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Day 51 – Q 2.What is quantum computing? How can it change the way computers perform? Examine.

2. What is quantum computing? How can it change the way computers perform? Examine. 

क्वांटम कंप्यूटिंग क्या है? यह कंप्यूटरों के प्रदर्शन को कैसे बदल सकता है? जांच करें।


Quantum computing is a new type of computing that relies on quantum physics unlike traditional computing which is based on binary processing of information.  It uses ‘qubit’ built by the way of some objects behave at the subatomic level or at extremely cold temperature.


Changing the computer performance:

Exploiting the principles of quantum mechanics, quantum computing help computers to easily tackle computational problems that may be tough for the classical computer as the size of the numbers and number of inputs involved grows bigger. It uses the fundamental laws of quantum physics to perform an incomprehensible number of calculations simultaneously.

  • Qubits: Unlike binary bits which can be either ‘1’ or ‘0’, qubit can be both ‘0’ and ’1’ at the same time which is called quantum superposition. This helps the computer hold more information. Two qubits can hold four values at once. And as the number of qubits grows, a quantum computer becomes exponentially more powerful. E.g. Google’s quantum computer ‘Sycamore’ took under 3 minutes for a calculation that would take a supercomputer 10,000 years.
  • Quantum computing uses the principle of entanglement which means they can manipulate all their qubits simultaneously. Thus, instead of doing a set of calculations one after another, a quantum computer could do them all at the same time.
  • Parallel computing: It can simulate several classical computers working in parallel and hence change the fundamental way of working of computers. E.g. Bell Labs in 1996 discovered that a quantum computer would be able to do a task with one thousand steps instead of a million taken by classical computer.
  • Encryption and security: several encryption systems used in banking and security applications are premised on computers being unable to handle mathematical problems that are computationally demanding beyond a limit. With quantum computing, the way of computer encryption needs an upgradation. At the same time, quantum computing also can be a solution with quantum encryption methods that can be employed.
  • Instead of troubleshooting issues bit by bit as we do now with classical computers, quantum computers tackle the entire problem at once. This opens the door for amazing developments in every field from financial services to our national security.

Quantum computers reduces the number of computers and hence reduce the physical space and energy requirements. With these advantages, it has applications in every field from AI, Banking, Defence applications, Big data analytics, Medicine and so on.

However, a more careful analysis show that quantum computing still has limitations specially in solving real time problems. There are still hardware issues, unique propensity to errors and are not as amenable to executing real world problems as super computers.  


Thus, quantum computing is a revolution in the field of computing and is an upgrade of the present-day supercomputers. USA and China are taking lead in quantum computing. The need to invest in quantum computing researches is realized by India which has unveiled a programme called Quantum-Enabled Science & Technology (QuEST).

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