Quantum computing is a significant leap in computer technology. These complex computers can solve challenging calculations within minutes while analyzing a wide range of data at subatomic levels. Because quantum computing is efficient and robust, several sectors, such as AI, logistics, manufacturing, weather forecasting, and finance, can optimize their operations, leverage real-time data, and make strategic decisions quicker.

This guide will explore quantum computing, how it works, the advantages and challenges of this technology, and its leading applications.

## What Is the Purpose of Quantum Computers?

The purpose of quantum computers is to process large volumes of information and complete high-level data-oriented tasks (i.e., simulations and analysis) much quicker and more accurately than what standard computers allow. These computers use quantum theory principles to solve complex problems that standard computers cannot. The term “quantum” expresses “the smallest discrete unit of a phenomenon”. For instance, the quantum of electricity is an electron, and for light, it’s a photon. Quantum theory describes how energy and material behave at subatomic levels, such as individual atoms, photons, electrons, and other elementary particles.

Quantum computing uses these physics to perform data-intensive tasks (i.e., molecule simulations, AI algorithm tests, drug research) too complex for classical computers. Because of this, many industries leverage quantum computers. For example, weather forecasting—classical computers take longer to analyze rapid weather changes. However, quantum computers can keep up with real-time updates and provide more accurate forecasting. Another use case of quantum computing is financial modeling; companies can simultaneously analyze numerous investment portfolios to find the best one.

Furthermore, quantum computing is becoming an increasingly popular technology, as research by MarketsandMarkets confirms the market reached $886 million in 2023. By 2029, it is expected to increase to $4,375 million at a compound annual growth rate (CAGR) of 38.8%.

## Quantum Computers vs. Traditional Computers

The primary difference between quantum and classical computers is how they process code. While both technologies represent information as ones and zeros, quantum computers can represent these values at the same time, so code can exist in both states. However, standard computing can only represent values as one or zero, which means values can be present in one of two states.

Additionally, quantum computer hardware must be kept at ultracold temperatures of about -459℉/-273℃ and are prone to errors because of how complex processing such high volumes of data, at the subatomic level, is. On the other hand, traditional hardware can sustain at room temperature and is not as error-prone.

Ultimately, general-purpose computers are best for everyday tasks because they are practical and affordable to the public. In contrast, quantum computers are better for data analysis, simulation, and optimization due to the intricate information processing technology.

## Quantum Computers vs. Supercomputers

Supercomputers are more advanced than general-purpose computers, but are less robust than quantum computers. The aim of supercomputing was to simulate physics in a computer, and since scientists could invent this technology, they could also evolve into quantum mechanics.

There are many notable similarities between quantum and supercomputers. Both technologies process complex problems and large volumes of data and are used to perform one specific task (i.e., weather forecasting) rather than a wide range of functions like their classical counterparts.

Overall, super and quantum computers are very similar; quantum mechanics is simply more sophisticated and able to process much more robust data than supercomputers.

## The Key Components of Quantum Computers

Quantum computing operates on multiple complex components that enable quantum mechanics to exist in computers. These components include qubits, entanglement, superposition, and decoherence, which allow computers to code, process, analyze and simulate data at subatomic levels. Here are a few of the fundamental elements of quantum computing.

**Qubits **

Quantum bits form the foundation of quantum computing. These computers encode information in qubits, while classical computing does this in bits. The difference is that each bit represents a value (either 1 or 0), but quantum bits can represent both values at the same time. Furthermore, qubits can either be expressed as a linear combination of both values (unlike bits) or as ∣0⟩,∣1⟩.

**Entanglement**

Another component of quantum computing is entanglement—when two qubits exist as a pair on the same quantum level (despite the distance between them). When one quantum bit experiences change, this will directly affect the other predictably. In addition, when two systems are correlated, they do not share this correlation with a third party. As a result, quantum cryptography relies on entanglement to exchange data between two parties through a secure channel using encrypted code, making it nearly impossible to copy information in this encoded state.

Another example of how quantum computers rely on entanglement is to transform high-latency bandwidths into low-latency bandwidths. This quantum computing component transfers half the data from high-latency channels to support the information processed by low-latency channels.

**Superposition**

Superposition describes the phenomena of quantum bits existing in multiple states simultaneously; these units can represent values of one and zero at once. As a result, quantum computing solves complex calculations quickly and accurately, as it considers a broad scope of data at once. Without superposition, it is impossible to do quantum computing. This phenomenon also allows quantum interference—scientists can filter unwanted quantum states and only work with those that accurately describe the solution they need.

**Decoherence**

Decoherence obstructs the progress of quantum computers, as it collapses quantum particles in a superposition state. This component of quantum technology causes many errors in calculations and makes it challenging to preserve superpositions long enough to successfully analyze them. To prevent this, researchers store quantum bits in vacuum chambers and supercooled fridges, protecting them from the outside world. Another solution scientists have discovered to lengthen coherence and rectify decoherence errors is Quantum Error Correction (QEC).

## The Advantages of Quantum Computers

Due to the elements of quantum computing, these technologies enable researchers to solve complex calculations and optimize energy consumption and efficiency when processing high volumes of data.

**Increased Efficiency **

Operating on superposition and entanglement enables quantum computers to process large volumes of data for elaborate problem-solving with optimal efficiency. For instance, Google developed a quantum computer that solved a calculation in four minutes, compared to its supercomputer, which would have taken ten thousand years to complete.

**Complex Problem-Solving **

Since quantum computers rely on entanglement and superposition, they can solve variables that super and classical computers cannot. When classical and supercomputers are unable to solve calculations, it is usually because the degree of complexity is too much for these systems to process. For instance, to solve problems involving logistics, classical computers use brute-force algorithms, but quantum computers can evaluate all the data at once.

**Significant Energy Savings **

Quantum computing consumes much less energy than traditional and supercomputing as they process high volumes of data in parallel. Conventional computers use billions of transistors to calculate problems, while quantum computers use only millions of qubits, resulting in significant energy savings.

A NASA study comparing the energy consumption between super and quantum computers found that the former consumed a maximum of 97 MWh, while the latter only consumed 4.2×10−4 MWh.

## The Challenges of Quantum Computers

Quantum technology poses many challenges because of how robust and complex these systems are. It is difficult and costly to adopt quantum technology, there is a lack of trained experts, and it may disrupt existing IT infrastructures. Here are a few of the major challenges businesses must consider for quantum computing.

**Difficult and Costly Development**

The most prominent challenge of quantum computing is the complexity and cost of developing this technology. According to information from SEEQC, just one qubit costs around $10,000. Based on data by PureVPN, a portable quantum computer with two qubits costs around $5000, while one with 200 qubits is about $15 million. Furthermore, implementing a quantum computing campaign to solve just one problem would cost over $10 billion. Ultimately, the high cost of quantum computing makes it an inaccessible option for many businesses.

**Inadequately Trained Staff**

Another obvious drawback of quantum computing is a lack of adequately trained experts. Because this technology is new and highly complex, it may prove challenging for even the most experienced programmers. However, this does not only apply to configuring a quantum computing infrastructure but maintaining it as well—because these computers operate on quantum mechanics, they have many error problems, and it is severely problematic to control this software.

**Incompatible With Current IT Infrastructure **

A third challenge of quantum computing is migrating these computers into your current IT infrastructure—they are too different from traditional computing, which may completely disrupt your existing framework. The high volumes of data processed by quantum computers are too excessive for classical IT infrastructures, and they cannot maintain the load.

## Quantum Computer Applications

Quantum computing is widely used in AI, logistics, drug development, manufacturing, and maintenance, and repairs. Here is how these sectors leverage quantum computers.

**Artificial Intelligence (AI):**Researchers use quantum computing to analyze a wider range of algorithms and produce more accurate results than what traditional and supercomputers deliver.**Logistics:**Businesses can optimize operations by using quantum computing to suggest the fastest routes and provide real-time updates on weather conditions and traffic.**Drug development:**Pharmaceutical scientists can rely on quantum computing for disease research, solubility, dosing optimization, and safety evaluations to predict drug efficacy and toxicity levels.**Manufacturing:**Quantum computing can help smart factories plan more accurately and reduce expenses by assessing all the operations, automation processes, and technologies.**Maintenance and repairs:**Quantum technology can pinpoint software malfunctions and diagnose the best solution for efficient maintenance and repairs.

## In Closing

Quantum computers are much quicker than traditional and supercomputers, as they can process massive volumes of data simultaneously. The phenomena of superposition and entanglement, and qubits, allow quantum computers to solve complex challenges at rapid speed. Additionally, quantum computers are energy efficient and serve several applications, including manufacturing, drug development, logistics, and AI, to name a few. Overall, quantum computing is a powerful technology, but it is not practical for everyday tasks and inaccessible to the public.