By Akshay Asija
Computers, as we know them, have been conceptually similar for close to seven decades. There have been major performance improvements in computers during this time, owing to an exponential increase in the number of binary transistorstiny power switchesthat can be packed on a single silicon microprocessor. Higher the number of transistors on a chip, the greater is the number of parallel calculations that can be performed at a time, and consequently, the higher is the chips processing speed.
Recent developments by researchers at several universities as well as by technology giants like Google and IBM have accelerated the development of quantum computing, which is a completely new (and different) paradigm of computing. The concept of quantum computing springs from the theories propounded in the 1980s by American theoretical physicist Richard Feynman. Feynman proposed that significant improvements in processing speed could be achieved with a quantum computer.
The technology behind quantum computers
Conventionally, computers have processed information using two optionson and off. Information is stored in binary digits (or bits) which can only take 1 or 0 as values. Based on the users requirement, these bits are processed by the transistors present on a microchip. Even though modern microprocessors have billions of transistors, they are limited in comparison to the number of binary operations the processors need to perform. This is a limitation that can potentially be addressed by quantum computers.
Quantum computers operate on information stored in ‘qubits’, which have an uncertain physical state, allowing for information to be stored in more ways than just the binary form. This is because, in quantum physics, particles can act like waves, so that they can be particle or wave or particle and wave. This is called superposition, a property by which a qubit can be a 0 or 1 or 0 and 1. An important aspect of superposition is that a single qubit can be used to perform two equations simultaneously, while two qubits can perform four and three qubits can perform eight, and so on (an exponential expansion). Thus, the scale and the scope of a quantum computers working concepts is beyond that of binary computers.
For instance, solving a problem with equally likely outcomes is a taxing task for a binary computer, involving an individual assessment of each outcome. This requires a longer time than that required for regular tasks, making binary computers unsuitable for such problems. Quantum computers can, on the other hand, assess multiple probabilities at a time, through the concept of ‘quantum entanglement’. In the simplest of terms, quantum entanglement refers to the situation that arises when two sub-atomic particles (such as qubits) become entangled, and anything that happens to one of these particles happens to the other. The essence of quantum computing is about using quantum entanglement to solve problems that regular computers cannot.
Effect on networks and internet
Quantum entanglement also opens up new avenues for development in another domaincomputer networks and the Internet. Instead of transmitting data in the traditional way by sending signals across a link (such as a wire), quantum networking relies on quantum entanglement to create pairs of entangled photons. The sender and recipient each receive one photon from a pair. Being entangled, each photon mirrors the state of the other photon in the pair. Thus, the sender only needs to make changes in its photon, which are mirrored in the receivers photon, without any actual transmission of information. Hackers cannot access data that is not travelling, which means quantum internet would be much more secure compared to the internet of today. As far-fetched as it may sound, a working prototype of the quantum internet has been developed by researchers at Hefei University, China.
Is quantum computing the future?
While we are remarkably close to using quantum computers and internet in our everyday lives, there still are many roadblocks on the way to a full-scale implementation. To begin with, quantum computing still isnt quite as polished as the binary computing we are used to. For instance, quantum processors developed so far function only at perfect-zero temperatures. However, at the current pace of development, we are quickly on our way to using computers that are unimaginably small and omnipresent while being virtually immune to hacking attacks, thanks to quantum encryption. Quantum computing and internet will also revolutionise the field of artificial intelligence and machine learning, which is curtailed, to some extent, by the limitations of our current computers.
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