Quantum Wiki
The world of quantum physics is full of fascinating phenomena—from superposition and entanglement to entanglement and wave-particle duality.
This wiki provides explanations of key concepts, terms, and technical expressions from the world of quantum physics.
Quantum Terms
Communication
Communication
The term communication comes from the Latin communicatio and means message. Communication describes the process of transmitting information—between people, animals, machines, or even cells.
Measurement of a quantum system
Measurement of a quantum system
The measurement of a quantum system is a decisive moment in quantum physics. In this process, a quantum particle—such as an electron or photon—is observed or measured, and this process forces the system to assume one of two possible basic states. This so-called projection is the only way to obtain information about the particle.
Before measurement, the particle can be in a superposition, i.e., in several states at the same time. But at the moment of measurement, the system assumes a specific state—and the original superposition state is irrevocably lost.
This behavior can be compared to a kaleidoscope: once turned, it shows a completely new pattern that cannot be exactly reproduced. Similarly, the state of a quantum system cannot be reproduced after measurement.
No-Cloning-Theorem
No-Cloning-Theorem
The no-cloning theorem states that it is impossible to produce an exact copy of an unknown quantum state.
This fundamental property of quantum physics ensures that information in quantum communication systems is particularly secure—because it is impossible to eavesdrop on or copy quantum information without altering it.
NV Center
NV Center
An NV center (nitrogen-vacancy center) is a special crystal defect in the diamond lattice in which a carbon atom is replaced by a nitrogen atom and at the same time there is an adjacent vacancy in the crystal. This defect center is one of over 100 known defects in diamonds and plays an important role in quantum physics, for example in quantum computers and sensors.
Superposition
Superposition
Superposition is a central concept in quantum mechanics. It describes how a quantum object—such as an electron, photon, or qubit in a quantum computer—can exist in multiple states simultaneously. A qubit can therefore be 0 and 1 at the same time. Only when measured does the qubit assume one of the two states (0 or 1), thereby destroying the superposition state.
A vivid example is a spinning coin: as long as it is in the air, it is both heads and tails at the same time—only when it falls to the ground does it show one of the two sides. The same is true for a quantum particle in superposition.
This principle enables the enormous power of quantum computers, as they can perform many calculations in parallel.
The concept became famous through Schrödinger’s cat thought experiment, which illustrates that a system in the quantum realm can exist in multiple states simultaneously—as long as it is not measured.
Entanglement
Entanglement
Entanglement is a fascinating phenomenon in quantum physics in which two particles are connected in such a way that their possible states correlate with each other in a special way.
This correlation only becomes apparent when a measurement is taken: if one of the two particles–regardless of how far apart they are–shows a certain measurement result, then the result of the other is clearly linked to it. Entanglement does not describe remote influence, but rather a profound statistical dependence that forms an important basis for modern quantum technologies.
Entanglement is therefore a connection (correlation) between the superposition of two qubits. Let’s assume that the two qubits are two coins. When the two qubits are measured, it is as if the two coins were tossed. Without entanglement, the coins show heads or tails independently of each other. If you create a table and repeat the experiment, you will see that all possible outcomes are equally likely. However, if the coins were entangled and you performed the same experiment, you would find that when one coin shows heads, the other also shows heads, and vice versa. The event “coin 1 = heads” and “coin 2 = tails” therefore never occurs. And this is independent of how far apart the coins are from each other.
This strong connection is not only an amazing natural phenomenon, but also an important basis for modern technologies such as quantum computers and quantum communication.
Wave-Particle Duality
Wave-Particle Duality
Wave-particle duality describes a central phenomenon in quantum physics: quanta—tiny particles such as light (photons) or electrons—exhibit properties of both particles and waves.
Depending on how they are observed or measured, they sometimes behave like small, point-like particles and sometimes like spreading waves. This seemingly contradictory behavior can only be explained by the laws of quantum mechanics and shows that the world at the smallest level functions very differently from how we experience it in everyday life.
Quant
Quant
A quantum is the smallest, indivisible unit of a physical quantity—the “minimum package” of nature, so to speak. Energy, light, and even matter do not occur continuously, but in tiny portions called quanta.
A well-known example is the photon, which is considered a quantum of light. Electrons are also quanta – tiny particles that behave both like particles and like waves. This seemingly contradictory behavior is called wave-particle duality.
Quantum mechanics describes how these smallest units behave with its rules and theories – and thus forms the basis for many modern technologies, from lasers and computer chips to quantum computers.
Quantum computer
Quantum Computer
A quantum computer does not process information like classical computers with bits, but with qubits, which can occupy multiple states simultaneously–comparable to a dimmer switch that allows for continuously variable light intensities. Our NV-center–based quantum computers manipulate the energy states of electron spins and measure them based on their photon statistics. To control these complex processes, quantum computers consist of various components such as signal sources, lasers, and controllers. Thanks to this technology, they can solve highly complex problems exponentially faster, especially when dealing with large data sets, probabilistic results, or optimization tasks. Quantum computing is thus a fundamentally new approach to data processing.
Quantum computing
Quantum Computing
An innovative computing approach that uses qubits instead of traditional bits. These are based on the principles of quantum mechanics and allow complex calculations to be performed much faster than conventional computers. Quantum computers use effects such as superposition and entanglement to solve tasks that often take exponentially longer for classical systems.
Quantum Communication
Quantum Communication
An advanced technology for secure data transmission that uses quantum physics principles such as entanglement and superposition. Protocols such as E91 and BB84 enable the exchange of keys for encrypted communication, with security based on physical laws rather than mathematical assumptions. Quantum communication immediately detects eavesdropping attempts, thus protecting the confidentiality of information–even against future attacks by quantum computers. Due to technical challenges in transmitting unstable quantum states, it is currently most relevant in security-critical areas such as public administration, defense, healthcare, and the financial sector. It complements existing encryption methods and represents a future-proof security layer.
Quantum-Tunneling
Quantum Tunneling
Quantum tunneling describes a fascinating phenomenon in which a quantum –for example, an electron– can pass through a barrier even though it does not actually have enough energy to overcome it in the conventional way.
This works because quantum particles behave not only like particles, but also like waves. This means that they have different probabilities of being in different places at the same time–even on the other side of a seemingly impenetrable barrier.
This principle is not just a theoretical peculiarity, but plays an important role in nature: for example, quantum tunneling enables hydrogen atoms to fuse in nuclear fusion, releasing sunlight.
Qubit – Quantum Bit
Qubit
A qubit is the smallest unit of information in a quantum computer – comparable to the bit in conventional computers. However, while a classical bit can only be 0 or 1, a qubit can assume both states simultaneously. This special behavior is called superposition.
In a figurative sense, this can be imagined as follows: A classical light bulb is either off (0) or on (1). A qubit, on the other hand, would be like a light bulb that is both off and on at the same time – until it is measured. Only through measurement does the qubit assume one of the two states.
Physically, a qubit can be a quantum particle or a quantum system that naturally has two states—for example, the spin of an electron, the polarization of a photon, or the energy levels of an atom. Quantum information is processed by specifically manipulating and measuring these particles.
Beat the Quantum Randomness
Human vs. Quantum computer
How random can you type a row of fifty 0 and 1? Is your input more random than the output of a quantum computer? Give it a try and learn more about the way a quantum computer works!
Application of Qunatum Comminaction
Random Numbers
Random Numbers
Many modern security systems and websites rely on quantum randomness to generate encryption keys that are truly unpredictable. These genuine random numbers form the basis for even stronger IT security.
Quantum Cryptography
Quantum Cryptography
Quantum cryptography enables secure key exchange based on the physical laws of quantum mechanics—not on an attacker’s computing power. A well-known example is the BB84 protocol. A major advantage is that any attempt at eavesdropping can be detected immediately, guaranteeing the confidentiality of communications.
Tap-proof networks
Tap-proof networks
The development of so-called “quantum internet” structures is laying the foundation for highly secure communication between government agencies, banks, companies, and critical infrastructure. Initial pilot projects in China and Europe are showing promising results. Absolutely tap-proof communication is particularly important in areas such as the military, research, healthcare (e.g., patient data), and even in everyday life.
Satellite Communications
Satellite Communications
Quantum key distribution via satellites is used to bridge large distances where fiber optic connections reach their limits. A well-known example is the Chinese “Micius” satellite, which enables quantum communication between China and Vienna.
Quantum repeaters & networks
Quantum repeaters & networks
Application of Qunatum Technology
Medicine
Medicine
Modern imaging technologies such as magnetic resonance imaging (MRI) are based on principles of quantum physics. They use nuclear spin and quantum alignment to generate high-resolution images from inside the body—a fascinating application of quantum mechanics in healthcare.
Big data analysis
Big data analysis
Quantencomputer können bestimmte Rechenoperationen, beispielsweise in der linearen Algebra oder Mustererkennung, exponentiell schneller ausführen als klassische Systeme. Das eröffnet vielfältige Einsatzmöglichkeiten in Bereichen wie Bild- und Spracherkennung, Finanzmarktanalysen oder medizinischen Diagnosen. Viele Big-Data-Herausforderungen sind Optimierungsprobleme, etwa in der Routenplanung oder Ressourcenverteilung – hier könnten Quantenalgorithmen innovative Lösungen liefern.
Materials research
Materials research
Quantum mechanics is fundamental to understanding materials.
Classical computer simulations often reach their limits because the interactions of many electrons are extremely complex. Quantum computers and special algorithms offer new possibilities: they enable the simulation of new materials, the calculation of electronic structures of molecules and solids, and the development of advanced technologies such as superconductors, battery materials, semiconductors, and topological quantum materials.
Laser technology
Laser technology
Light from LEDs and lasers is produced by electrons jumping between energy states – a process that can only be explained by quantum mechanics Light from LEDs and lasers is produced by electrons jumping between different energy states – a process that can only be explained by quantum mechanics. These fundamentals enable numerous applications in communication, medicine, and industry.
Quantum Education
SCHOOL MODULE Q1
.
Be part of the quantum future
We offer various educational and cooperation formats that impart knowledge and promote exchange between science and industry.
INDUSTRIAL INNOVATION DAY
.
SCHOOL MODULE Q1
.