Optical Transistor Made From Single Molecule 92
An anonymous reader writes "Researchers from ETH Zurich have recently managed to create an optical transistor from a single molecule in what is yet another important achievement on the road to quantum computing. The molecule itself is about 2 nanometers in size, much smaller than standard transistors, which means that a lot more could be integrated in a single chip. Dr. Hwang, lead author of the academic paper, said, 'Our single-molecule optical transistor generates almost negligible amount of heat. When a single molecule absorbs one photon, there is some probability (quantum yield) that the molecule emits a photon out. The rest of the energy absorbed turns into heat in the matrix. For the case of the specific hydrocarbon molecule that we use, the quantum yield is near 100%. So almost no heat is generated.'"
Re:OK, so clue me in (Score:4, Informative)
either:
a: the photon is released has a longer wavelength and thus less energy.
b: the rate is "nearly" 100%, as in sometimes it absorbs a photon and produces heat.
Re:OK, so clue me in (Score:4, Informative)
If one photon is absorbed and one emitted where does the heat energy come from. The molecule must be absorbing more than one photon, or is it also being "powered" so that the absorbtion can take place?
I think he's saying that the molecule either releases a photon or heat is generated. In this case there is a high probability that for the photon release, so heat generation is rare.
Re:Photonical engineering (Score:4, Informative)
Re:Leakage (Score:5, Informative)
do quantum transistors suffer from leakage? if so, while this is an excellent piece of engineering on it's own, it's pretty useless in practice as any data would just get lost in the fudge.
Well leakage in electronic circuits comes from current flowing through the semiconductor while it is in an "off" state. Quantum photonics doesn't deal with current (or even electricity), so there would not be the same kind of leakage. I'm not aware of a comparable phenomenon specific to quantum states, but I'm just an EE, so some physicist might prove me wrong.
Everything in the article focused on the heat loss, energy efficiency and potential throughput, but no reasons were specifically given as to why this would succeed where Electronic processors have broken down other than 'Photons are beter than Electrons'. How close can these new transistors get before they start contaminating each other's states? Would these not be more suceptable to outside interference (Stray cosmic rays, shining a torch on it?)
Okay, maybe not the shining a torch on it. But if a single molecule transistor is hit by a stray photon, it *will* affect it's state surely. If so are they going to have abour 20 transistors doing the calculations and matching them for discrepencies?
First of all, photons are better than electrons for the reason I gave above, and because all of our long-distance and high data-rate information transmission is already optical. Instead of going from light to silicon and back, sticking with light reduces latency. It also improves efficiency, as the photon's energy is harnessed to perform the switching.
As for interference, if the molecule only responds to photons, shielding it from outside photons is trivial. It's called a box. I also get the impression FTA that the output of the transistor is well controlled, meaning that interference could be minimized or removed completely very easily.
The article raises more questions than it answers. Maybe I just don't know enough about quantum computing, but I'd like the answers all the same.
When has any quick article about a new tech breakthrough given all the answers?
If there's one thing I've learned... (Score:3, Informative)