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IBM's Quantum Computer Breakthrough

Scientists at IBM Corp.'s San Jose, Calif.-based Almaden Research Center this week rushed to report that they have performed a challenging quantum computer calculation, causing a billion-billion custom-designed molecules in a test tube to become a seven-qubit quantum computer.

With that breakthrough, they solved a simple version of the mathematical problem that is the crux of many of today's data-security cryptographic systems. According to Nabil Amer, manager and strategist of IBM Research's physics of information group, this was quite a feat.

"This result reinforces the growing realization that quantum computers may someday be able to solve problems that are so complex that even the most powerful supercomputers working for millions of years can't calculate the answers," said Amer.

Quantum computers, still largely hypothetical, perform calculations based on the behavior of particles at the sub-atomic level and will be able to process incredibly more millions of instructions per second (MIPS) than today's most powerful binary computer. The underlying science is that data units in a quantum computer, unlike those in today's machines, can exist in more than one state at a time. To put it in layman's terms, quantum computers, would think many thoughts at once, greatly expanding the performance of the machines.

Fundamental data units in a quantum computer are called qubits, which are bits that can take on several values simultaneously. One of the major stumbling blocks to even the most renowned quantum theory scientists is the notion that it is difficult to get particles to behave the way they want them to for a length of time. Disturbances such as electromagnetic fields or discharges will cause the machine to cease working in quantum fashion and go back to single-thought mode, like a binary computer.

What Big Blue's latest, prized calculation did was demonstrate significant factoring capability. Dubbed "Shor's Algorithm," the feat was recorded in Wednesday's issue of the scientific journal Nature and was exacted by a team of IBM scientists and Stanford University graduate students. "Shor's Algorithm" is based on a method forged by AT&T scientist Peter Shor for using the quantum computer to find a number's factors, or, numbers that are multiplied together to give the original number. While factoring a large number is difficult for conventional computers it is simple to verify, so it is used by most cryptographic methods to protect data. So, how did they do this?

The scientists found the factors of the number 15, which requires a seven-qubit quantum computer. IBMers designed and made a molecule that has seven nuclear spins -- the nuclei of five fluorine and two carbon atoms -- which can interact with each other as qubits, be programmed by radio frequency pulses and be detected by nuclear magnetic resonance (NMR) instruments.

They controlled a vial of a billion-billion (10**18) of these molecules so they executed Shor's algorithm and correctly identified 3 and 5 as the factors of 15.

Isaac Chuang, leader of the research team and now an associate professor at MIT, said the next challenge is turning such computations into engineering realities.

"If we could perform this calculation at much larger scales -- say the thousands of qubits required to factor very large numbers -- fundamental changes would be needed in cryptography implementations," Chuang said.

Regardless of the find, IBM conceded in a public statement that true quantum computing is still "many years away." The company believes the first quantum computing applications would likely be co-processors for specific functions, such as solving difficult mathematical problems, modeling quantum systems and performing unstructured searches. Unfazed, IBM pursues the Holy Grail that is quantum computing, with efforts to develop new systems that can better scale to the large numbers of qubits needed for practical applications.

Big Blue is conducting experiments with electron spins confined in semiconductor nanostructures (often called quantum dots), nuclear spins associated with single-atom impurities in a semiconductor, and electronic or magnetic flux through superconductors.