Global Trend

Quantum Computing Addresses Todays "Insoluble" Problems

Many of the problems of nanotech, biotech, and anti-terrorism are so complex that today¡¯s computers ? based on an architecture defined nearly 60 years ago ? can¡¯t address them. However, hope is on the horizon as researchers get closer and closer to building commercially viable quantum computers.

As we¡¯ll discuss, the economic implications of unleashing this technology promise to be huge. That¡¯s because quantum computers promise to outperform existing computers, despite the tremendous progress that¡¯s been made in the past quarter-century.

In terms of pure computing power, today¡¯s PC is at least 1,000 times as powerful as the original IBM PC announced in 1981. It also actually costs less in inflation-adjusted terms.

Supercomputers designed to solve the thorniest scientific and engineering problems have followed a similar price-performance curve. Red Storm, the new supercomputer being assembled at the Sandia National Laboratories, will be the fastest computer in the world. The $90 million, 41.5 teraflops machine should be installed at Sandia by the end of September and fully up and running by January.

By the end of 2005, the machine should be capable of 100 teraflops, after each single-processor chip is replaced with a new chip that contains two independent processors, each running 25 percent faster than the original chip. The machine, designed by Cray Research, uses massively parallel arrays of AMD Opteron processors, as well as proprietary communications chips manufactured by IBM.

Japan¡¯s Earth Simulator, currently the world¡¯s fastest supercomputer, requires eight megawatts of peak input power, compared to Red Storm¡¯s projected two megawatts. Earth Simulator takes up approximately three times the space.

Yet for all their enormous power, neither Red Storm, Earth Simulator, nor any other conceivable conventional computer can begin to address the really tough problems scientists and others need to solve. For example, modeling the behavior of a neurotransmitter, like serotonin, in the brain would require a conventional computer with more than 1094 bytes of memory. However, there isn¡¯t enough matter in the universe to build such a computer.

But that doesn¡¯t mean that we have to simply give up. The solution lies in applying quantum computing, a radical new technology that could deliver billions of times the world¡¯s combined computing power in a single device. As the August 2004 Business 2.0 explains, it will take only a few seconds for quantum computers to handle computations that would take today¡¯s fastest supercomputers a millennium.

The profits at stake are enormous ? as is the potential boost to human progress. Experts expect that quantum computers will break every encryption code, including those that protect bank accounts and top-secret government communications. They¡¯ll model molecular interactions so precisely that pharmaceutical companies will know the side effects of a drug before it¡¯s introduced to humans. In finance, quantum computers could help manage arbitrage and assess risks.

And, in other fields, quantum computing will change the world in unforeseen ways. In that respect, some experts think quantum computing today is like electricity was in the 1830s.

According to Business 2.0, the history of quantum computing began in 1982, when Caltech physicist Richard Feynman described his vision of a new, super-fast computer in a paper published in the International Journal of Theoretical Physics. The paper outlined Feynman¡¯s concept of a machine that would store information in subatomic particles and operate according to quantum mechanical laws.

Then, in 1994, Bell Labs senior researcher Peter Shor proved that a quantum computer ? if one were ever built ? could ferret out the prime factors of large numbers with blazing speed. As he explained, since ¡°such calculations lie at the heart of the encryption that ensures security for every spy agency, financial institution, and on-line merchant on the planet,¡± the importance of this technology suddenly became apparent.

The next step in defining the concept came three years later, when Colin Williams and Scott Clearwater published Explorations in Quantum Computing. Williams and Clearwater described how such a machine would work. Instead of encoding bits of information in either 1s or 0s like existing computing, quantum computers would store information with photons or electrons, which can exist in two states at the same time. In other words, the bits in quantum computers ? called ¡°qubits¡± ? can represent 0 and 1 simultaneously.

What does this mean? It means that the computing power of a quantum computer is a quantum leap above that of a traditional computer. As Business 2.0 explains, ¡°For comparison¡¯s sake, the task of modeling a serotonin molecule that requires more matter than exists in the universe could be accomplished with only 424 qubits. No wonder biotech, nanotech, and other industries are hoping that quantum computing pans out.¡±

At this point, the hurdles to building such a device are enormous, but progress is being made at a rapid pace. As with any computer, the quantum computer has both hardware and software hurdles to cross before it can become commercially viable.

So far most of the energy has been devoted to the enormous hardware challenges. A useful quantum computer is probably at least a decade away, but researchers already have an idea of how it will work. A conventional supercomputer will serve as the system¡¯s controller. The problem to be solved will be translated into a series of microwave pulses, which program the quantum processor. Quantum computing chips will be kept near absolute zero in a liquid helium refrigerator and lowered into a concrete pit to prevent ¡°decoherence,¡± which is the loss of quantum effects. Computations will be made by the operation of the qubits in the quantum computing chips.

But the same laws of nature that make quantum computers powerful also make them nearly impossible to build. For instance, due to ¡°decoherence,¡± qubits don¡¯t work as well when they interact too much with their environment. For example, you can actually void the ongoing calculation of qubits just by looking at them.

The research is attracting some serious support. The U.S. government has been investing an estimated $80 million a year in quantum computing. At press time, the Defense Advanced Research Projects Agency was expected to announce a 10-year project to build a quantum computer. The project¡¯s budget is rumored to top $200 million.

Two of the pioneers in quantum computing are traditional competitors IBM and NEC. NEC¡¯s qubits use Josephson junction technology, while IBM has been having more success with nuclear magnetic resonance. IBM holds the record with seven qubits maintaining coherence for nearly three-quarters of a second.

However, IBM appears to be abandoning NMR qubits, and experts assert that though NEC has only achieved coherent entanglement of 2 qubits for 10 nanoseconds, it is actually ahead of IBM for two reasons: First, the NMR technology does not appear to be scalable beyond 10 qubits. And second, NEC has discovered not only how to entangle qubits but how to control them in all the ways necessary to build a processor.

The Business 2.0 article focused on an ambitious start-up called D-Wave, located near Vancouver, British Columbia. It¡¯s been in business for five years and was recently funded by Silicon Valley venture fund Draper Fisher Jurvetson. In December 2003, it bought exclusive rights to the Quantronium, a qubit developed by a French government agency. Roger Koch, who leads IBM¡¯s quantum computer team, calls Quantronium ¡°the best qubit around.¡±

In June 2004, D-Wave hired the quantum computing chief who formerly ran the Northrup-Grumman lab responsible for building the Josephson junction qubits for the University of Kansas, which set the current world¡¯s record ? 5,000 nanoseconds ? for non-NMR qubits remaining entangled.

To date, the company has operated two entangled Quantronium qubits for 2,500 nanoseconds. Going forward, D-Wave hopes to shatter every known computing speed barrier, starting with the immediate goal of building four entangled qubits by December 2004, eight by December 2005, 16 by December 2006, and ending up with a 32-qubit processor, computationally as powerful as a Cray supercomputer cluster, by December 2007.

At the same time, research is continuing with the hope of moving away from exotic technologies like Josephson junction and NMR. Much of this fundamental research is being conducted on various university campuses with funding from DARPA and the National Science Foundation, as well as private funding.

At the same time hardware hurdles are being overcome, researchers are trying to work out how to write programs for these almost nonexistent devices.

For example, Stefano Betelli of Paul Sebatier University of Toulouse, France published a paper last year in the European Physical Journal describing the latest effort to develop a quantum programming language. Traditional computers use data bits, which can have a value of either 0 or 1. In a quantum computer, bits are replaced by qubits, which are in a super position of states ? partially 0 and partially 1. It is this super position that allows calculations to be performed in parallel.

Measuring the value of a qubit causes it to collapse into one of two classical bits ? 0 or 1. In a well-organized quantum computation, that should not happen until it becomes necessary to find out what one of the values actually is. But converting this principle into practice is tricky.

The key elements of the language Dr. Betelli and his colleagues have devised are things called quantum registers and quantum operators. The quantum registers are ways for a program to interact with specific qubits. They act as pointers to the locations of qubits within a machine. Those qubits can then be manipulated by the program.

The manipulation itself is done by the quantum operators. These are the equivalent of the logical operators such as ¡°and,¡± ¡°not,¡± and ¡°or¡± that are the basis of classical programming in which an instruction might say, ¡°When A or B and not C are true, do D.¡±

Quantum operators rely on what are known as unitary transformations. The trick is to find a way to describer, in a manner useful to computer scientists, the unitary transformations that underlie a program. Dr. Betelli has managed to do it using object-oriented programming ? long a buzz word among software developers.

As the hardware obstacles begin to fall away, greater emphasis will be placed on research into developing a quantum program language.

The upshot of this research is to show that quantum computing is quickly becoming closer and more practical than ever before. Several industries will be revolutionized by quantum computing. Looking ahead, the Trends editors would like to offer six industry-specific forecasts from Business 2.0 for your consideration:

First, in finance, the number-crunching prowess of the new computers would give a huge advantage to the first users. For example, ¡°a hedge fund with a quantum computer could make a killing on arbitrage ? until everyone else buys one.¡±

Second, in biotech, the technology could speed up the development of drugs. Pharmaceutical companies could use quantum computers to model the effectiveness of new medicines at a level of accuracy that was never possible before.

Third, in meteorology, quantum computers could predict the weather with near-perfect precision. For example, NEC has already developed a supercomputer to predict the weather.

Fourth, in cryptography, quantum computations will break today¡¯s most advanced codes. As a result, it will also make it impossible to send information over the Internet securely.

Fifth, in nanotechnology, quantum computing could open up an entire universe of new products for every industry. It will allow researchers to simulate molecules so they can create new materials that will, for instance, resist fading, shrinking, staining, freezing, melting, or energy loss.

Sixth, in information processing, the entire field will be revolutionized. For example, to look up information on the Internet, a search engine based on quantum computing would make using Google seem as antiquated as going to the public library and manually searching through reference books.

References List :
1. Business 2.0, August 2004, "Quantum Leap," by Paul Kaihla. ¨Ï Copyright 2004 by Time Warner, Inc. All rights reserved.2. International Journal of Theoretical Physics, June/July 1982, Vol.21, Iss 6/7, pp. 467-488, "Simulating Physics with Computers," by Richard Feynman. ¨Ï Copyright 1982 by Nova Science Publishers, Inc. All rights reserved.3. Explorations in Quantum Computing by Colin P. Williams and Scott H. Clearwater is published by Springer Science and Business Media. ¨Ï Copyright 1997 by Colin P. Williams and Scott H. Clearwater. All rights reserved.4. Business 2.0, August 2004, "Quantum Leap," by Paul Kaihla. ¨Ï Copyright 2004 by Time Warner, Inc. All rights reserved.