1. August 2023 By Kevin Pahlke

# Unleashing the power of quantum computing: an inside look

#### An introduction to the world of quantum computers

Welcome to a fascinating topic that is redefining the boundaries of computer technology: quantum computing.

In a world where data is growing in both volume and complexity, quantum computers are opening up radical new possibilities for the future. In this post, we will explore the significance of quantum computing for science and the tech sector and look into why this topic is so interesting and important.

A standard computer today is based on bits that can have a value of either 0 or 1. Quantum computers, on the other hand, make use of the fascinating properties of quantum mechanics and work with quantum bits, also known as qubits. Unlike standard bits, a qubit can be in the 0 and 1 state at the same time thanks to a phenomenon called quantum superposition. Superposition enables quantum computers to perform complex calculations in a fraction of the time and complete tasks that would be impossible for conventional computers.

The transition from classical computers to quantum computers represents a revolution in computer technology. Quantum computers offer immense computing power and open up new possibilities for applications in a range of fields. From cryptography and data security to the optimisation of complex scenarios and simulations, quantum computers have the potential to revolutionise many areas of science and industry.

However, there are also challenges we face in the development and use of quantum computers:

- The technology is still in its infancy, and there are many obstacles to overcome.
- Error correction and noise in quantum computers are important aspects that require further research in order to develop reliable systems.
- Scalability is also an issue, since the number of qubits in quantum computers will have to be significantly increased to solve complex problems.

Nevertheless, the future looks promising for quantum computers. The technology is continuously evolving, and research institutions and private companies are investing in R&D in this field. New advances and developments in quantum technology suggest that quantum computers could soon become an integral part of our technological landscape.

In this blog post, I will look at the basics of quantum computers, their applications, their impact on society and future trends in the field. By understanding the potential of and challenges associated with quantum computing, you can prepare for an exciting future in which powerful computing systems push technological boundaries and open up new horizons.

#### From bits to qubits – the basics

To understand how quantum computers work, it is important to have a basic understanding of quantum mechanics, a fascinating field of physics that deals with the properties and behaviour of particles at the atomic and subatomic level.

A core concept of quantum mechanics is superposition. In contrast to classical physics, particles in a quantum mechanical state can be both 0 and 1 at the same time. This is made possible by superpositions, whereby particles exist in a state of uncertainty until a measurement is made and they are reduced to a defined state.

Another phenomenon in quantum mechanics is entanglement. Entangled particles are enigmatically linked, so that changes to one particle immediately affect the other particle, regardless of the distance between them. This phenomenon was referred to by Einstein as ‘spooky action at a distance’.

These properties of quantum mechanics form the basis for how quantum computers work. A qubit, the fundamental building block of quantum computers, can have the 0 and 1 states at the same time thanks to quantum superposition. By entangling qubits, quantum computers can process information in parallel and perform complex calculations in a fraction of the time it would take a conventional computer.

Quantum computers are currently very sensitive and can easily be disturbed by external influences. The noise caused by ambient temperatures and other factors can affect the stability of qubits and lead to calculation errors.

#### Error correction in quantum computers

Error correction is therefore a crucial aspect that must be considered in the development of reliable quantum computers. Due to the inherent sensitivity of qubits, they are prone to errors caused by various factors, such as ambient noise and imperfections in the hardware components. These errors can propagate and affect the accuracy of calculations, making it difficult to obtain reliable results.

To address this issue, researchers are actively working on developing error correction techniques for quantum computers. One approach is to encode qubits into larger quantum states called quantum error correcting codes. These codes distribute the information across multiple qubits in such a way that errors can be detected and corrected.

Quantum error correction involves the generation of redundant information by encoding qubits in a larger quantum state. By distributing the information across multiple physical qubits and carrying out operations on them, errors can be detected and corrected. This redundancy allows quantum computers to preserve the integrity of quantum information and mitigate the effects of errors.

However, implementing error correction in quantum computers is no simple task. It requires additional qubits and complex algorithms to perform error detection and correction operations. The overhead associated with error correction is considerable since a significant number of additional qubits are required compared to the original computing qubits.

In addition, the implementation of error correction in quantum computers must also take into account decoherence, i.e., the loss of quantum information over time. Decoherence is a significant obstacle to maintaining the stability of qubits and preserving their quantum states. To reduce decoherence, scientists are exploring techniques such as quantum error correction, fault-tolerant computing and error-avoiding quantum codes.

The development of robust error correction methods is an ongoing field of research in quantum information science. As technology advances, researchers are making progress in improving error correction techniques, reducing the impact of errors and increasing the reliability of quantum computers.

#### The path to high-performance quantum computers

Scalability is another significant challenge in the field of quantum computing. To solve complex problems and create practical applications, quantum computers must scale and have a large number of qubits. However, increasing the number of qubits is a complicated task.

Maintaining the coherence and stability of qubits becomes increasingly difficult as the number of qubits increase. The more qubits there are, the more susceptible the system is to noise and errors. In addition, the connections between the qubits, known as quantum gates, become more difficult to implement as the number of qubits increases.

Researchers and engineers are investigating a variety of approaches to solving scalability issues in quantum computing. One approach is to develop new technologies and materials that enable greater stability and coherence of the qubits. This includes advances in qubit fabrication, research into different qubit architectures (such as superconducting qubits, trapped ion qubits and topological qubits) and the development of error-resistant qubit designs.

Another research approach involves the development of fault-tolerant quantum computers that can work reliably even in the presence of errors. Fault-tolerant quantum computing involves implementing error correction techniques and quantum error-resistant codes to mitigate the effects of errors and ensure accurate calculations.

In addition, there is growing interest in hybrid models of quantum-classical computing. These models combine the strengths of classical and quantum computers to tackle complex problems. By using classical computing resources for error correction, optimisation and the traditional simulation of quantum systems, hybrid models should improve the scalability and reliability of quantum computers.

The path to scalable quantum computers is a complex and multidisciplinary endeavour that requires advances in materials science, quantum physics, computer architecture and error correction techniques. However, with ongoing research and technological advances, the goal of powerful and scalable quantum computers is within reach.

#### Applications and implications of quantum computing

Quantum computers have the potential to revolutionise a host of fields and industries. The immense computing power of quantum computers can facilitate breakthroughs in solving complex optimisation problems, simulating quantum systems and improving cryptography.

Here are just a few of the potential applications for quantum computing:

**Optimisation:** Quantum computers can efficiently solve optimisation problems that have broad applications in areas such as logistics, supply chain management and finance. Quantum algorithms, such as the quantum approximate optimisation algorithm (QAOA) and the quantum fourier transform (QFT), offer the potential to significantally reduce the time required to solve optimisation problems.

**Simulation of quantum systems:** Quantum computers can simulate quantum systems more accurately than classical computers. This has applications in areas such as materials science, drug discovery and understanding chemical reactions at a fundamental level. The simulation of quantum systems can provide insights into complex phenomena that are difficult to investigate using classical computational methods.

**Cryptography:** Quantum computers have the potential to impact cryptography by breaking certain asymmetric encryption algorithms such as RSA and ECC, which rely on the difficulty of factorising large numbers. Quantum algorithms such as Shor’s algorithm can efficiently factorise large numbers, making these cryptographic methods vulnerable to attack. However, research is also underway to develop quantum-resistant encryption algorithms that can withstand attacks from quantum computers.

**Machine learning:** Quantum machine learning is an emerging field that focuses on the interface of quantum computing and classical machine learning. Quantum computers have the potential to improve machine learning by processing and analysing large data sets more efficiently or using quantum mechanical principles to develop new learning algorithms.

**Quantum chemistry:** Quantum computers can revolutionise computational chemistry by enabling more accurate simulations of molecular systems. This has implications for drug development, materials science and the understanding of complex chemical reactions. Quantum computers can tackle problems that are computationally intractable for classical computers, enabling more precise modelling and prediction.

These are just a few examples of the many potential areas where quantum computing can be used. As technology progresses and quantum computers become more powerful and reliable, their applications will continue to grow and facilitate transformative changes in a range of industries and scientific disciplines.

#### The new era of quantum computers – where we now stand

Quantum computing opens up considerable opportunities while also presenting a number of challenges. Overcoming the challenges of error correction and scalability is crucial for the development of practical and reliable quantum computers. While scientists and engineers are making progress in these areas, quantum computing has the potential to revolutionise applications and fields such as optimisation, simulation, cryptography, machine learning and quantum chemistry. Exciting advances are on the horizon, with quantum computing on the verge of reshaping our technological landscape in the future.

Would you like to learn more about exciting topics from the adesso world? Then take a look at our blog posts that have appeared so far.