Quantum computers are used to solve our daily world problems just like those of classical computers but the way they manipulate the problems differ fundamentally. Now, what factors make quantum computers unique? Well, quantum computers operate on the principles of quantum mechanics like superposition and entanglement. Here is quantum computing information.
Superposition is the unusual property of any quantum object to exist simultaneously in multiple states like that in electrons where one of the states in the electron remains in a lower energy state while the other stays at higher energy levels. So, the electron is prepared for superposition of these two different energy states then there is some probability for the electron to be present in the lower levels as well as some probability to be present in the higher energy states too.
The basic component of information in quantum computing is the qubit which is only possible to understand if we have the idea of superposition beforehand. In classical computers, information is transferred in bits which are the transistors that have two states, 0 and 1 (i.e. off state or on state). In quantum computing, qubits like electrons exhibit lower and higher energy states corresponding to 0 and 1. Qubits are different from classical bits as unlike classical bits qubits must always be in both 0 and 1 state due to their superposition property which states that they have multiple different probabilities which we can manipulate during computation by performing quantum operations.
What is quantum entanglement?
Now, we will talk about another principle of quantum mechanics called entanglement. It is a phenomenon in which quantum particles are defined in such a way that none of them can be recognized without referencing the others. This topic becomes extremely difficult to conceptualize if we consider that entanglement can persist over long distances. If there is any change in the measurement of one particle then that change will immediately be reflected on the other particles making it seem as if the information travelled even faster than the speed of light.
Quantum computers are very fast and they acquire this speed by trying every possible solution to a problem simultaneously. While in real, quantum computer anchorages entanglement between the probabilities related to superposition and qubits in order to carry out a bunch of operations using quantum algorithms such that specific qualities are made highlighted (when there are right answers) and when the others are suppressed (like those of wrong answers). So when we measure the results at the end of computation, we try to make the probability of finding the correct answer maximum. This is why quantum computers are different from that of classical computers.
Need for quantum computing:
The primary need for the development in the field of quantum computing is advancement of the quantum computers developed enough to perform Shor’s algorithm for large numbers. In order to develop a broader knowledge of quantum computing we have to keep in mind that quantum computers are going to generate speedy results only for particular kinds of problems. Research is going on to understand which problems are best suited in order to generate speedy results and simultaneously developing algorithms to solve those problems.
In order to produce faster results we need to produce qubits that would behave the way we ask them to. These qubits are made up of something like, protons, electrons, atoms or molecules etc. Research is going on a large array of qubits that are believed to act as the fundamental building blocks for quantum computers. We all know that qubits are infamous for their not so easy manipulation because any change in qubits can cause decoherence.
Theoretically, it can be said that a quantum computer can perform all the tasks that our classical computer can do. It would not be wise to say that a quantum computer can outperform a classical computer in all types of tasks especially when the cost is factored in the equation. If the classical algorithms are used in a quantum computer then the calculations would simply be performed like in a classical computer. In order to fully utilize the capabilities of the quantum computer, it has to be used with new algorithms that are especially meant for quantum computing. These new algorithms are called quantum algorithms and they can exploit the quantum parallelism that is not possible in any classical computer. Simply said, if we want to achieve something greater with quantum computers than the classical computers, special methods have to be used.
Quantum algorithms are extremely difficult to formulate and it takes a lot of research in the field with a lot of time and resources for discovering what might work. If we take the example of the quantum algorithm by Peter Shor that tackles the problem of factoring large numbers into its prime factors and it is considered to be one of the most difficult problems to solve using the classical computer. The algorithm by Peter Shor is very clever in its use of quantum parallelism to solve the problem. This algorithm can give the result in seconds whereas the classical computer will take an unimaginable amount of time to produce the same result.
The cost of the quantum computer is a great disadvantage. Even IBM’s first quantum computer was proposed to be made public on a subscription basis ehic would be based on demand only. It will be a really long time until the price of quantum computing becomes so popular to make its price reasonable.