'Superfast' computers come closer to reality with 'fastest-ever' quantum switch

As per a new study, superfast computers are a step closer to reality as a silicon chip's quantum capabilities have been improved.

The University of Surrey team demonstrated a quantum on/off switching time of about a millionth of a millionth of a second, the fastest-ever quantum switch to be achieved with silicon and over a thousand times faster than previous attempts.

Researcher Ellis Bowyer said that quantum computing exploits the fact that, according to quantum mechanics atoms can exist in two states at once, being both excited and unexcited at the same time. This is known as a superposition state, and is most famously illustrated by Schrodinger's quantum cat which is simultaneously dead and alive.

He added that this superposition of orbital states is very delicate, but they discovered that silicon provides an amazingly clean environment for the phosphorus atoms trapped inside where our quantum information is being stored.

Researchers put the atoms into a superposition state with a very short (a few trillionths of seconds) laser pulse from the FELIX laser facility, and then, they showed they can create a new superposition which depends on the exact time at which a second laser pulse arrives. They found that the superposition state even survives when electrons are flying around the trapped atom while current was flowing through the chip, and even more strangely, the current itself depends on the superposition state.

Quantum superpositions and the resulting quantum technologies are only just beginning to make an impact, but the researchers believe that with new advances in silicon, it is only a matter of time before it becomes more part of the everyday. This work brings that time closer by showing that exotic quantum features, more usually demonstrated with unimaginably tiny things in university physics labs can also be seen using an ordinary voltmeter, said Thornton Greenland of UCL.

Greenland added that what is exciting is that they can see these exotic quantum phenomena in that most common material, silicon, using a measurement as simple as that of the electrical resistance, thus the time is drawing nearer when they'll be able to take advantage of make a computer that does a tremendous number of calculations simultaneously and that provides unprecedentedly secure computing, impenetrable to hackers.