NEC Corporation, Japan Science and Technology Agency (JST) and the Institute of Physical and Chemical Research (RIKEN) have together successfully demonstrated the world's first quantum bit (qubit) circuit that can control the strength of coupling between qubits. Technology achieving control of the coupling strength between qubits is vital to the realization of a practical quantum computer, and has been long awaited in the scientific field.
The quantum computer, when it is finally brought to fruition, is expected to far surpass the capabilities of even the most modern of today's supercomputers. Actual computing in a quantum computer is carried out by manipulating the quantum state of qubits in time sequence by external controls. To achieve such manipulation, it is necessary to control the: 1. States of individual qubits, 2. States of two qubits (logic operation), and 3. Ability to turn on /off the coupling between qubits.
NEC, JST, and RIKEN have already announced successful development of key technologies for the world's first solid-state qubit and the world's first two-qubit logic gate, based on solid-state technology that excels in its ability to integrate qubits. Following these achievements, the research group addressed the controllable coupling of qubits as the next logical step in realization of a practical quantum computer. Their new research result represents the world's first successful demonstration of controllably coupled qubits.
To date, the coupling of qubits has been difficult to control. In order to realize this control, the research group devised an original mechanism that employs another qubit in between the two qubits for coupling. The coupling qubit functions as a non-linear transformer that is able to turn on and off the magnetic coupling between the two qubits, and on/off control is achieved simply by inputting a microwave. Moreover, coupling operation has been achieved without shortening the lifetime of each qubit. Scalability is also realized through the repetition of coupled two-qubit units - a feature necessary for future quantum computers.
To demonstrate the operation feasibility of the controllable coupling scheme, the research group employed a coupled two-qubit system, the smallest quantum logic unit, to carry out a multi-quantum control experiment involving the turning on and off of the coupling. As a result, a simple quantum protocol has been successfully demonstrated, allowing controllable coupling for the execution of quantum algorithms.
In the near future, NEC, JST, and RIKEN, plan to implement a larger-scale, more elaborate quantum computation, aiming for the realization of a practical quantum computer.
The result of this joint research will be published in the May 4th issue of the international weekly science journal, Science, published by the American Association for the Advancement of Science (AAAS).
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Spintronics Technology In 1994, Bandyopadhyay and colleagues were the first group to propose the use of spin in classical computing. Then two years later, they were among the first researchers to propose the use of spin in quantum computing. The recent work goes a long way toward implementing some of these ideas.
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Research: Ion Trap Physicists at the National Institute of Standards and Technology (NIST) have designed and built a novel electromagnetic trap for ions that could be easily mass produced to potentially make quantum computers large enough for practical use. The new trap, described in the June 30 issue of Physical Review Letters,* may help scientists surmount what is currently the most significant barrier to building a working quantum computer—scaling up components and processes that have been successfully demonstrated individually.
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A Quantum Computer, One Dot at a Time Quantum computers do not yet exist, but it is known that they can bypass all known encryption schemes used today on the Internet. Quantum computers also are capable of efficiently solving the most important equation in quantum physics: the Schrödinger equation, which describes the time-dependence of quantum mechanical systems. Hence, if quantum computers can be built, they likely will have as large an impact on technology as the transistor.
Better Memory with Quantum Computer Bits Physicists at the National Institute of Standards and Technology (NIST) have used charged atoms (ions) to demonstrate a quantum physics version of computer memory lasting longer than 10 seconds—more than 100,000 times longer than in previous experiments on the same ions. The advance improves prospects for making practical, reliable quantum computers (which make use of the properties of quantum systems rather than transistors for performing calculations or storing information). Quantum computers, if they can be built, could break today’s best encryption systems, accelerate database searching, develop novel products such as fraud-proof digital signatures or simulate complex biological systems to help design new drugs.
Combining diamond anvils and powerful lasers, laboratory researchers have developed a technique that should be able to squeeze materials to pressures 100 to 1,000 times greater than possible today, reproducing conditions expected in the cores of supergiant planets.
Until now, these pressures have only been available experimentally next to underground nuclear explosions.
Earthrace started undergoing engine repairs in Koror, 26 April 2007, however the damage has been more extensive than originally anticipated.
Earthrace Captain, Pete Bethune, says on removing the head, one of the exhaust valves was found to have a 5mm x 5mm square chip missing from one side, with no suggestion as to what might have caused the failure.
In recent years, the science of biology has been dominated by genomics – the study of genes and their functions. The genomics era is now making way for the era of proteomics – the study of the proteins that genes encode.
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