The first question that comes to our mind when we hear the words “Quantum Computer” is: “Is it related to physics or computer?” “What is this and why do we need them” and many more. Well, such questions are natural to come if you have not heard about them before. It is a complex field. Quantum computing is a hybrid of Physics and Computer science. Quantum computing harness the phenomena of quantum mechanics which includes superposition interface and entanglement to develop computer technology. The devices that perform quantum computations are called Quantum Computers. Quantum computers process information differently. Classical computers use transistors, which are either 1 or 0. Quantum computers use qubits, which can be 1 or 0 at the same time. The number of qubits linked together increases the quantum computing power exponentially. Meanwhile, linking together more transistors only increases power linearly.

EXPLANATION AND WORKING

The existing model of quantum computation describes the computation in terms of a network of quantum logic gates. This model can be thought of as an abstract linear-algebraic generalization of a classical circuit. Since this circuit model obeys quantum mechanics, a quantum computer capable of running these circuits is believed to be physically doable. In quantum computing, a qubit or quantum bit is the basic unit of quantum information—the quantum version of the classic binary bit physically doable with a two-state device.

Unlike a normal computer bit, which can be 0 or 1, a qubit can be either of those or a superposition of both 0 and 1. A memory consist of bits of information has possible states. A vector representing all memory states thus has 2^n entries (one for each state). We begin by considering a simple memory consisting of only one bit. This memory can be found in one of two states: the zero state or the one state.

Well, that is behind the seen stuff. Now how exactly do they work? There are many stages involved in its working:

1. Superfluids: First we use superfluids to chill superconductors. We get these superconductors very cold – about a hundredth of a degree Celsius above absolute zero: the theoretically lowest temperature allowed by the laws of physics.

2. Superconductors: When we put electrons through superconductors they pair up into something called Cooper pairs that quantum tunnel through something called a Josephson junction.

3. Control: Essentially, this is a superconducting qubit. By firing photons at the qubit, we can control its behaviour and get it to hold, change, and read out information.

4. Superposition: A qubit itself isn’t very useful. However, by creating many and connecting them in a state called superposition we can create vast computational spaces. We then represent complex problems in this space using programmable gates.

5. Entanglement: Quantum entanglement allows qubits, which behave randomly, to be perfectly correlated with each other. Using quantum algorithms that exploit quantum entanglement, specific complex problems can be solved more efficiently than on classical computers.

THE NEED FOR QUANTUM COMPUTERS

Until now, we’ve relied on supercomputers to solve most of our problems. These are very large classical computers, with thousands of classical CPU and GPU cores. But, supercomputers aren’t very good at solving certain types of problems that seem easy but actually are way more complex. This is why we need quantum computers. Supercomputers don’t have the working memory to hold the myriad combinations of real-world problems Supercomputers have to analyze each combination one after another, which can take a long time. If a classical computer performs a task in 1 week, a Quantum computer will take one second to do it!

REAL-WORLD EXAMPLES

Google is spending billions of dollars on its plan to build its quantum computer by 2029. The company has opened a campus in California, called Google AI, to help it meet its goal. Google has been investing in this technology for years. As well, so have other companies, such as Honeywell International (HON) and International Business Machine (IBM). IBM expects to hit major quantum computing milestones in the coming years.

IBM Quantum System One: IBM Quantum System One comes with our 27-qubit Falcon processor, demonstrating a quantum volume of 32. The system is upgradeable to our 65-qubit Hummingbird processor and 127-qubit Eagle processor when they become available in late 2023.

REFERENCES:

CONTENT

IBM: What is Quantum Computing? [Internet]. IBM Quantum. [cited 2022Feb19]. Available from: https://www.ibm.com/quantum-computing/what-is-quantum-computing/

Quantum computing [Internet]. Investopedia. Investopedia; [cited 2022Feb19]. Available from: https://www.investopedia.com/terms/q/quantum-computing.asp#:~:text=Quantum%20computing%20is%20the%20study,of%20both%200%20and%201.

Quantum computing [Internet]. Wikipedia. Wikimedia Foundation; [cited 2022Feb19]. Available from: https://en.wikipedia.org/wiki/Quantum_comput

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