Understanding Quantum Computing (Part 1)

The quantum computers can capitalize on the prowess of atoms and molecules to perform memory and processing tasks. In this way, quantum computing presents an alternative approach to traditional computing which is based on a memory made up of bits. In traditional computers data is encoded into binary digits (bits), each of which assumes either of the definite states o 0 and 1.

The computation process in traditional computers is carried out using electronic transistors and capacitors. Unlike it, however, quantum computing relies on quantum-mechanical phenomena such as superposition and entanglement. Quantum computation uses quantum bits called qubits which maintains a sequence to represent a one, a zero or any quantum-superposition of those two qubit states.

In layman terms, today’s computers operate by manipulating bits that exist in either of the two states of zero or one. Quantum computers are not limited to two states, their ability to encode information into qubits which can exist in superposition. it means it can use symbols of 0 and 1 and all points in between.

Technically speaking, a quantum computer with n qubits can be represented in arbitrary superposition of different states simultaneously. This feature of quantum computation presents an edge over traditional computing that can only be in one of these at

any one time.

Therefore, a quantum computer with the number of qubits equal to the bits of a classical computer is fundamentally different. The following example would help better shed light on the nature of difference between two computing systems. A traditional computing system requi'res storage of complex coefficients 'to represent the state of n-qubit system while state of classical n bit system can be represented with only n numbers.

It points to the exponentially high information storage capacity of qubits than their traditional counterparts can do. In fact, the ability of quantum computers to hold multiple states simultaneously makes them potentially far powerful than today’s supercomputers.

Like traditional computers, quantum computers use algorithm which is composed of fixed sequence of quantum logic gates. The problem is encoded by setting initial value of qubits and then measurement is made by decomposing the system of qubits each with value of zero or one into classical state. The end result, therefore, is at most n classical bits of information.