Quantum Technologies
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Audio Chapter 1:
Welcome to this first chapter of the first module of the Quantum Communication Course. In this course, we will deepen our knowledge regarding quantum communication. This happens on a rather qualitative level; in this course, we try to avoid formulas or other mathematical details. In terms of content, we will discuss cryptography, discuss various cryptographic protocols, discuss the possible application fields of quantum communication. But what exactly is quantum communication? What is quantum communication based on? How does it differ from normal communication?
Quantum physics
In this first module, we start from the beginning: quantum physics. Quantum physics is a fundamental theory of physics. It provides a description of the physical properties at atomic and subatomic scales. Developed in the early 20th century, quantum physics fundamentally changed our understanding of the microworld. It explained phenomena that could not be explained by classical physics. Quantum physics introduces concepts that defy our classical intuition. One such example is the wave-particle duality, which describes how electrons can exhibit wave-like and particle-like properties. Therefore, it seems incorrect to refer to the electron as a particle, since an electron can also display wave-like properties under certain circumstances. Similarly, it seems incorrect to refer to the electron as a wave, since an electron can also display particle-like properties under certain circumstances. For this reason, we will henceforth refer to them as quantum objects rather than waves or particles.
In addition to the wave-particle duality, quantum objects also exhibit other remarkable, even fascinating phenomena. For instance, quantum objects can exist in superposition states and simultaneously describe possible states – until the measurement is done. Or they can be entangled and influence each other mutually. Detailed explanations about these phenomena will be provided in the following chapters and modules!
First-generation quantum technologies
In the 20th century, quantum technologies of the first generation were developed. Researchers engaged with quantum physics and began to understand and apply the basic rules of quantum physics. This era concluded with the development of technologies crucial for modern electronics and telecommunications; for instance transistors and lasers.
The invention of the transistor revolutionized electronics. It enabled the manufacture of smaller and more efficient circuits.
By contrast, lasers are used in many fields – from medicine to communication technologies. They also rely on quantum physical phenomena – the controlled stimulation of emissions.
These advancements mark the beginning of a new era; an era that transformed the industry and paved the way to the digital age.
Second-generation quantum technologies
The era nowadays focuses on the development of quantum technologies of the second generation. In this era, it is mainly about developing technologies that explicitly leverage quantum physical phenomena. Contrary to the quantum technologies of the first generation, quantum technologies of the second generation explicitly uses phenomena like superposition, entanglement and quantum tunnel effects, to create transformative technologies.
Whenever we are speaking, describing or explaining quantum technologies, we mean everytime – really everytime – quantum technologies of the second generation. These technologies can be subdivided into four pillars: quantum computing, quantum communication, quantum sensing and quantum simulation. Technologies of these pillars should help to revolutionize the industry and everyday life in such a way, we cannot foresee right now. Let’s have a deeper look at these four technological pillars:
Quantum computer
Quantum computers leverage the principles of superposition and entanglement to solve complex, high-dimensional problems. In this context, it is expected that quantum computers will be able to solve specific, tailored problems faster and more efficiently than classical computers. Classical computers use bits as the smallest unit of data. One bit can have the value of 0 or 1. In contrast, quantum computers use quantum bits, also known as qubits. One qubit is able to be in a superposition state of the states of 0 and 1. This enables them to simultaneously process enourmous amounts of possible states. Quantum computers have the potential to revolutionize fields such as cryptography, where they can break current encryption methods. They have the potential to revolutionize fields such as materials science, where they can simulate complex molecular structures to discover new materials and drugs.
Quantum communication
Quantum communication uses quantum phenomena to enhance the security and efficiency of information transmission. One of the most-promising applications of quantum communication is the quantum key distribution, in short QKD. QKD enables two communication parties to produce a shared, random security key, which is only known by them. This key can be used to encrypt and decrypt messages as well as data in general. The encrypted messages are immune to eavesdropping. The security of QKD is based on fundamental rules of physics. Any possible eavesdropping attack will disturb the quantum state, leading to both parties noticing the eavesdropper. This makes QKD a strong tool for secure communication in an increasingly digitalized world.
Quantum sensor
Quantum sensors improve the precision of measurements. They utilize those states of the matter that react highly sensitively to environmental changes. This is how quantum sensors manage, for instance, to measure gravitational fields with unprecedented precision. This is how quantum sensors manage, for instance, to detect small magnetic fields. This is how quantum sensors manage, for instance, to ascertain changes of temperature in the nanometer range. These advancements can lead to more accurate diagnoses in medicine, for instance by enhanced MRT machines. They can lead to better environmental monitoring – for instance by detecting smallest changes of Earth’s magnetic field or the identification of underground resources without drilling. Quantum sensors leverage phenomena like superposition and entanglement to reach sensitivities far beyond classical sensors. Thereby, new opportunities for scientific discoveries and technological innovation are revealed.
Quantum simulation
Quantum simulation utilizes quantum computers to model the behaviour of matter on an atomic and subatomic level. This approach can lead to breakthroughs in materials science, chemistry and pharmaceutical research, because quantum simulation is able to predict properties of materials and molecules more exactly than classical simulations. For instance the simulation of the behaviour of complex molecules and chemical reactions can therefor help to design new pharmaceuticals. It can help to design materials with specific, desired properties. Additionally, quantum simulations could provide insights into fundamental processes of physics – for instance superconductivity. They could contribute to the development of lossless electrical grids and further advanced technologies. Through the imitation of the quantum nature of systems, quantum simulations provide a powerful tool to investigate the boundaries of science.
Implications
The implications of quantum technologies are vast. Quantum technologies have the potential to transform industrial sectors – from cybersecurity to pharma industry. They have the potential to provide capabilities beyond the possibilities of classical technologies. The future of quantum technologies holds a lot of potential, significantly enhancing the computational power, securing communication networks and advancing the performance of sensors. All these will conclude profound effects on society and industry.
Structure of the course
In this course, we will focus on quantum communication and during this will engage with different aspects. First of all we have a look at QKD and examine protocols to implement a secure key exchange. Subsequently, we will explore quantum networks as well as associated fundamental basics and concepts for future implementation. Lastly we address explicit industrial sectors. Here we will explore how quantum communication as well as terms discussed up until then could transform the industry or may already transformed the industry. Follow us on this journey through the world of quantum communication. A world providing secure data transmission; a world ensuring sensitive information; a world that does not resemble the classical, familiar world we know.