Introduction of Quantum computers
In the world of computing ,Quantum computing is an exiting and rapidly advancing filed of computer science that leverage the principle of quantum mechanics to perform computations that would be virtually impossible for classical computers .Quantum computing is emerging as a groundbreaking frontier that promises to revolutionize the way we solve complex problem in a different ways and have certain advantages over normal computers for certain problem which come form their ability to be in a huge number of states at the same times whereas a classical computers can only be in a one states at same time.
 |
| fig: Quantum computer |
To understand how Quantum computer works you need to understand the working principle of quantum computer's which are divided into various stages and some of them are as following:
Stages:
-Superposition
-Quantum Entanglement
-Quantum Gates
-Quantum Algorithm
Superposition
Before the study of superposition, you must understand about the Quantum bits as a qubits. The building blocks of a classical computers are known as bits whereas in quantum computers it is called qubits . But they works in fundamentally different from each, as classical bit is kind of switch that can either be in 0 and 1 which you are probably already familiar with a binary and binary information. But a qubits is more complicated.
For a useful visualization you can think of a regular spherical shape have an arrow inside it which is pointing in 3D space. If the arrow is pointing up it is in 0 state and for down it is in 1 state. But they also have a option to be in a both state as a 10,01 which phenomena is called as superposition. When the arrow simultaneously point in both direction also in combination state of 0 and 1 their is raised of superposition.
When we measure a Qubits the output, it gives will still end up being either a 0 or 1 in which to find the perfect output we should depends on a probability which is set by the direction of the arrow. If the arrow is pointing more upwards, you are likely to 0 and at more downward you more likely to get 1 than 0. If it is exactly on the equator you'll get either state with fifty fifty probability. this is the effect of superposition explained.
 |
| fig 1. More downward more 1 fig 2. More upward more 0 |
 |
| fig 1. In equator almost equal probability fig 2. Introduction of probability distributions |
Quantum Entanglement
In quantum entanglement, two or more particles become correlated in such a way that the state of one particle cannot be described independently of the state of the other particles. this means that changes to one entanglement particle will instantaneously effect the others regardless of the distances separating them. this phenomenon is often described as "spooky action at a distance".
 |
| Two particles in entangled state |
In quantum computing entanglement is harnessed to create quantum bits or qubits. Qubits are the fundamental units of quantum information and can exist in multiple states simultaneously, from superposition concept. when qubits are entangled, the , the state of one qubits is intrinsically linked to the state of another, allowing for more complex and powerful computations.
 |
| For visualization how particles entangled with each other |
Entanglement enables quantum computers to perform certain task exponentially faster than classical computers such as factoring large numbers, searching through unsorted database and simulating quantum systems. However, harnessing and maintaining entanglement is practical quantum computing system is s significant technical challenge due to the their susceptibility to environmental interference.
Quantum Gates
Quantum gates are the quantum analogs of classical logic gates. Just as classical bits(0 or 1), quantum gates manipulate qubits, altering their superposition and entanglement properties. Quantum gates play a circuits, where they are combined to execute quantum algorithms.
As a classical computers has various gates its also followed in quantum computing. there are many different gates as follows:
The Hadamard gates
one of the most iconic Quantum gates is Hadamard gate. It transforms a qubit from a definite state (0 OR 1) into superposition state. When you apply the Hadamard gate to a qubit in state0, it becomes an equal superposition of 0 and 1. this superposition is the quantum equivalent of "thinking" in parallel.
The Pauli-X Gate
the Pauli-X gate, often called the quantum not gate, is another essential quantum gate. It flips the state of a qubit, Turing a 0 into 1 and vice-versa. It's analogous to classical bitwise NOT operations but with the added twist of quantum superposition.
The CNOT Gate
The Controlled-NOT(CNOT) gate is a powerful quantum gate used for creating entanglement between qubits. It acts on two qubits, known as the control qubit and the target qubit. the state of the target qubit is filliped only when the control qubit is in the state 1. this gate is fundamental in building quantum circuits for various quantum algorithms.
Quantum Algorithms
quantum algorithms are driving force behind the promise of quantum computing. Leveraging the unique capabilities of qubits, they bring an entirely new level of computational power to the tables. quantum algorithms offers the potential to revolutionize various fields, from cryptography to optimization, artificial intelligence and scientific research. They promise to address problem that were once deemed unsolvable, opening new frontiers in Technology and science.
some different types algorithms are as below:
Shor's algorithms
It is a poster child for quantum algorithms. It's designed to efficiently factor large numbers into their prime components, a task that classical computers struggle with as the numbers grow lager's. Shor's algorithm offers an exponential speed up, making it a potential threat to classical cryptography.
Grover's Algorithm
It demonstrates the quantum advantage in searching unsorted database. Classical computers requires a linear number of step to find an item in an unsorted list, but Grover's algorithm provides a quadratic speed up. this has profound implications for database and search-related tasks.
FAQs
1. What are the potential applications of quantum computing ?
Answer: Quantum computing has the potential of revolutionize various fields, including cryptography, optimization, drug discovery, material science, finance and artificial intelligence. It can solve problems that are currently infeasible for classical computers due to their computational complexity.
2. What are the challenges in building practical quantum computer ?
Answer: Some of the major challenges include qubits stability, error correction, scalability, and the need for extremely low temperatures. Qubit are delicate and prone to errors, making it difficult to build large, reliable quantum computers. Developing error correction techniques is crucial for the advancement of quantum computing technology.
3. How do quantum computers affect cyber security ?
Answer: Quantum computers have the potential to break widely used encryption methods, such as RSA and ECC, through Shor's algorithm. this has led to concerns about the future of cyber security. Researchers are actively working on quantum-resistant encryption methods to protect sensitive information from quantum attacks.
4. Can anyone use quantum computers, or is it limited to researchers and experts ?
Answer: While quantum computing is a specialized field, access to quantum computers is becoming more widely available. Cloud- based quantum computing platforms are accessible to researchers, developers, and even businesses interested in experimenting with quantum algorithms and applications.
CONCLUSION
The working principle of Quantum computing with qubits, superposition, entanglement, quantum gates and quantum algorithms represent a new paradigm in computing. While Quantum computing is still in its infancy and faces significant technical challenges, its potential to transform industries and solve problem that were once deemed unsolvable is undeniable. As the field continues to advance we can look forward to a future where quantum computers play an integral role in addressing some of humanity's most complex challenges.
Description
Quantum computing is a cutting-edge field of computing that leverages the principle of quantum computing mechanics to perform complex calculations at speeds unimaginable with classical. Unlike classical bits that are 0 or 1, quantum bits or qubits can exist in multiple states simultaneously, enabling quantum computers to process vast amount of data and solve problems, such as cryptography and optimization, exponentially faster than traditional computers. Quantum computing has the potential to revolutionize industries and solve problems that are currently intractable with classical computing.
References
- https://www.quantamagazine.org/search?q[s]=quantum%20computing
- https://www.youtube.com/watch?v=-UlxHPIEVqA&t=328s