While the world’s fastest supercomputer currently resides in Japan, IBM might soon trump all supercomputers in the world with its quantum computing technology. While IBM is not nearly there yet, breakthroughs in quantum computing might mean that computers might be exponentially more powerful than today’s so-called “classical” computers.

Scientists from IBM have announced earlier this week that they have made breakthroughs that have put the team “on the cusp of building systems that will take computing to a whole new level,” referring to quantum computing. Researchers have been able to extend the time at which quantum bits or “qubits” retain their integrity, which brings the engineers “close to the minimum requirements for a full-scale quantum computing system as determined by the world-wide research community.”

# Still Experimental

Even with these breakthroughs, though, quantum computing still remains to be experimental. There are no practical quantum computers at this time, although researchers have been building experimental computers for years. The concept of quantum computing was actually introduced in 1981, when particles of matter were posited to be able to exist in multiple states — such as “on” and “off” — at the same time. In contrast, traditional digital computing would work within physical limitations of matter, which means that each bit can either be “on” or “off” but not both, at the same time.

Once quantum computing gets practical uses, even the smallest computer can be more powerful than today’s supercomputers. IBM researchers highlight it as such.

The special properties of qubits will allow quantum computers to work on millions of computations at once, while desktop PCs can typically handle minimal simultaneous computations. For example, a single 250-qubit state contains more bits of information than there are atoms in the universe.

IBM researchers elaborated on the practical applications of quantum computing. For example, even the strongest encryption algorithm today can be cracked in a matter of seconds. Other possible applications include “searching databases of unstructured information, performing a range of optimization tasks and solving previously unsolvable mathematical problems,” the team adds.

# Building Qubits

Current research is based on building systems that can solve the so-called “decoherence” problem, referring to how quantum systems easily decohere, dropping from two simultaneous states into just one. Researchers are currently using states of superconductivity — by cooling certain substances to very low subzero temperatures — in which resistance becomes essentially zero.

The aim is to keep the qubits in a quantum state for as long as possible. The threshold is 10 to 100 microseconds, says Matthias Steffen, who manages the IBM research team that focuses on developing quantum computing with the aim of applying the technology for solving real-world problems. A decade ago, researchers were able to put qubits into a quantum state for about a nanosecond. Today, researchers have reached the ideal threshold with a “three-dimensional” qubit, which means superconductivity performance has increased 10,000 times.

Our demonstration of a two-qubit device — an elementary logic gate — is also good enough to get at least close to the threshold needed for a practical quantum computer. We’re not quite there yet, but we’re getting there.

The next step is putting all those qubits together and finding a practical means to put these on a chip. “How do you put it all together?” asks researcher Steffen. Perhaps IBM might want to turn to China, where practically everything is built today.

Via *PC Magazine* and *Wired*