How Do Quantum Computers Work?

All the computing devices rely on a very basic ability to store and manipulate information. The classical computers manipulate individual bits and store information as binary 0 and 1 states. But in quantum computers, that’s not the case. Information is stored in something called qubits. Now, what are these?

We know that classical computers can store information in either binary 1 or 0. No exception! But in quantum computers, information can be stored in a superposition of 0 and 1. Take for example the spin of an electron. It can have 2 values: up or down. But you can only know the correct value of spin after you measure it. Before that, it’s in a superposition state: a combination of both up and down. This is a qubit. The information is stored in the state of the quantum particle. Undoubtedly, the idea of Quantum Computing is very fascinating, but it is equally complex to implement in the real world. The Qubits are the building block of a Quantum Computer. So, to build a Quantum computer, the first task is to generate Qubits. The qubits can be generated using atoms, ions, electrons, photons, etc. Now, maintaining a quantum state for a long time is another major challenge. One of the known methods uses superconductivity to create and maintain a quantum state. To work with these superconducting qubits for extended periods, they must be kept very cold. Any heat in the system can introduce error, which is why quantum computers operate at temperatures close to absolute zero, colder than the vacuum of space. And all these requirements are quite strenuous to be realized in reality! The world’s first tiny quantum computer was built in 1997. And today, many players are engaged in this battle to build the most powerful quantum computer. These include some known commercial entities like IBM, Google, Alibaba, Microsoft, Intel, and a lot more, all willing to spend billions of dollars on quantum computing development and research. Quantum computers have the potential to process exponentially more data as compared to classical computers. An n-bit classical computer can store only n amplitudes of information. Whereas, an n-qubit quantum computer can store 2^n amplitudes of information. This means that a 500 Qubits quantum computer can store more amplitudes than our estimate of the number of atoms in the Universe! Quantum computers can spur the development of breakthroughs in various fields, be it security systems, finance management, research, medications, and a lot more. But these are not very useful as far as our daily tasks of watching Netflix, writing an email, etc. are concerned. The classical computers work perfectly well for such tasks. These are not places where quantum computers will help you. But, even when the first classical computers were built, people had the same impression about them being useful only to scientists, and the rest you know. So, only the time will tell what the Quantum computers have in store for us! That’s it for this edition, make sure you share this video! See you in the next episode of Q And A.SHOW LESS