Applications of quantum mechanics in real world
In the previous article, I have discussed about the applications of quantum mechanics in Science. Now, we are going to learn about the applications of quantum mechanics in technology. You may ask, how this type of imagined stuff will be applicable in our daily lives? Well, quantum mechanics filled with scientific jargons and complex maths, but its practical applications are enormous. Below are some of the usages of quantum mechanics in our lives!
Quantum random number generator
We come across dice rolling and computer softwares that generate random numbers when we execute them. However, scientists argue that these methods can ultimately be predicted if we are able to crack the softwares and if we are able to study every physical feature of the dice before we roll it. Theoretically, scientists regarded numbers generated by quantum random number generator as truly random because the generator produce a series of numbers based on photoelectric effect (production of electrons after high frequency electromagnetic radiation absorption by certain metals) and quantum noise (uncertainty of some physical quantity due to its quantum origin) which are the natural sources of signals.
This mechanism is able to generate random numbers to encrypt data and to use weather simulators. Do remember random numbers is necessary to select a sample which is bias-free.
Transistors and semiconductors
The quantum tunneling phenomenon applicable in transistors too. Electrons can absorb energy from the surrounding colliding particles and break the barriers that impede their movements. When the barrier breaks, the electrons produce a current that varies exponentially with the electrical field applied. This will open and close the logic gates which are essential for the operations of the computers.
Diodes work based on the principle of voltage bias. This means that there is a higher current in one direction than the other. By applying the concept of quantum tunneling, the diode will be able to work faster.
Some useful books on quantum mechanics
For quantum mechanics lovers out there, this is the book explains quantum mechanics in layman terms with minimum of mathematics and maximum of analogy.
This book offers fascinating overview of controversial quantum theories and is suitable for people with little scientific or mathematical background.
A book for students studying quantum mechanics so that they can explore the quantum paradoxes in greater detail.
Scanning tunneling microscope
This is the only microscope that can visualize atoms as fuzzy balls. A needle with a voltage bias bought close to the surface of the sample. Some electrons are able to jump from the sample to the tip by quantum tunneling. By measuring the current between the needle and the surface of the sample, the distance between the two are also measured. This data is then fed into a processor to display as an image.
As discussed from the previous article, the electrons will emit energy in the form of electromagnetic waves when fell from higher energy levels to the lower ones. The electromagnetic waves visualized as different colours of lights. This is achieved by heating a certain gases in the discharge tube. For example, neon gases gives red coloured light while Krypton gives white coloured lights. This is the working principle of colourful fluorescent lights on the streets.
While for lasers, the working principle is the same as fluorescent lights except that there is a large numbers of simultaneous falls of electrons from higher energy levels to the lower ones, which gives a very strong beam of light which can aim at a particular direction. By stimulating an electron with a certain frequency of light; the above requirements are achieved. This process is known as stimulated emission. Lasers are essential in reading CDs and DVDs.
Magnetic Resonance Imaging (MRI)
MRI works because of manipulation of a quantum-mechanical phenomenon called particle 'spin' inside the human body. Large planetary bodies such as earth have angular momentum and magnetic fields because they spin on their axis. Particles such as the nuclei of an atom also have angular momentum and magnetic moments, but they do not actually spinning themselves. However, the physicist decided to call them 'spin' anyway. The magnetic fields produced by the atomic nuclei in the human body are detected and then displayed as an image.
Improving atomic clocks
Atomic clocks are known as the world's most accurate clock that can have an accuracy of 10−9 seconds per day. Such accuracy is essential to control the wave frequencies of television broadcasts. Besides, it is also essential for GPS tracking system. The inaccuracy of atomic clocks may lie on the phenomenon called quantum noise. Quantum noise disturbs vibration measurements of Caesium atoms. However, by manipulating the energy states of the Caesium atoms, it can suppress the noise levels and thus improving the accuracy of the atomic clocks.
We all know that electron is a particle that revolves around the nucleus of an atom. However, introduction of quantum mechanics changes such perception. Quantum mechanics introduced a term called "particle-wave duality" which means that a particle/wave can behave like a particle and like a wave at the same time. The same applies to light where light can behave like a light wave or as photon particle that carries light energy. Light microscope uses light waves as a medium of transmission and wavelength of light determines the highest resolution of a microscope which is 200 nanometres. While for electron microscope, electron waves can meet highest possible resolution of 20 picometres due to its shorter wavelength. Therefore, electron microscope is able to visualize viruses which is an impossible feat in case of light microscopy.