The foundations of quantum physics were developed in the first half of the 20th century. These early discoveries include the quantization of light, the uncertainty principle, and wave-particle duality. Other discoveries from quantum mechanics include the tunneling effect of electrons and giant magnetoresistance (GMR). Without the tunnel effect, electronic devices such as transistors and diodes in the field of semiconductor technology cannot be realized. The GMR effect is used to store data on HDD hard disks. In medical technology (MRI), the spin effect of atomic nuclei is used to generate images of the inside of a body.
These technologies are based on the quantum mechanical effects of a variety of quantum particles such as electrons or the coherence of photons in lasers. This is also called the first quantum revolution.
The targeted manipulation, measurement and control of individual quantum particles, on the other hand, is the subject of the so-called second quantum revolution. This is based on seemingly mysterious quantum mechanical phenomena such as quantum entanglement and quantum teleportation. One of the most significant areas of this revolution, which is the subject of current research and development, is the quantum computer. Its computational power will far exceed that of currently used supercomputers, enabling, among other things, more accurate weather forecasts and facilitating the decoding of large molecular structures. The no-cloning theorem is another quantum phenomenon that is used, among other things, to realize a tap-proof encrypted connection on the Internet.