What are Quantum Computers?

Recently, the term AI (Artificial Intelligence) has become quite familiar, as it is frequently mentioned not only in IT fields but also in other areas like finance, manufacturing, design, and education. Alongside AI, another important term to be aware of is Quantum Computing, which I believe will have a significant impact on the IT industry.

For beginners like myself, quantum computing can seem complex to catch up with. I’ll try to explain it as simply as possible through this article. You might wonder why quantum computing is necessary and what problems it can solve that traditional (classical) computers cannot. I hope you find this article informative and useful.

1. Introduction

The origins of quantum computing trace back to the early 20th century. In 1900, German theoretical physicist Max Planck introduced the Quantum Hypothesis, marking the beginning of a new era in physics and paving the way for quantum computing.

Another key contribution to the development of quantum computing came from Werner Heisenberg, who, in 1927, introduced the Uncertainty Principle.

According to Moore’s Law, the limitations of traditional computers have prompted significant investment from companies and startups striving to build the world’s most advanced quantum computers. This investment has invigorated the quantum computing industry.

Quantum Industry Growth

2. What is Quantum Computing ?

Quantum computing is an emerging field at the forefront of computer science, leveraging quantum physics principles to address problems that are probabilistic and unpredictable, known as intractable problems. They believe these problems are currently beyond the reach of even the most powerful classical computers. Therefore, they are back to quantum mechanics, the study of subatomic particles, which reveals unique and fundamental principles. Quantum computers utilize these principles to perform computations probabilistically and quantum mechanically.

3. What are Quantum Computers?

While classical computers use binary digits, or known as bits, as the fundamental unit of computation, quantum computers use quantum bits, or qubits. Unlike classical bits, which can be either 0 or 1, qubits have more complex properties. To understand how quantum computers work, it’s essential to know about three key features:

a. Superposition

Qubits work based on quantum particles’ characteristics, such as the spin of an electron or the orientation of a photon. Consequently, qubits can exist in multiple states simultaneously. To better understand, we can imagine a qubit as an arrow in 3D sphere space: if the arrow points up, the qubit is in the 0 state; if it points down, it is in the 1 state. Additionally, the arrow can point in any other direction, representing a superposition state. In this state, a qubit represents a combination of 0 and 1. Unlike classical bits, which are strictly either 0 or 1, a qubit can simultaneously represent any proportion of both states. However, when measured, a qubit will end up to present either 0 or 1, based on the probability determined by the direction of the arrow.

Quantum Computing Explanation

b. Entanglement

In classical computers, the state of a bit is determined by predefined instructions and controlled by switches or transistors, operating independently. In quantum computers, qubits can become connected, forming a larger quantum state. Entanglement means that a change in the state of one qubit affects its entangled partners instantaneously, regardless of distance. Thus, if the state of one qubit is altered, the entire system’s probability distribution must be recalculated, growing exponentially with the number of qubits. In essence, a system of n qubits can represent 2^n different states. This leads to the ability to handle vast amounts of information simultaneously, which distinguishes quantum computers from classical ones.

c. Interference

Understanding interference can be challenging. In reality, the state of a qubit is not exactly like the 3D sphere described earlier but is better represented as an abstract entity known as a quantum wavefunction. This wavefunction encapsulates the characteristics of a quantum state. When qubits become entangled, they form a combination of quantum wavefunctions. Like classical waves, these quantum wavefunctions can interfere with each other, either combining to form a larger wave or canceling each other out.

4. What are the new expectations?

Quantum computers are anticipated to play a crucial role in addressing several technology challenges:

a. Database Searching

Classical computers must scan each entry individually, while quantum computers can perform this operation simultaneously, improving search efficiency.

b. Factorization Problem

One of the most impactful algorithms in quantum computing is Shor’s Algorithm, named after mathematician Peter Shor. This algorithm shows how large numbers can be factored exponentially faster than classical methods.

c. Simulation Applications

Applications requiring extensive resources for rendering images and lively movements may be beyond the capabilities of classical computers. Quantum computing is believed to simulate systems with atomic-level precision, potentially revolutionizing fields such as medicine, agriculture, electric vehicle design, and financial security tracking.

5. What challenges are we facing?

a. IT Security

Quantum computers could significantly impact IT security due to their ability to perform factorization far more efficiently than classical computers. While classical computers might take years to decipher a private key from a public key through trial and error, it is believed that a sufficiently advanced quantum computer could achieve this in a matter of hours. As a result, developing new security standards is crucial to protect sensitive data. This challenge will be a major concern for governments as they seek to secure information related to banking, politics, healthcare, and other critical areas.

b. Advancements in Other Fields

Mr. Tony Uttley has highlighted that simulating natural processes, such as how plants create fertilizer at room temperature, could lead to significant agricultural breakthroughs and help conserve resources used in fertilizer production. The first individual or country to develop this formula could become a game changer in this industry.

6. Summary

Quantum computers are not expected to replace classical computers entirely, as they often need to operate in highly controlled environments at temperatures close to absolute zero, which only large, well-funded organizations can currently manage. Traditional computers will remain essential for day-by-day tasks in the near future. However, due to its global implications, it is important to stay informed about quantum computing and its potential implications from now on.