Chip-based quantum computer using trap technique | Quantum Science Philippines
Quantum Science Philippines

Chip-based quantum computer using trap technique

John Paul J. Aseniero

Computers today are now fundamental part of people’s lives. It is used in a lot of applications such as in business, communication, security systems, sciences and etc. Developing fast classical computer has come to its fundamental limitation and aiming this type of computer would rely on making the device smaller to make chips’ transistor switch faster. However, when they begin to approach 10 nanometers, electrons will start revealing their quantum nature and very strange things will happen. When transistors reach those infinitesimal dimensions and electrons start showing their true colors, this will be the start of vast new frontiers for computing which is based on quantum computers.

Finding something to act as quantum bit or qubit whose quantum state can be read and manipulated is the first thing to remember in building a quantum computer. However, quantum state is a frail thing for it can easily be changed by just a fluctuation of magnetic field or a strong-willed photon interaction. By then, two physicists from Austria’s University of Innsbruck, Juan Ignacio Cirac and Peter Zoller, theorized that a string of ions held fast in a vacuum by an electromagnetic field and cooled to within a few thousandths of a degree above absolute zero could act as stable qubits and form the basis of a quantum computer. There are also research group in NIST that had lot of experience in trapping and cooling ions from their work of atomic clock and one example of their work is trapping beryllium ion as qubit to perform logic operations which is the main key in running a quantum computer.

Even before, physicists have come up with at least half a dozen ways to do quantum computation. This includes using atomic nuclei in organic compounds as qubits and manipulating electrons within superconducting loop. However, it’s hard to handle more than a dozen of qubits which will never lead to an efficient quantum computer that requires hundreds if not thousands. It’s hard to create a full scale ion trap big enough to accommodate that many qubits. Therefore, the only way to build quantum computer is to build the equivalent of quantum integrated circuits. Trap technique is the best way to create these quantum transistors that work the same way like to shrink them down enough and put many of them of the same piece of semiconductor.

Quantum computers could one day replace silicon chips, just like the transistor once replaced the vacuum tube. But for now, the technology required to develop such a quantum computer is beyond our reach. Most research in quantum computing is still very theoretical. There is difficulty in some aspect of building this quantum computer because an equivalent of very large scale integration would require handling the control circuitry just to move the ions around. Five thousand ions would need many dozens of lasers for cooling, detection, and gate operations which should be precisely controlled in coordination with the ions’ motion in the trap. Therefore, this needs a great deal of infrastructure, including a powerful classical computer, to run a useful quantum computer. The most advanced quantum computers have not gone beyond manipulating more than 16 qubits, meaning that they are a far cry from practical application. However, the potential remains that quantum computers one day could perform, quickly and easily, calculations that are incredibly time-consuming on conventional computers. But there is still hope since scientists are running today and plan to run in the near future will almost certainly lead to insights that could make full-scale quantum computing.

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