In the 2011 book “Physics of the Future”, author Michio Kaku predicted that Moore’s Law will end and this would turn Silicon Valley into rust. If an alternative and suitable replacement for silicon was not found. For the last 4 decades, Moore’s Law came about to represent unstoppable technological progress. At its heart was the observation that the number of transistors fabricated onto a chip would double every two years and that the cost would also fall off at a similar rate. It is very important to note that this law is an observation and not an actual physical or natural law. However, as of 2010 the update to the International Technology Roadmap for Semiconductors has shown growth slowing by 2013 after which densities are going to double only every three years. We are hitting the limits of the number of electrons that can be fit in a given area.
One option to overcome this limitation is to create quantum computers that will take advantage of the quantum character of molecules to perform the processing tasks of a conventional computer. Quantum computers could very possibly one day be able to replace silicon chips, just as the transistor replaced vacuum tube.
A quantum computer makes direct use of quantum-mechanical phenomena, like entanglement and superposition to perform operations on data. Transistor based computers required data to be encoded into bits, each of which is always 0 or 1. Quantum computation on the other hand uses Qubits or Quantum bits, which are in superposition of states. One qubit can be used to represent a zero, a one, or any quantum superposition of two qubit states. In general, a quantum processor with n qubits can be in superposition of up to 2^n different states simultaneously at any one time. A quantum processor operates by setting qubits in a controlled initial state that represents the problem at hand and then by manipulating qubits with a fixed sequence of quantum logic gates. The sequence of quantum logic gates to be applied is called as quantum algorithm.
Hypothetically, Quantum computers share the similarities with the probabilistic and non-deterministic computers. One example is the ability of Quantum computer to be in more than one state simultaneously.
In 2011, D-Wave Systems announced the world’s first commercial quantum annealer on the market by the name D-Wave One. The company claims this system usesd a 128 qubit processor chipset. But, there were many criticisms. Criticisms stemmed from benchmark tests published in which the D-Wave Quantum system sometimes performed no better than a reconfigured GPU. Regardless of the criticism, we can consider the tests to be a stepping milestone in computing.
Conclusion:
As of 2014 quantum computing is still in its childhood but many experiments have been carried out in which computational operations were executed on a small number of qubits. Both theoretical and practical research continues, and many military funding agencies and national governments quantum computing research to develop quantum computers for both national and civilian and security purposes. In my view, quantum computing is not a perfect replacement for transistor based computing. It will become a complementary form of computing which will be useful in certain advanced computational scenarios.
References:
http://qist.lanl.gov/qcomp_map.shtml
www.springer.com/physics/applied+%26+technical+physics/journal/11128
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