Single-Atom Writer a Landmark for Quantum Computing

Ndickson. Wikipedia Commons
Ndickson. Wikipedia Commons

A research team led by Australian engineers has created the first working quantum bit based on a single atom in silicon, opening the way to ultra-powerful quantum computers of the future.

In a landmark paper published September 19 in the journal Nature, the team describes how it was able to both read and write information using the spin, or magnetic orientation, of an electron bound to a single phosphorus atom embedded in a silicon chip.



"For the first time, we have demonstrated the ability to represent and manipulate data on the spin to form a quantum bit, or 'qubit', the basic unit of data for a quantum computer," says Scientia Professor Andrew Dzurak. "This really is the key advance towards realising a silicon quantum computer based on single atoms."



Dr Andrea Morello and Professor Dzurak from the UNSW School of Electrical Engineering and Telecommunications lead the team. It includes researchers from the University of Melbourne and University College, London.



"This is a remarkable scientific achievement -- governing nature at its most fundamental level -- and has profound implications for quantum computing," says Dzurak.



Dr Morello says that quantum computers promise to solve complex problems that are currently impossible on even the world's largest supercomputers: "These include data-intensive problems, such as cracking modern encryption codes, searching databases, and modelling biological molecules and drugs."



The new finding follows on from a 2010 study also published in Nature, in which the same UNSW group demonstrated the ability to read the state of an electron's spin. Discovering how to write the spin state now completes the two-stage process required to operate a quantum bit.



The new result was achieved by using a microwave field to gain unprecedented control over an electron bound to a single phosphorus atom, which was implanted next to a specially-designed silicon transistor. Professor David Jamieson, of the University of Melbourne's School of Physics, led the team that precisely implanted the phosphorus atom into the silicon device.



 UNSW PhD student Jarryd Pla, the lead author on the paper, says: "We have been able to isolate, measure and control an electron belonging to a single atom, all using a device that was made in a very similar way to everyday silicon computer chips."



As Dr Morello notes: "This is the quantum equivalent of typing a number on your keyboard. This has never been done before in silicon, a material that offers the advantage of being well understood scientifically and more easily adopted by industry. Our technology is fundamentally the same as is already being used in countless everyday electronic devices, and that's a trillion-dollar industry."


The team's next goal is to combine pairs of quantum bits to create a two-qubit logic gate -- the basic processing unit of a quantum computer.

Comments

Silicon is inefficient and outdated.
It should have been replaced by synthetic diamonds back in 1996 which were patented for creation of semiconductors (from synthetic diamonds) along with means of production (yes, back in 1996).

Sigh... imagine what we could accomplish using advanced synthetic materials that we can make in abundance.

Lol... none of the tech you see in circulation today comes even close to what we are really capable of creating (in abundance and with sustainability in mind).

@deksman2
What is the benefit of synthetic diamond over silicon if I may ask?

Well... the most prominent example is in computers.
Synthetic diamonds have a much higher heat threshold (which is 2000 degrees C, as opposed to silicon which would start melting at about 150 degrees C).
Synthetic diamonds also wouldn't really release heat (it actually contains it and not gives it off), ergo you would eliminate the need for active cooling (which is currently used to shuffle heat away from traditional silicon based chips and sucks quite a lot of power in the process).
So basically, think smartphone type scale (smaller even - only no heat being emitted from running intense processes) only orders of magnitude faster, powerful, efficient.

This material also allowed us to create electronics on a much smaller scale compared to silicon, and given its extremely high efficiency ratio, computers would be at minimum 40x more powerful, while consuming 1 tenth of power of current computers/electronics.

The analogy is similar to maglev trains (10x more energy efficient, require minor if any maintenance, and are quite a lot more faster than traditional trains) - and that's with what we knew in 1972.
Now imagine what would superior synthetic materials do for efficiency and across the board in general.

Also... the smaller you go, you basically start blurring lines between the power you get in a desktop, laptop, smartphone, tablet, etc.
We started seeing this in consumer electronics that use silicon... but fact is, we could have been doing it some time ago using synthetic diamonds (paper thin electronics with the power of supercomputers or beyond) - though silicon is hardly excluded from this.

Monetary based economics prompt companies to release minor revisions of existing products once every 12 to 24 months.
This is also in line with Moore's law which is nothing more than an economic prediction that transistor (monetary) cost goes down by half once every 2 years.
However, this law has nothing to do with what could have truly been done.

Think of it like this: instead of releasing revisions every 24 months or so, you would basically see 5 to 10 years of 'revisions' at the very start.

The point of how it would be done in a resource based economy is that we'd be using a given material (for example, synthetic diamonds and graphene) to make what is technologically best possible (in line with our latest/cutting edge scientific knowledge), efficient, durable, with sustainability in mind.

In Capitalism - you basically get the most 'cost effective' (cheapest for a company) thing out, with minor revisions - which often translates to old/outdated technology based on same ineffective materials and means of production.
And... 'competing' products are basically very close to each other in terms of capabilities.
There's also a law in place which prohibits any company from putting out too highly advanced product into the market in order to not gain a monopoly - though, they wouldn't do this either way because they can still milk people/consumers using current processes and inefficient materials because it cheap (cost effective) for the company, and the general population is ill-informed - which is why it takes so LONG for us to see real advancements.

I read up on synthetic diamond, and while I was reading I ran across "carbon is soluble in iron at the high temperatures". Do you think that would pose a problem in it's use in electronics?

Carbon may be soluble... but the process you describe doesn't occur anywhere near as close when melting does with Silicon at 150 degrees C.

This also heavily depends on what type of form that carbon is in. Diamond is a pressurized carbon.

The temperatures we are talking about would have to reach 2000 degrees Celsius (as mentioned in my post) in order for synthetic diamonds to start melting or be affected in general. However, making electronic chips from synthetic diamonds alone would produce operational frequencies and capabilities much higher (by orders of magnitude) than those of silicon, at room temperatures no less.

IBM also demonstrated a working silicon processor at 500GhZ if I'm not mistaken (though they said they can go close to 1ThZ) some time ago at room temperatures (with silicon). Multiply that by factor of (at least) 40 for synthetic diamonds, add extra cores, reduce it down to (or very close to) atom size (which is where Silicon cannot go), you can also jack up the voltage to increase the raw speed while keeping in line with low power demands and still not reach 150 degrees C (now think if you jacked up the temperature of these chips up to operate at say 1500 degrees C while drawing same amount of power as current day laptops... ).

The possibilities are quite vast (and that's just with 'commercialized knowledge' - I'm obviously simplifying here, but there are numerous others methodologies that could be applied to the way computers work [some/a lot of which probably either hadn't even been released for public knowledge], especially applicable by using advanced synthetic materials)

Now add greapehene into the mix (which is even BETTER than diamonds, and its band-gap issue was solved in 2009).

Besides... semiconductors made from synthethic diamonds along with methods of production were patented back in 1996 - which is why I'm saying Silicon is outdated.
I think carbon nanotubes were also envisioned and patented before then - which as we know (and scientists knew back then) are applicable in batteries (which hadn't seen practically any advancement over the past 2 and half decades - and that's being generous). 

You can go to www.google.com/patents
Type in a desired word or sentence and feast your eyes on the dates/years when synthetic diamonds became applicable in electronics.

Hmmm. I agree with you on using synthetic diamonds in electronics. As I read more I found that with certain impurities (other elements besides Carbon used) the diamond changes properties, varying from electrical conductivity among other things.