Quantum computing is a cutting-edge technology gaining much attention in the media. It’s part of the second quantum revolution and is characterized by quantum bits (qubits) as the smallest unit of information, which differ from the bits used in regular computers. Qubits can be in a state of one, zero, or both simultaneously, which allows for incredibly fast and parallel calculations. This means that a quantum computer can evaluate many states simultaneously and find the right solution to a problem from billions of possible solutions with just one call.

In the last few years, quantum computing has become more prominent in the industry, with established tech companies and start-ups investing in research and development. One of the main motivations behind quantum computing is the simulation of quantum mechanics, which is a complex problem that regular computers can’t handle efficiently. Quantum computers can perform simulations and calculations that classical computers can’t, making them incredibly powerful for specific applications.

Like regular classical computers, quantum computers have processors that perform operations and calculations. Still, unlike classical bits of information, their qubits are directly connected to the underlying physics and can be implemented via electrons, for example, which means that they can be in a superposition state of 0 and 1 and use entanglement, which allows for correlating multiple or all qubits in a system. Changing one qubit can affect all other qubits without additional computational effort, which makes quantum computers extremely powerful.

Although it’s difficult to show useful quantum supremacy, which is when a quantum computer can compute something practically useful that a classical computer can’t in a finite time, the industry can still benefit from the speed, precision, and cost-effectiveness of quantum computing. Even a few minutes gained in processing time or a few percent in increased quality of a solution can make a significant difference in some applications, such as traffic flow optimization. Many of the algorithms developed today will generalize and scale to future systems, making quantum computing a wise investment today.

These are sensors that use quantum properties to detect and measure physical phenomena such as magnetic fields, electric fields, and temperature. Quantum sensing is an exciting and growing field that is less well-known than quantum communication and quantum computing.

It involves using quantum states to make incredibly precise measurements of motion, electric and magnetic fields, and imaging. Quantum states are very sensitive to disturbances, which means they can be used to create highly accurate measuring instruments. While measuring devices that use quantum properties have been around for a long time, the second quantum revolution is seeing individual quantum systems, such as atoms and photons, being used as measuring probes. We can increase sensitivity beyond what was previously thought possible by entangling and manipulating these quantum states. One of the main advantages of quantum sensing compared to purely classical sensors is its extreme precision.

For example, atomic clocks use electrons in different energy states to measure time accurately. Other quantum sensors can measure tiny changes in motion, gravity, and electric and magnetic fields. This has enormous practical implications for a wide range of fields, from navigation and detecting changes in climate and volcanic activity to improving medical technology such as brain-machine interfaces and medical imaging.

Quantum sensors will revolutionize everyday life, securing navigation, revealing what is hidden deep underground, and detecting early warning signs for earthquakes and volcanic eruptions. The development of quantum sensors will lead to more powerful instruments for measuring electric and magnetic fields in our environment and bodies. We will be able to measure local variations in gravity to find minerals, water, or pipelines embedded underground. The possibilities extend beyond research activities to practical applications in everyday life.

These are devices that use quantum properties to encrypt and transmit information in a secure and un-hackable way. Quantum communication is a rapidly advancing field that has the potential to revolutionize the way we communicate and transmit data securely. It is a subfield of quantum information science that exploits the principles of quantum mechanics to develop secure communication protocols and systems. The basic idea of quantum communication is to use the unique properties of quantum particles, such as photons, to transmit information between two parties in a way that is impossible to intercept or eavesdrop on.

The key features of quantum particles that make them useful for communication are their quantum states, which can be used to represent information securely and reliably. The most well-developed quantum communication technologies to date are Quantum Key Distribution (QKD) and Quantum Random Number Generators (QRNG). QKD enables two parties to generate a shared secret key that can be used for secure communication, while QRNGs provide a source of truly random numbers, which are essential for encryption and other security applications.

QKD protocols typically involve the exchange of photons that carry information in their quantum states, such as their polarization. By measuring the polarization of the photons, the two parties can establish a shared secret key known only to them. Any attempt to intercept or measure the photons in transit would disturb their quantum states and therefore be detected by the communicating parties. This makes QKD protocols resistant to eavesdropping attacks and provides a high level of security for communication. QRNGs, on the other hand, generate random numbers based on the inherent randomness of quantum mechanics. The non-deterministic nature of quantum theory ensures that only truly random numbers can be generated with it.

As a result, QRNGs are becoming increasingly important in many applications, such as cryptography, gaming, and even securing our infrastructure, such as energy grids. While QKD and QRNGs are the most mature technologies in quantum communication, there are also other applications beyond the distribution of secret keys. For example, quantum communication could be used for secure teleconferencing, cloud computing, and voting systems, among other applications. However, the development of a quantum communication network, or the quantum internet, is still in its early stages. The future holds even more potential, but also more challenges. The development of more complex systems based on and exploiting entanglement will allow quantum resources such as qubits, entanglement, and the inherent randomness of quantum physics to be distributed over large distances as the basis for a quantum internet.

These are devices that use quantum properties to make highly accurate measurements of physical quantities such as time, distance, and mass. In our modern world, precision measurement is an essential tool for scientific discovery, technological innovation, and everyday life. We rely on accurate measurements for a wide range of applications, from building bridges and highways, to monitoring the Earth’s climate and exploring the universe.

The field of metrology, which is the science of measurement, has made great strides over the past few decades thanks to the development of quantum mechanics. The principles of quantum mechanics are now being applied to metrology, leading to the development of quantum metrology. Quantum metrology is a subfield that uses quantum systems’ properties to make more accurate measurements. In particular, quantum metrology exploits the phenomenon of quantum entanglement, which is the phenomenon where two particles can become correlated in such a way that their states are no longer independent of each other.

The development of quantum metrology can revolutionize many fields of science and technology. For example, it could lead to the development of more accurate medical imaging techniques, such as magnetic resonance imaging (MRI). MRI works by measuring the magnetic fields produced by the body’s tissues, and quantum sensors could make these measurements much more precise, leading to earlier and more accurate diagnoses. Quantum metrology could also lead to the development of more efficient and sustainable energy technologies. For example, it could be used to create sensors for monitoring and optimizing the performance of wind turbines, solar panels, and other renewable energy sources. It could also be used to develop more efficient batteries and fuel cells, which are essential for the transition to a low-carbon economy. The development of quantum metrology is a major breakthrough in the field of precision measurement.

By harnessing quantum effects, we can create new and more accurate measurement devices that have the potential to transform many fields of science and technology. As we continue to explore the world of quantum mechanics, we expect even more exciting developments in the field of quantum metrology in the years to come.

These are devices that use quantum properties to simulate the behavior of complex systems, such as chemical reactions or materials at the atomic scale. In 1982, Richard Feynman gave a visionary talk entitled “Simulating Physics with Computers” in which he proposed the idea of quantum simulators. Feynman emphasized the impossibility of simulating a quantum mechanical system with a classical computer, noting that even describing the entire quantum state of around 60 electron spins is beyond current computing capabilities. Instead, Feynman proposed that a quantum system could be simulated over another quantum system, which would be easier to control and study, making the simulation more efficient and feasible.

To understand complex molecules, quantum interactions between their components must be understood and modeled. However, classical computers struggle to master quantum mechanics, regardless of their computing power and storage volume. Quantum simulators, on the other hand, can perform computer simulations for these problems much more efficiently. This is because quantum simulators don’t need to be taught quantum mechanics – they already work by the same rules.

One area of application for quantum simulators is medicine and pharmacology. Alzheimer’s, Parkinson’s, and Huntington’s are diseases caused by incorrectly folded protein molecules. Quantum simulations will help us to understand protein folding at the smallest, quantum physical level and to develop treatments to cure these diseases. Another application of quantum simulators is in high-temperature superconductivity. Currently, the loss in power transmission is up to 10% of electrical power.

Superconductors can transmit electrical currents without loss, but the superconductors available today only work at temperatures below -100°C. Quantum simulations will be crucial for developing high-temperature superconductors which can transmit electricity from power plants without any loss. Understanding the precise quantum dynamics of chemical reactions can also benefit our environment. For example, quantum simulators can help identify chemical catalysts to remove CO2 from the atmosphere or reduce the energy we currently need to produce fertilizers. Feynman’s idea of quantum simulators has opened up new doors in scientific research and has the potential to revolutionize various fields, from medicine and pharmacology to environmental sustainability. By harnessing the power of quantum mechanics, we can gain deeper insights into the natural world and use that knowledge to improve our lives.