very well, and how small these could be built.

But let's look at the computer cpus. It maybe would allow for a better heat management in these chips.

When a cpu is designed, the engineers have no idea where the hot-spot is. After plenty of testing, a general spot for a termal probe would be found. However that spot may not be the real hot spot, due to limitations in the design and other factors, like the uneven dissipation of heat in the chip. So there is a tollererance used to prevent the chip from burning itself.

Maybe these thermal transistors could transfer the heat where it really matters and even out how the head gets out of the cpu, which would possibly enhance that heat management and get better results.

I don't remember exactly where this cpu temperature probe limitation was discussed. It would be in one of these 2 videos from Der8auer :

https://youtu.be/ljZt_TQegHE?si=gMbcvfkznG-scZh0

https://youtu.be/h9TjJviotnI?si=lzt057vUjGb6YIPa

It's a bit over my head but the gist I'm getting is that you can do more interesting things when you can go from simply predicting the heat dissipation of a component, to controlling that heat dissipation.

While there have been efforts in tuning thermal conductivity, their performances have suffered due to reliance on moving parts, ionic motions, or liquid solution components. This has resulted in slow switching speeds for heat movement on the order of minutes or far slower, creating issues in performance reliability as well as incompatibility with semiconductor manufacturing.

Sadly the study itself is paywalled so I couldn't go too deep into it but reading some other articles and also some other news articles covering this study, the way I understand it is so:

Heat buildup in electronics cause a reduction in performance, and is a direct result of electricity flowing through the electronic circuits. Therefore it is unavoidable (at least until we achieve room temp superconductors - which conduct electricity without causing heat build up).

So far we have relied on passive heat flow to keep electronic circuits under their max operating temperature. For example, a heat sink attached directly to critical locations of heat build up in the circuit. In this example, the heat cant be controlled, it is always flowing into the heat sink.

When the circuit is first activated the heat sink is at room temp and can conduct heat out of the circuit at a high rate. However, the sink has a maximum rate of heat dissipation, so once the sink heats up, the rate of heat flowing out of the circuit and into the sink is decreased, which necessitates a reduction in the circuits performance to decrease it's heat production

Think of it like a kitchen sink. The tap can blast water into the sink at a high rate but the drain cant drain the water at the same rate, so once the sink is full, you have to turn down the flow of water from the tap. The tap is the flow of heat from the circuit into the heat sink, and the drain is the heat dissipating from the heat sink.

Apparently, this new device will form a critical part of a different, more controlled method of heat dissipation.

The way I understand it, you could perhaps have 2 heat sinks with the device directing the flow of heat to only one sink at a time. When the first heat sink reaches critical capacity, instead of reducing the performance of the circuit to reduce heat production, the new device can efficiently and rapidly switch the flow of heat into the second heat sink, which has been inactive up until this point.

The first heat sink no longer has heat flowing into it and can cool down rapidly, while the newly active heat sink can conduct heat out of the circuit at peak performance until it reaches capacity.

At which point, presumably, the new device from the study would switch the heat flow again, back into the first heat sink, which can perform maximally once more as it has theoretically returned to room temp.

To use the kitchen sink analogy, it would be like having two kitchen sinks, and the newly created device allows you to switch the tap to the second sink once the first is full without decreasing the flow out of the tap. The first sink then has time to drain without any further water input while the second sink can handle the full output of the tap.