As we all know, the main building block of any circuit is comprised of logic gates, which perform as information processing units. Nowadays, the time has come for quantum computers to play on the technological ground. Just like in classical computers, logic gates play an important role in transforming information or data. Similarly, for building the circuits in quantum computers, logic gates play a vital role.
In this current technology world, quantum computing has turned into a front line of research in the fields of cryptography, AI, computer algorithms, and much more. We can portray qubits as numerical items with certain particular properties. The excellence of treating qubits as numerical objects is that it gives us the opportunity to develop an overall hypothesis about quantum calculation, which doesn’t rely on an explicit framework for its realization. Also, when quantum standards are applied to data processing, it gives the idea of quantum computing.
Reversible computation has played a vital role in the quantum computing concept. But the question is, why would we choose reversible computation over an irreversible one? To discuss this topic, we have to come across two issues, which are logical reversibility and physical reversibility. This logical reversibility is a process in which any early stage is recoverable in computation backwards or for un-computing the results, whereas, physical reversibility means no increase in physical entropy, according to Landauer’s Principle and the laws of Thermodynamics. For instance, the two input NOR logic gate has one output and it is explicitly irreversible and the NOT logic gate is irreversible. As the NOR gate has two inputs, one of the inputs has been erased in the process effectively and the information of the erased input will be lost. In this way, physical and logical reversibility are connected to each other. And for the physical reversibility, the heat dissipated is taken as the sign of it.
After that, many scientists like Feynman (he stated that a real transistor scatters near 1010 kT of warmth, and surprisingly, the DNA copying mechanism in a human cell scatters about 100 kT of warmth for each bit duplicated), Charles Bennett (he showed the reversibility in classical computation without heat dissipation with the help of a Turing Machine), Peres, and many more took this reversible computation to a great extent. Charles Bennett also showed that the problem that can be simulated in any irreversible machine can also be done in any reversible machine. In this way, some research has been performed in recent technology on this hot topic.
Now regarding quantum computing, why is it the upcoming trend to solve problems in this decade?
The fact behind it is that quantum computers can solve more complex problems which could take billions of years for conventional computers to solve. Recently, the Google AI team discovered a new 54-qubit processor named “Sycamore” which has fast, high-fidelity quantum logic gates in order to execute benchmark testing, according to a study in the year 2020. Furthermore, several technical goliaths like Intel, Microsoft, and IBM have joined the competition to assemble a scalable quantum computer. The current bits of data stored in modern computers are either “0” or “1” and thus it is limited to storing huge volumes of data when faced. Several courses have been conducted nowadays on the topic ‘Quantum Computing’ in several institutions. This field has enormous ramifications for research in medical care, environmental systems, smart materials and much more.
Hence, it can be concluded that by utilizing quantum computers, we can defeat the irreversibility idea of classical computation and stay away from information loss later on.
