Moore's law, the basis of all advancements in chip technology. For years this law has been inspiring chip designers and fabricators to push all physical limits and create faster and better processors, and hence keeping the law valid. Almost every 18-20 months a new chip with double the speed than its predecessor is introduced. However, this trend won't continue for long. With every new generation of processor, designers push track widths, transistor sizes to smaller and smaller sizes. 65nm to 45 nm to 32 nm... These fabrication process will keep going smaller until they reach near atomic sizes. That's the point where physical limits can't be further pushed to accommodate more transistors into the chip. Such a time would come very soon. But does that mean all advancements in computer technologies would suddenly come to a halt? The answer is a definite NO. All the great minds inhabiting our world won't let such an apocalypse come. They have an answer :Quantum Computing
At near atomic sizes objects don't behave normally. They are not governed by the laws of normal physics but, rather by quantum physics. At atomic sizes, objects behave strangely and these strange behaviors are taken advantage of by quantum computing.
Modern day computers use bits or 0s and 1s to store and process data. Quantum computers use qubits to do the same. Qubits also represent states of 1s and 0s like bits. But, apart from these two states they have a third state that can represent both 0 and 1 at the same time. This is a property possible only at atomic sizes. Such a phenomena is called superposition. To understand how this translates to computing powers exponential times more than current generation processors I present a simple example- consider 4 bits representing a register. This register can have 2^4 combinations. But, at a time only one of these 2^4 combinations can be stored. Now replace the 4 bits by 4 qubits. Each of these qubits can represent both 0 and 1 at once. So the 4 qubits can represent all 2^4 combinations at once. So the qubit based register can store all these values at once. Consider another example: suppose an algorithm requires to operate on 2^n numbers. If n bits are used to represent each of these 2^n bits then to operate on all of 2^n numbers would require 2^n steps. These numbers if represented using qubits would require just 1 step.
Quantum computing unleashes true multiprocessing. A problem that would take a modern day computer years to compute can be solved by a quantum computer in minutes. A typical case is integer factorization. To factorize a 1000 digit integer would take even the best of supercomputer time close to the age of universe. This is the reason why cracking the codes of encryption systems like AES is almost impossible. All public encryptions use the difficulty in factorizing long integers to their advantage. These use such numbers only as their codes. For a quantum computer it would be just a matter of minutes to crack such a code.
A quantum computer on your desk or in your hand may still be a good 40 to 50 years away but, whenever it comes it would revolutionize computing. It’s going to change our lives and make totally surreal things a reality.
Pity I was not born in the quantum age.
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