Optical Transistor Made From Single Molecule

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.'"

Comments

Negligible amount of heat...

[TapeCutter]

...is generated by the transitor but the compressor needed to keep it at 1.4 Kelvin will keep your basement nice and warm.

Re:Negligible amount of heat...

[fuzzyfuzzyfungus]

Not at all the thing for mobile applications, and likely a stretch even for mid sized systems. If, though, you had a really big job, it might actually be more, or even substantially more, efficient to keep a very very low power chip extremely cold than keep a very very high power chip modestly cool.

Sounds Awesome

[deemen]

... but can it run Crysis? I'm not much of a physicist, but this sounds like exciting news. I'm not really clear on how a single molecule can have properties similar to a transistor though. Gotta cool it down to 1.4 K though, ouch.

Re:Sounds Awesome

[noundi]

Really? You're not clear on how a single molecule, consisiting of electrons, protons and neutrons, can have properties similar to a transistor, meaning it works as a simple AND operator, but you know what 1.4 K is? Where did you go to school young man?

Re:Sounds Awesome

[Anonymous Coward]

The ice levels will look all too realistic if the cooling liquid escapes.

Re:Sounds Awesome

[Anonymous Coward]

...it runs on Cryosis

Re:Sounds Awesome

[Sir_Lewk]

Don't worry. Something tells me you're not quite the target audiance at this point ;)

Re:Sounds Awesome

[selven]

1.4K? Isn't 1400 degrees enough to melt copper?

Re:Sounds Awesome

[Anonymous Coward]

I know you are all trolling but K doesn't mean kilo as in 1000 but K as in Kelvin which is just like Celsius but starts at absolute zero.
So 1.4K is pretty close to how cold you can actually get in this universe.

Re:Sounds Awesome

[GameMaster]

He, if the K stands for thousands then the number is a unit-less quantity, thus making your snarky comment unintelligible. So, where did you go to school? :-p

Re:Sounds Awesome

[Tubal-Cain]

No, silly. You need to cool it down to 1.4 kilograms. How ones does that, though, I have no idea.

Re:Sounds Awesome

[N Monkey]

No, silly. You need to cool it down to 1.4 kilograms. How ones does that, though, I have no idea.

Simple. Pack it in ice and and then accelerate it to 0.9999*c :-)

Photonical engineering

[iCantSpell]

Does anyone know when this science will be taught in universities?

Re:Photonical engineering

[dwieeb]

Probably when universities start caring about education.

Re:Photonical engineering

[Anonymous Coward]

Never?

Re:Photonical engineering

[iCantSpell]

I'm was actually looking for a more serious response.

I think electronics will be the past in less than 20 years.

Re:Photonical engineering

[fuzzyfuzzyfungus]

Based on These results I'd say "several years ago".

Re:Photonical engineering

[Gat0r30y]

I took a biophotonics course at university. The reason they don't teach this much: its dense, and extremely difficult. While the equations might look pretty in Transmission / Waves class, when you actually get down to the scale of molecules and the like, with all of the complications that entails, it is virtually impossible to make meaningful sense of the mathematical results. The best you can do is a computer simulation, which is occasionally useful, and of course test in the lab.

Re:Photonical engineering

[Bakkster]

Does anyone know when this science will be taught in universities?

My university has a Photonics concentration within the Electrical Engineering degree program.

As for learning this kind of cutting-edge stuff, that would happen in a graduate or post-grad program, just like any field.

Re:Photonical engineering

[castironpigeon]

In other words, either we're reaching the limit of what traditional education can teach to a person in a reasonable amount of time or we're reaching the limit of human comprehension. At least one of the two will need a major overhaul before we'll see molecular transistors and biophotonics reach the level of accessibility and acceptance of, say, amateur electronics. And until that happens we'll only see slow, fringe, theoretical progress like this.

Re:Photonical engineering

[noundi]

I think electronics will be the past in less than 20 years.

I'm very curious to know what you mean by that statement.

Re:Photonical engineering

[Anonymous Coward]

Probably he thinks electronics will be supplanted by photonics.

Re:Photonical engineering

[Anonymous Coward]

and i could really give a shit, but i think he means the president is rolling us back to a pre electronics era.

Re:Photonical engineering

[Anonymous Coward]

Well, do you have a detailed understanding of the equations involved in avalanche breakdown of semiconductors and so on?

But it doesn't matter. You just plug in the appropriate zener diode, or transistor or whatever, that do things in a certain way, that we can understand, but how or why it behaves that way, we don't need to know in order to use it effectively.

Re:Photonical engineering

[MozeeToby]

Education isn't about learning every detail about the job you're going to do about graduation. At least a good education isn't. A good college will give you a strong background in an area you wish to pursue, a strong work ethic, but most importantly, it will teach you how to learn. A modern education's primary goal must be to teach the students how to look up and assimilate information on their own.

When you hit an issue at your job, you don't just run to a more experienced co-worker anymore (which was the standard behavior 20 years ago). You look it up online, you read and learn from what you find, then you make a simple project to test out what you've learned. Beyond the very basics of your profession, those are the skills that matter most because those are the skills that produce results when no one else has the answers.

Re:Photonical engineering

[fuzzyfuzzyfungus]

The chap who designed the "appropriate zener diode, or transistor, or whatever" may well have had to understand avalanche breakdown.

Loads of stuff can be used with relatively limited knowledge, which is great; but that doesn't obviate the need for the knowledge of how they work.

Re:Photonical engineering

[7n7]

You look it up online, you read and learn from what you find, then you make a simple project to test out what you've learned.

It is extremely sad how many "developers" can't do this very thing.

TNT

Re:Photonical engineering

[Anonymous Coward]

Another possibility is that our physical laws and/or mathematical models are not useful enough or are systematically flawed in some manner. For me, a well rounded review of the history, current day, and current theoretical physics leads myself (a skeptical rationalist) to the belief that it is impossible to deny the correctness of the emergent (ie classical, historical) physics and the correctness and/or predictive power of current quantum physics; but the existing theoretical (Standard) model is lacking in very many ways, occasionally severely so. The placeholders (dark ___ ) for physical problems which are currently under investigation are rather contrived compared to the mathematics and experimental results surrounding the big (gravity) and small observational results. On top of that, the proposed solutions for fixing the Planck-scale physics (string, brane, foam, bubble) are so far from sensible as can be imagined (short of just giving up entirely). It seems to me that the many existing and proposed models effectively violate otherwise accepted principles or laws (conservation of energy by vacuum expectation or accelerating inflation, an 'ether' by higgs boson, neutrino flux, et al). The point is, I don't think it's hard to make a case that it could be our knowledge that is stopping us from taking another leap, as opposed to our ability. Also, The two scenarios you provided are almost the same restriction; the first quantitative, the second qualitative).

Re:Photonical engineering

[BlueTooth]

...Yes, specialization marches on as the key to technological advances.

Re:Photonical engineering

[bkpark]

The chap who designed the "appropriate zener diode, or transistor, or whatever" may well have had to understand avalanche breakdown.

Loads of stuff can be used with relatively limited knowledge, which is great; but that doesn't obviate the need for the knowledge of how they work.

On the other hand, there are such things as accidental discoveries. If I remember correctly, for the first few decades that we have been making transistors, no one could explain, from basic physical principles, why they work the way they do.

Nonetheless, people knew how to make them (i.e. how to dope the substrates in a particular way and combine them) and they knew how they would work. Knowing why they work that way was, well, simply not required, even for the people who took out patents on the device.

I believe this is still the way it works in much of chemistry and biology, where the subject matter is too complicated to understand from ground up so the best way to go forward is by trial and error—if you understand your results completely, great; if you don't, that doesn't mean you can't still use what you found out from the trials.

Re:Photonical engineering

[metaforest]

Some how I don't think so.

Many times novel properties of materials are discovered by accident. Far more fundamental discoveries are preceded by, "That's odd..." rather than "Eureka! I found it!"

OK, so clue me in

[Anonymous Coward]

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?

Re:OK, so clue me in

[Nadaka]

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

[SlashDotDotDot]

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:OK, so clue me in

[nedlohs]

Do you know what "there is some probability" means?

Hint, it doesn't mean "always".

Re:OK, so clue me in

[Anonymous Coward]

A higher energy photon is absorbed, a lower energy photon is emitted. The difference in energy is the amount of heat dumped into the matrix.

Re:OK, so clue me in

[Rocketship Underpant]

Heat is an electromagnetic phenomenon, so wouldn't that involve a released photon as well?

Re:OK, so clue me in

[2names]

Not necessarily. I'm sure you've noticed the heat produced when you furiously rub your pecker, but have you ever seen it glow?

Re:OK, so clue me in

[rcamans]

Actually, if the photon released is a different frequency than the one absorbed (lower frequency, less energetic), then the energy difference is transformed into heat (movement energy of the atom). The atom will speed up a little. Or the electrons jump out to a higher energy level.
If the photon released is a higher frequency than the one absorbed, the atom will cool of, slow down, or the electrons will drop into a lower energy state.

Re:OK, so clue me in

[Anonymous Coward]

Why, yes, yes I have. Should I see a doctor...or the six o'clock news?

Re:OK, so clue me in

[Anonymous Coward]

As other posters have stated, the emitted photon is of a longer wavelength than the absorbed photon, so the energy difference does get shunted out as heat. What's important is the quantum yield reported. Quantum yield in regards to fluorescence is merely the ratio of the number of emitted photons over the number of absorbed photons. So if you get one fluorescent photon for every absorbed photon, you get a Q.Y. of 1 or 100%, if 1 for every 2 you get .5 or 50%, etc.

Why having a high quantum yield is important in having negligible heat can be understood by looking at the events that don't result in fluorescence. If a molecule absorbs a photon and doesn't emit a photon then all the energy of the absorbed photon must be transformed into heat. This can be a sizeable sum as anyone who has had to walk barefoot across asphalt on a summer day can attest to. So by having a very high Q.Y. most of the energy of the radiant light is actually re-emitted and not kept by the matrix the molecule is in.

Re:OK, so clue me in

[Dragonslicer]

Heat is an electromagnetic phenomenon, so wouldn't that involve a released photon as well?

No, heat is a form of energy. Electromagnetic radiation is also a form of energy. You can convert energy from one form to the other, such as heating an object by shining light on it, or that same object radiating visible light when it gets hot enough, but they aren't the same phenomenon.

Re:OK, so clue me in

[Anonymous Coward]

I have a luminous penis, you insensitive clod!

Re:OK, so clue me in

[s4ltyd0g]

Find a girlfriend and stop watching porn and eating cheetos (-:

Re:OK, so clue me in

[Anonymous Coward]

not exactly. all objects no matter their temperature emit photons, look up blackbody radiation. Energy is also transferred by lattice vibrations in a material (phonons), which can behave much like photons in regards to screwing up your quantum system.

The good news...

[idontgno]

We've made a quantum optical transistor out of a single molecule!

The bad news is that the single molecule masses about 2.4 tonnes. Yeah, it's a pretty big molecule. And don't scuff it, either. We don't want to brush any carbon atoms off the surface.

Re:The good news...

[fuzzyfuzzyfungus]

http://www.theonion.com/content/news/scientists_create_largest_novelty_atom

Re:The good news...

[Colonel Korn]

We've made a quantum optical transistor out of a single molecule!

The bad news is that the single molecule masses about 2.4 tonnes. Yeah, it's a pretty big molecule. And don't scuff it, either. We don't want to brush any carbon atoms off the surface.

That's quite possible, you know. Bowling balls are single molecules. Almost any macromolecule can be made arbitrarily large with cross linking.

Re:The good news...

[Nadaka]

Bowling Balls are not single molecules. They are constructed with a weighted core surrounded by a polymer resin.

However, pure crystals are technically very large molecules. And they can get very large.

Re:The good news...

[Colonel Korn]

Bowling Balls are not single molecules. They are constructed with a weighted core surrounded by a polymer resin.

However, pure crystals are technically very large molecules. And they can get very large.

Okay, I was thinking of old rubber balls. Still, in more modern balls the resin is a single molecule.

Re:The good news...

[Anonymous Coward]

Just a quick question from a moron...

Does any physicist out there think that it's possible that every atom in the universe is unique? Meaning that if you have two oxygen atoms that have the same number of protons, neutrons, and electrons, could a proton in atom A could have something way, way down deep that's different from a proton in atom B? Like a quark or lepton or whatever? Could this explain some of the "probability" that comes along with quantum mechanics? ...I only minored in physics and have no idea what I'm talking about, just wondering.

Leakage

[Canazza]

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.

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?

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.

Re:Leakage

[Bakkster]

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?

Re:Leakage

[rcamans]

photons do not suffer from the issues of signal loss, signal quality, partial reflections, waveform distortion, EMI/EMC, crosstalk, noise, etc. electrons / holes do. Whole regions of current electronic simulation issues go away.
New ones open up.

Re:Leakage

[Khashishi]

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.

Of course, any meaningful computer will have more than thousands of these transistors, and surrounding every transistor with a box is far from practical. And, consider, once you shrink a box down to nanometer sizes, it will become leaky.

Re:Leakage

[Bakkster]

Well, in this case we're talking about lasers traveling through a crystal and being turned on and off with another laser. Unlike electrons and holes in a semiconductor (which drift and move around, causing leakage current), lasers travel in a straight line until they are made to change direction. The laser paths could even cross without interfering with each other.

The only issue I can imagine is scattering, due to dust (practically non-existent in cleanroom manufacturing of this quality) or the transistor crystal. It isn't mentioned how much light is scattered, but I doubt it would be enough to cause significant noise in, even an open system. Since the control laser seems to be a different frequency and direction from the signal laser, even if there was significant scattering, it would just increase the noise in the data. It would not result in undesired transistor switching

As for small boxes, you misunderstand my point. Photons are just light, so putting an opaque material between transistors reduces leakage light to zero. For the processor as a whole, this means a similar opaque package as all silicon chips are enclosed. Between transistors, it is possible to etch channels in an opaque substrate where the light could travel, no 'boxes' needed.

Re:Leakage

[Anonymous Coward]

What makes you think laser light travels in a straight line? (In fact, all light travels in straight lines ...) I guess since you have only ever seen laser pointers (And "ray" guns in SciFi) you have made a silly assumption. Laser light could just as easily be radiated in an isotropic fashion. (Guess you might need to look up some of my terms :-)

Re:Leakage

[Bakkster]

What makes you think laser light travels in a straight line? (In fact, all light travels in straight lines ...) I guess since you have only ever seen laser pointers (And "ray" guns in SciFi) you have made a silly assumption. Laser light could just as easily be radiated in an isotropic fashion. (Guess you might need to look up some of my terms :-)

Hmm, probably because all current optical data transmission is directional, rather than isotropic. Since an isotropic laser makes no sense for the application, I'm not sure why you bring it up. Maybe to give you an opportunity to be condescending as an Anonymous Coward?

Perhaps it's you that made the silly assumption that an Electrical Engineer doesn't know what 'isotropic' means. ;-)

Glowing processors!

[Peteskiplayer]

So does that mean we'll finally get Tron-esque glowing computer parts?! ..I'm guessing it depends on the energy level of the photons and the frequency they are released.. but please let them be a soothing blue :) In all seriousness, this sounds excellent, good job guys.

Re:Glowing processors!

[peragrin]

Well glowy computer parts are cool but I would rather have an optical router and network cards. Fiber to the home.

Re:Glowing processors!

[ae1294]

Fiber to the home

You'll get your fiber to your home in a few years but your internet speed will still be locked at 10/10Mbps. The rest of the bandwidth will be used for pay-per-view and other services as deemed by your local monopoly. O and you'll still be using ipv4 because it would cost a little money upgrade to 6 and they wouldn't want you to have more than 1 IP anyhow, at least not without spending $400 on a business account. O and No static addresses ether... And port 80 among others will still be filtered. It's all for your protection citizen...

Re:Glowing processors!

[motherpusbucket]

Yes! Wham-O is already working on a glowing frisbee using these.

Re:Glowing processors!

[TheThiefMaster]

10/10Mbps?
10/0.5Mbps surely...

Re:Glowing processors!

[DNS-and-BIND]

As long as they pass a law banning the posession of these devices by anyone over 200 lbs. Ugh.

Re:Glowing processors!

[popeye44]

Yea, good luck with the fiber to the home. I have a nice fiber right up to my cabinet on the side of my house.. no one in town will use it. ATT Uverse still wants to use copper. Idiots. Of course Verizon can't come in because it's an ATT area. Frankly Competition sucks for FTTH. So I'm stuck with cable.. which isn't too bad I guess "16/2" but they could do more over the fiber. They don't have any plans either.

Now as far as Quantum Computing goes.. I know about enough to fill a molecule with room for a large Winnebago to fit beside me.

Re:Glowing processors!

[N1ck0]

The down side is if the photon emitted by the molecule is visible to you, it couldn't have be properly passed to the next optical transistor....

okay it could but:
1. you would have to be entangled
2. make sure noone observes you seeing the photon
3. Don't make any sort of measurement or acknowledge that you saw the photon

Otherwise you could either see the light from the processor or the processor would work properly...it couldn't do both. :)

Re:Glowing processors!

[Zakabog]

I had fiber (FiOS) at my home three years ago, port 80 was the only port blocked to my house and I had 40/10Mbps. When I switched to business (since I actually was attempting to run a hosting business out of my home and needed the 5 static IP addresses) it was only an extra $80 a month plus I increased my speed to 50/20Mbps. It was reliable, very fast, and cheap for the bandwidth provided compared to the other options (cable was something like 5/0.5Mbps for the same price as 40/10Mbps FiOS and DSL was even worse.)

Re:Glowing processors!

[Hurricane78]

Nah. WiMAX routers will be at $100 a piece, reaching over 20 miles, and you will have a network with all the other WiMAX routers, giving you a failsafe, multirouting, and encrypted (to the server) connection for "free" (except for the power and the router itself).
Maybe some will offer a city backbone, to reduce the hops to the next major CIX node.

Re:Glowing processors!

[chogori]

I think for that pleasing blue glow it's important that we transmit the photons faster than the speed of light in the transmission medium so that they blue shift.

Kind of like that great blue hue you get on an out-of-control nuclear reactor when atomic particles are hitting the coolant at speeds faster than the speed of light in water.

Re:Glowing processors!

[TheRaven64]

The down side is if the photon emitted by the molecule is visible to you, it couldn't have be properly passed to the next optical transistor....

True, but not always a problem. Consider an AND gate. Ideally, this would emit a photon when it absorbs two photons, and not emit a photon when it absorbs a single photon. In both of these cases, it is absorbing one more photon than it is emitting. This will cause it to get warm. Alternatively, it could emit the spare photon directly upwards away from the die. In this case, you would see the chip flickering quickly.

Of course, this doesn't apply to all gates.

you could call it vaporware

[circletimessquare]

but only because some of the photon bombardment results in actual vaporization of the technology in question

so we need a new word, in regards to nanotech, for the traditional connotation of vaporware meaning technology that is announced but will not be realized. something that has nanotech connotations

hmmm. perhaps sevenofnineware. because you most certainly are out of that league

Re:you could call it vaporware

[maxume]

Fantasyware seems like a good enough name for unrealized nanotech. The confusion that would arise with the realization of some nanotech would be a side benefit.

Mass production?

[gmuslera]

Going a bit further in time with this kind of molecules, how them can be used in mass production of quantum computers, if there will be any of such in the future? Genetic engineering?

The Law of Accelerating Returns,

[Cult of Creativity]

This just blows my mind away, the leaps and bounds that can be made with just a few of these emergent techs is, is.... WOW! While I have never been one completely on the tail of Kurzweils futurism visions of the singularity, this is one step closer to that vision, right? I mean, seems to me that the power of computing with this technology will help us approach that figure where the interconnecting happening within our CPU cycles gets near the same 'mass' as whatever it is that happens in our grey matter between our ears as a species. What was it, something like 10 Teracycles?

Full article in Nature

[Ominus]

http://dx.doi.org/10.1038/nature08134
Couldn't find anything in TFA or at ETH's website. Luckily, it was in a journal who's RSS feed I subscribe to!

Re:Full article in Nature

[Anonymous Coward]

Couldn't find anything in TFA or at ETH's website. Luckily, it was in a journal who's RSS feed I subscribe to!

Here you go: ETH Life article with the link you provided

"Alien Technology"

[erroneus]

Hehehe... this incredible stuff gets me thinking about theories related to Area-51 and technologies from crashed extra-terrestrial alien spacecraft and stuff. Go back in your mind as few as 25 years ago (if you are old enough) and imagine how you would have reacted if such technologies emerged at that time "out of the blue."? I think the reaction would be quite startling. Hell, even 25 years ago there were some pretty amazing developments and the like. But this is pretty awesome stuff. I'm still waiting on some of those materials that are so smooth that it offers no friction to the touch. (I recall some alien encounter thing on TV long long ago where some guy said he touched an alien spacecraft and it was so smooth that he was unsure he was actually touching it because while solid, it offered no friction and at the same time was not wet or oily... to me it sounded like the ultimate in drag reduction technology.)

Re:"Alien Technology"

[TheRaven64]

Not sure about 25 years ago. The first I saw about optical processing was 15 years ago, and this was in the mainstream press so research had been going on for a while. The advantages of optical processing are obvious once you design a nontrivial electronic circuit; photons can pass through each other without interacting, so you don't need to make sure the wires never cross, while electrons can't. Getting photonic circuit elements down to a single molecule is very difficult to do, but not difficult to imagine. It's been fairly obvious since the '60s that these components get will smaller over time and the size of a single molecule is about as small as we can consider making things without a big breakthrough; nanotech is much easier to imagine than femtotech.

Re:"Alien Technology"

[erroneus]

Yeah but this thing with using molecules rather than larger bits of material scaled down and all that? Pretty impressive.

Leaping?

[furby076]

But will i be able theorize that one could time travel within their own lifetime, so I can step into the Quantum Leap accelerator and vanish?

If there's one thing I've learned...

[camperdave]

If there's one thing I've learned from watching Doctor Who, it's that crossing one's own timeline is dangerous and forbidden, except for cheap tricks like undoing your necktie at some one.

What's the gain?

[Anonymous Coward]

I don't see how a transistor that outputs one photon after it absorbs one photon can provide any amplification. Shouldn't it have to output more than one photon in order to provide useful gain?

Re:What's the gain?

[Khashishi]

It's a transistor, not an amplifier.

Re:What's the gain?

[Anonymous Coward]

In every course I have taken in EE, amplifiers are made from transistors because transistors can produce gain.

A transistor without gain... isn't that just a resistor?

I mean the term transistor is short for trans-resistor, which means that you can modulate the resistance with a signal (thus producing a signal gain), so this means that sometimes the transistor will be conducting and others it will be resisting.

So in the light transistor, would the signal be one light source and the power be another light source, would the transistor then switch between transmitting and reflecting, because switching between transmitting and absorbing would defeat everything they said about not heating? Would reflecting the light back even prevent the heating as that light would need to go somewhere?

300x smaller than the wavelength?

[Peter Cooper]

I'm probably being dense here, but I'd really appreciate anyone who can explain how this can possibly work given that the wavelength of light is many hundreds of times longer than 2nm? I read the article and was none the wiser. Given the mention of quantum mechanics, is this related to wave/particle duality? That is, this detects the light particle irrelevant of the wavelength?

Re:300x smaller than the wavelength?

[sFurbo]

The thing about the wavelength is that light can't differentiate anything smaller than the wavelength (or half the wavelength, i can't recall), but it can interact with something smaller. So, if two of these were closer than the wavelength, you can't selectively shine light on one, but you can hit both. Actually, that might be a feature, if you send in one photon, and activate one of two which are closer than the wavelength, their activation will be entangled. But I have no idea whether they plan to use that.

Dude, you missed his point.

[Anonymous Coward]

He isn't talking about jobs, he's talking about individuals messing around. What the GP basically said:

(1) Either this is too hard to teach, or its just plain too hard for most humans to comprehend regardless of how well we teach it, and

(2) Until we fix that situation somehow (such as by enhancing our own brains with technological implants, or whatever) you are not going to see "amateurs" (people) just doing this stuff in their basements as a hobby, which (if it happened) would kick-start all sorts of innovation and breakthroughs.

I'm not sure that making it accessible enough for amateurs to fool around with it in the basement is a necessary condition for the breakthroughs to start coming, but it would surely be sufficient.

Obligatory question

[mcmire]

Does it run Linux?