Glossary

Quantum Technology
Quantum technology encompasses a broad range of technologies that leverage the principles of quantum mechanics to develop innovative applications in various fields. These technologies exploit quantum phenomena, such as superposition and entanglement, to achieve unprecedented levels of computational power. Examples of quantum technologies include quantum computing, quantum communication, quantum sensing, and quantum cryptography. Quantum technology holds the potential to revolutionise industries ranging from healthcare and cybersecurity to materials science and telecommunications, promising profound advancements in capabilities and performance.

Quantum Mechanics
Quantum mechanics refers to material objects and models them as individual particles or as systems consisting of a certain number of individual particles. These models can be used to describe elementary particles, atoms, molecules or macroscopic matter in detail.

Quantum Computing
Quantum computing is a rapidly advancing area of research that harnesses the principles of quantum mechanics to perform computational tasks in fundamentally new ways. Unlike classical computers, which use bits as basic units of information (0 or 1), quantum computers employ quantum bits, or qubits, which can exist in superposition states, representing both 0 and 1 simultaneously. This allows quantum computers to perform parallel computations on a massive scale, potentially solving certain problems much faster than classical computers. Quantum computing has the potential to revolutionise fields such as cryptography, optimisation, and materials science. However, building and operating practical quantum computers remains a significant technological challenge, and the field is still in its early stages of development.

Quantum Computer
Quantum computers are computing devices that run on the principles of quantum mechanics. In contrast to the classic computer, it does not work on the basis of binary states of electronic circuits, but on quantum mechanical states of quantum bits or qubits, which can exist in different states at the same time. Quantum computers operate at extremely low temperatures (approx. -270°C), to prevent interference and to maintain the delicate quantum states required for computation. Currently, there are only a few quantum computers that are operational, most of which have been built by research institutions and technology companies (e.g. IBM or Google). These quantum computers are often accessed via cloud-based services. However, the field is rapidly advancing, with large investments from both the public and private sectors, which will likely increase the number of quantum computers in the coming years.

Quantum Bits (Qubits)
In the realm of quantum computing, qubits serve as the basic units of information. In contrast to the binary codes of a conventional computer, which operates with 0 or 1, qubits possess the remarkable ability to exist in a state of superposition, meaning they can simultaneously represent both 0 and 1. Additionally, qubits can be entangled, forming interconnected relationships with other qubits that offer computational advantages. However, maintaining the delicate quantum states of qubits presents significant challenges, including interference from their surroundings, which can disrupt computations. Despite these hurdles, ongoing research endeavors to strive to overcome these obstacles and harness the potential of quantum computing.

Quantum Measurement
Quantum measurement is the process of observing and obtaining information about quantum systems, such as particles or qubits, which are governed by the principles of quantum mechanics. In quantum mechanics, measurements are inherently probabilistic, meaning that they provide only probabilistic outcomes rather than definite results. Additionally, the act of measurement can disturb the quantum state of the system being measured, altering its properties in unpredictable ways. Quantum measurement plays a crucial role in understanding and characterising quantum systems, as it allows scientists to extract valuable information about their states and behavior. However, the subtleties of quantum measurement pose significant challenges, particularly in maintaining quantum phenomena like superposition and entanglement.

Entanglement
In quantum physics, entanglement is a peculiar phenomenon where the properties of two or more particles become intertwined in such a way that the state of one particle is immediately correlated with the state of another, irrespective of the spatial separation between them. This means that changes made to one particle are reflected in the other, creating a mysterious and instantaneous connection between them. For instance, if two particles are entangled and one is measured, determining its state will instantly reveal the state of the other particle, regardless of the physical distance between them. Entanglement is a fundamental aspect of quantum mechanics and remains a subject of intense theoretical and experimental investigation.

Superposition
In quantum mechanics, superposition is a fundamental principle that describes the state of a particle, such as an electron, as existing in multiple states simultaneously. This means that until a measurement is made, the particle doesn’t have a definite position or properties. It’s akin to a spinning coin that seemingly defies landing on either heads or tails until observed. Superposition is not just a theoretical concept; it's crucial for understanding quantum systems and is a fundamental building block for quantum computing. In quantum computing, the ability of quantum bits (qubits) to exist in superposition states allows for parallel computation, enabling quantum computers to perform certain tasks exponentially faster than regular computers that use binary processors.