A recent study revealed that the basic underlying mechanisms of quantum computing – a potentially ultrafast method of computer processing – are viable. A fully operational quantum computer would be nothing short of revolutionary; with this in mind, Google appears to have officially declared that its D-Wave system is able to use quantum physics to calculate complex mathematical algorithms.
Conventional computers communicate and store information and data in bits using binary language. Quantum computing uses qubits, which take advantage of the fact that particles can exist in multiple states at the same time – this is known as superpositioning. If a particle exists in two states simultaneously, these can be combined to produce a third state. Therefore, if one state is represented by a 1, and the other is the 0, the superpositioned state can represent a combination of the two.
Quantum computers are entirely based around this concept, meaning that they can hypothetically store data across multiple states at the same time, allowing them to process information millions of times faster than conventional computers using binary programming language.
It's been claimed that the so-called quantum computer purchased by Google from the company D-Wave can do just that, with new results apparently showing that it can perform calculations 100 million times faster than a conventional computer.
It is a specialized device called a quantum annealer, which performs calculations within a landscape of hills and valleys of energy; the hills represent high-energy states, and the valleys the low-energy states. The lowest valley on the landscape represents the solution to the problem being analyzed.
Normally, the qubits containing the information have to “settle” in this low valley by exploring pathways through the landscape, but the D-Wave computer is able to circumvent this normally lengthy process using “quantum tunneling.”
In certain situations, despite not having enough energy to reach a different energy state, some particles are able to “tunnel” through the energy barrier that they would normally have to surmount. This quantum effect shortens the conventional sequence of events considerably. In the same way, the qubits inside D-Wave are able to tunnel through these energy hills in order to find the solution to a problem at lightning speeds.
Some experts are skeptical: Matthias Troyer, from the Swiss Federal Institute of Technology in Zurich, notes that the testing algorithm was designed in order to be very difficult for the conventional computer to solve, but relatively easy for D-Wave, regardless of its ability to use quantum tunneling.
Leveling out the playing field and giving both computers an equally difficult algorithm to handle would reduce the advantage to just 100 times faster. “A claim of [a 100 million times] speedup is thus very misleading,” Troyer told New Scientist.
Even their own engineers confess that D-Wave may just exhibit quantum behavior, rather than being a bonafide quantum computer. Undoubtedly, the controversy surrounding D-Wave will continue for some time – but perhaps we haven’t quite reached the age of quantum computing just yet.
[H/T: New Scientist]