Quantum Computing: Current Developments

Table of contents

1. What is quantum computing?
2. Fundamentals of quantum computing
3. Current trends and advances in quantum computing

What is quantum computing?

Quantum computing uses the principles of quantum mechanics to perform calculations exponentially faster than conventional computers. This means that quantum computers can simultaneously assume multiple states, which leads to an enormous degree of parallelism and solves complex problems more efficiently. This means that multiple calculations are processed simultaneously.

This technology opens up new possibilities in areas such as cryptography (encryption technology), materials science and machine learning, revolutionising the electronics and technology industry.

Fundamentals of quantum computing

• Qubits: Unlike conventional bits, quantum bits (qubits) can not only assume the states 0 and 1, but also superpositions of these categories.
• Superposition: This effect describes the ability of qubits to exist in multiple states simultaneously. When this phenomenon occurs, there is an enormous degree of parallelism, which allows quantum computers to perform many calculations at the same time.
• Entanglement: Qubits can be entangled with each other. This means that the state of one qubit is directly dependent on the state of another, regardless of the distance between them. This is a key resource for quantum computing, especially for algorithms such as quantum error correction and quantum teleportation.

Current trends and advances in quantum computing

The first quantum computer was born in 1990. However, unlike its first German successor in 2021, the model at that time only had a few qubits. This quantum computer, which was developed 31 years later by International Business Machines Corporation (IBM), was able to be put into operation with over 1000 qubits. IBM is still one of the leading players in quantum computing today.

Intensive research into quantum computers is also being conducted at Stanford University, the California Institute of Technology, the University of Tokyo and the University of Science and Technology of China. The findings obtained in this research must be constantly re-evaluated in order to sustainably change data processing. What you should know today:

Progress in hardware development

Thanks to the constant research and development of suitable hardware, the commercial use of quantum computers is now also making significant progress. For example, improvements have already been made to superconductors and photons, which leads to greater stability and performance. Quantum hardware is considered to be particularly promising in the fields of cybersecurity, pharmaceuticals, finance and modern manufacturing.

Another technical milestone: International Business Machines Corporation (IBM) has made significant advances in hardware development for quantum computers, in particular with the introduction of new processors and systems that significantly improve the scalability and performance of this technology. Of particular note are:

• IBM Quantum Heron Processor: The 133-qubit processor is characterised by a significantly reduced error rate and more power compared to previous models. It uses fixed-frequency qubits with tunable couplers, which results in a significant improvement in performance compared to the previous Eagle processor.
• IBM Quantum System Two: This modular system integrates multiple Heron processors and offers a flexible, expandable platform for quantum computing. It combines cryogenic infrastructure with third-generation control electronics and classic runtime servers. This system is designed to enable parallel quantum circuits, thus laying the foundation for quantum-centred supercomputing.

Public availability via cloud services

Even though the technology is not yet fully developed, quantum computers are no longer just a theory for the general public. What was long reserved for specialised physicists is now open to other users: writing quantum programs. This is made possible by cloud services and various open-source software environments.

The challenge of decoherence

Decoherence is one of the biggest problems in the field of quantum computing. It occurs when a quantum system interacts with its environment. Such phenomena arise, for example, due to thermal fluctuations , external electromagnetic fields or a material defect.

Such correlations cause the quantum mechanical properties to behave like classical states, which is why the advantages of quantum mechanics are lost. Quantum coherence can no longer be maintained and the unique quantum properties such as superposition and entanglement no longer exist.

The lifespan and reliability of qubits suffer considerably from this effect, which means that computers can only perform complex calculations with difficulty. Quantum computing can only be reliably realised once research has found valid methods to control and actively minimise decoherence.

Insufficient error correction

But it is not only decoherence that is an obstacle to progress in the development of quantum computers. These powerful computers are very prone to errors and conventional error correction methods from classical computer science cannot be applied directly to them.

The no-cloning theorem, which states that quantum information cannot be copied exactly without changing the original, also presents difficulties. Furthermore, the constant observation of the quantum system is disruptive. The implementation of quantum error correction requires many additional qubits and complex error correction codes, which makes scalability difficult.

Despite these major challenges, an efficient method of error correction must be found. It contributes to quality assurance and is therefore crucial for the progress and practical application of quantum computers.