If we look at water, we can easily observe the spontaneous change of the substance: at 100 degrees Celsius it evaporates into gas, and at 0 degrees Celsius it freezes into ice.

The laws of nature and nature are hidden in the dark;

God said, let Newton go!

So everything is illuminated.

—British poet Pope

Welcome to the fantasy world of quantum technology!

Quantum computing takes only 200 seconds to complete the computing power that today's most powerful supercomputer takes tens of thousands of years to complete; quantum encryption can instantly destroy the global encryption defense system, leaving hackers unemployed forever; no matter how far apart, quantum communication can allow satellite and probes landing on other planets to maintain zero-delay data transmission with the earth...

As the saying goes: if things go wrong, quantum mechanics ; cannot explain, travel through time and space.

So, what is quantum ? What are the magical characteristics of quantum mechanics and what are the subversive innovative applications? Next, " Future Semiconductor" will be revealed one by one for you.

· Solar range extender trailer with SpaceX Starlink Internet satellite system. solar cell converts light into current, a process called photovoltaic effect. This effect can only be explained when light appears in the form of light quantum - this is the cornerstone of quantum mechanics. Source: Tesla

· Using photon and electron spin qubits, the researchers demonstrated atom scale sensing for nuclear magnetic resonance, and by controlling the nuclear spin, they created nuclear qubits with longer coherence times than previously used electron spin qubits. Source: Purdue University

Quantum mechanics that violates the laws of classical mechanics

Physicists have told us through textbooks that the world composed of matter that follows the laws of classical motion (Newtonian mechanics, electromagnetic field theory ) is called the "classic world", and the world composed of matter that follows the laws of quantum mechanics is called the "quantum world". In the process of human exploration of the material world, the microscopic world of and the human world have a difference of more than 10^15 orders of magnitude in scale; such a huge difference is destined to be essentially different from the microscopic and macroscopic existence.

If we look at water, we can easily observe the spontaneous changing properties of the substance: at 100 degrees Celsius it evaporates into gas, and at 0 degrees Celsius it freezes into ice. In both cases, these new states of matter are the result of phase transitions in which water molecules rearrange themselves, thereby changing the properties of matter. Characteristics such as magnetic or superconductivity occur due to phase transitions of electrons in the crystal. For phase change at temperatures close to absolute zero at -273.15 degrees Celsius, quantum begins to cause entanglement and quantum mechanical effects begin to work.

Quantum (quantum) is the general term for discrete objects of light, matter and energy in the quantum world, which is the smallest and indivisible unit of energy. It can be microscopic particles such as photons, electrons, atoms, atomic nucleus, , elementary particles, or quantum systems at macroscopic scales such as BEC and superconductors.

Quantum technology is an emerging field of physics and engineering. Its principle is based on quantum mechanical properties such as quantum entanglement, quantum superposition and quantum tunneling and quantum tunneling . It is used in fields such as quantum computing, quantum measurement, quantum communication, quantum sensors, quantum cryptography, quantum simulation and quantum imaging.

Quantum mechanics is described by Einstein and Bol as "God plays dice with the universe", which brings many shocking conclusions: two particles thousands of miles apart can be instantly connected (quantum entanglement); the behavior of electrons has both the dual characteristics of waves and particles ( wave-particle duality ); uncertain photons can go in two directions at the same time (Heisenberg's principle of inaccurate measurement)... So much so that Einstein had to sigh: "The more successful quantum mechanics is, the more absurd it itself is."

· Double-slit experiment interferogram pattern appears in Source: sciencefocus

Quantum mechanics sounds unfathomable, but it is not a new field of disciplines that have emerged recently. In 1900, German physicist M. Planck proposed the concept of "quantum". It was perfected by a group of young genius physicists such as Einstein, Bohr, Schrödinger, and initially established a complete theory of quantum mechanics in the first half of the 20th century. Scientists have discovered that microscopic particles have completely different characteristics from the physical objects of the macroscopic world.

The physical objects of the macroscopic world are either particles or fluctuations. They follow the motion laws of classical physics, while all particles in the microscopic world have both particle nature and fluctuations. They obviously do not follow the motion laws of classical physics. However, in the past century, all quantum mechanics prophecies have been proven by experiments. It is generally recognized that quantum mechanics is the most successful theory in mankind to date.

Quantum mechanics is like Schrödinger's "dead and alive" cat, mysterious and fascinating.

Quantum entanglement

Quantum entanglement (Quantum entanglement), which constitutes the core principle of quantum encryption communication and quantum computing. Two entangled chestnuts, one is close to the eyes and the other is far away in the sky. When one of them is measured, the other will instantly sense and complete the corresponding state change, and the reaction speed is and .

For example, for example, genetic gene , any changes between relatives can be sensed; telepathic twins will have the same reaction, either crying or laughing. But it seems that this has nothing to do with distance. Some people can’t feel it no matter how close they are, but some people can feel it if they are thousands of miles away. The Book of Changes says "Silent and still, and then you can understand it." This is the truth. Therefore, as long as one of the states is measured, the other state will be determined accordingly.

· Take the metasurface of an ultra-thin glass sheet, covered with nanostructures made of semiconductor material gallium arsenide. When the laser passes through the metasurface, some photons coming out of the other side will appear in the form of entangled pairs. Source: Sandia National Laboratory and Max Planck Institute

964, physicist John Bell hypothesized that even if particles are far apart, this change can be induced and happen immediately. Bell's theorem is considered an important idea in modern physics, but it conflicts with other recognized principles of physics. For example, Albert Einstein proved several years before Bell proposed his theorem that the speed of information can not exceed the speed of light. The puzzled Einstein described this entanglement as "ghostly long-distance action." However, to the development of quantum mechanics to this day, generations of physicists and scientists have repeatedly confirmed that no matter how far apart, entangled particles do have an unbreakable correlation effect.

When researchers study entanglement, they often use a special crystal to generate two entangled particles from one crystal. The entangled particles are then sent to different locations. For this example, suppose the researchers want to measure the direction of the particle's rotation, which can be up or down along a given axle. Before measuring particles, each particle will be in the superposition state , or "rotate up" and "rotate down" at the same time.

If the researchers measure the direction of of a particle's spin and then repeat the measurements on its distant entanglement partner, the researchers will always find that this pair of particles is related: if one particle's spin is up, the other's spin will be down (the spin may inversely rise or both rise or fall, depending on how the experiment is designed, but there will always be correlation). In particular, assuming that the spins of two particles are measured in two different directions, the result will be found to violate the Bell inequality of ; in addition, there will be a paradoxical phenomenon: when one of the particles is measured, the other particle seems to know the occurrence and result of the measurement action. The beauty of this entanglement is that just knowing the state of a particle will automatically tell you some information about its companions, even if they are billions of light years apart.

The most widely used application of quantum entanglement is probably cryptography . The sender and the receiver establish a secure communication link, which includes a pair of entangled particles. Senders and receivers use entangled particles to generate private keys that only they know, which they can use to encode their messages. If someone intercepts the signal and tries to read the private key, the entanglement will be interrupted because measuring the entangled particles will change their state. This means that the sender and the receiver will know that their communication has been compromised. Another application of

entanglement is quantum computing, where a large number of particles are entangled together, allowing them to work together to solve some large and complex problems. For example, quantum computer with only 10 qubits can represent the same amount of memory as 2^10 traditional bits.

Quantum Tunneling

Quantum Tunneling (Quantum Tunneling), also known as tunneling effect and potential barrier penetration, is a characteristic of quantum, referring to the quantum behavior in which microscopic particles can pass through potential barriers greater than their own total energy. Similar to the phenomenon that can pass through "walls" that they would otherwise not pass through.

quantum tunneling effect cannot be explained by the viewpoint of classical mechanics. Under Newtonian mechanics system , because without external force, a small ball cannot pass through the wall, it will bounce back. However, under certain conditions, particles like atoms, electrons and other quantum scales can pass through insurmountable obstacles and pass through "walls" like ghosts.

· Source: byjus

Quantum tunneling is defined as a quantum mechanics process, where wave function can penetrate potential barriers. Transmission through barriers can be limited and depends exponentially on barrier width and barrier height. The wave function has the real probability of disappearing on one side and reappearing on the other side. The first derivative of the wave function is continuous. In the steady state case, the probability flux in the forward trajectory is spatially uniform. No waves or particles are eliminated. Tunneling occurs on barriers with a thickness of about 1-3 nm or less. It is predicted that quantum tunneling will physically limit the size of , the transistor used in microelectronics. This is because electrons can tunnel through transistors that are too small.

tunneling effect can be understood through the concept of Heisenberg's inaccuracy principle. In other words, the uncertainty of the precise position of electromagnetic particles allows these particles to break classical laws of physics and propagate in space without crossing potential energy boundaries. The tunneling principle and the uncertainty principle are compatible with each other because they treat quantum bodies as waves and particles at the same time.

· The electronic wave packet passes through an energy barrier. In classical mechanics, this energy barrier cannot be overcome, and the entire electron wave packet will be reflected back. In quantum mechanics, thanks to the existence of quantum tunnels, a small number of electron wave packets can pass through this energy barrier. Please note the faint light mass on the right. Source: Nature

barrier seems to be a shortcut to accelerate quantum tunneling.In 1962, a semiconductor engineer named Thomas Hartman from Texas Instruments (TI) wrote a paper defining a shocking phenomenon: when a particle passes through a tunnel, with a barrier thick enough, particles can pass from one side to the other faster than light passing through space at the same distance. That is, when there are particles quantum tunneling, it takes less time than when there are no obstacles.

Quantum tunneling seems to be faster than the speed of light, and the ability of particles to pass through obstacles has solved many mysteries for physicists. It explains the various chemical bonds and radioactive decays, and how the hydrogen nuclei in the sun overcome their repulsion and fuses, thereby producing enough light and heat to make life on Earth possible. It has contributed to the applications of quantum computing, tunneling diodes, scanning tunneling microscope , nuclear fusion , ultra-large scale integration (VLSI), and quantum biology.

Quantum superposition

Quantum superposition (Quantum superposition) means that a quantum exists in different places or in different states at the same time. It points out that, like waves in classical physics, any two (or more) quantum states can be stacked together, and the result will be another valid quantum state; instead, each quantum state can be represented as the sum of two or more other different states. Quantum computing is to cleverly manipulate quantum superposition states, using quantum mechanics principles as computational logic, which goes beyond the scope of Boolean algebra used in classical computing.

electrons have quantum features called spins, which is an inherent angular momentum. In the presence of a magnetic field, electrons may exist in two possible spin states, commonly referred to as spin up and spin down. Before being measured, each electron will have a limited chance of being in either state. It is only observed that it is in a specific spin state when measured.

· Parallel Universe Source: Pixabay

Another layer of meaning is that when we observe a quantum in a bunch of quantums, we often observe not a quantum state, but a superposition state of multiple quantums. Of course, this is another concept - the theory of parallel universes. The traditional view generally believes that the universe will not change and exists only. But quantum mechanics points out that there are more different possibilities for the universe.

Return to the Schrödinger cat experiment, according to classical physics, you must know whether the cat is dead or alive after the box is opened. In the quantum world, when the box is in a closed state and uncertain wave state, that is, the cat's life and death superposition. Multi-world interpretation believes that this state of coexistence has not been broken, but has created a parallel universe. In each universe, this quantum has a certain state, and humans are just observing this state of quantum in one of the specific universes. But Buddhism says "Three realms are only mind, ,000 Dharmas are only consciousness ", and our feelings seem to be the only thing that is certain.

Quantum mechanics is widely used in the scientific community, and the singular behavior of quantum systems has further stimulated people's guesses about how they play a role in brain work. To put it bluntly, our consciousness or "soul" is a system like quantum mechanics. They all have the attributes of "multi-line processing", "superposition", and "entanglement".

020 Nobel Prize winner in Physics Penrose proposed the "quantum soul theory". Penrose believes that the reason why humans even include other living organisms produces "consciousness activities" is because there is a "microtubules structure" similar to a "quantum computer" inside neuronal tissues. The generation of human consciousness (or soul) is essentially a "physical reaction of quantum mechanics." Through research on human brain neurons, Penrose believes that this "logical analysis" is based on the "quantum superposition state". At the same time, Penrose believes that consciousness itself will not "death", and after death, the soul leaves the body and transfers to another place in some form.

· Some scientists reveal life after death: the soul continues to exist at the quantum level. Source: Getty Images

The well-known American biologist Lankun proposed a systematic biology-centric theory, saying that life and organisms are the centers of the real world. When the heartbeat stops and the blood flow stops, that is, when the material elements are in a state of pause, the consciousness can still move. In addition to the physical activity, there are other traces of " quantum information " - the so-called "soul". Everything that happens now also happens in the parallel universe at the same time, that is, the equal consciousness on the other side will also be affected, that is, the so-called quantum entanglement or consciousness entanglement across the "world".

But now scientific research has not yet determined the relationship between quantum and soul and consciousness, but it cannot deny the existence of this relationship. Quantum mechanics itself is a "mysterious" science.

"I can tell you with certainty: no one really understands quantum mechanics." Dirac said.

Secondary quantum technology revolution started

quantum theory has been born over a hundred years ago, international academic circles have used a variety of experiments and mathematical methods to find that the wonderful characteristics of quantum exist objectively. The emergence of quantum theory triggered the first quantum revolution in the last century and gave birth to industrial applications including laser , transistor ( microchip ), laser diode and light emitting diode, electron microscope , magnetic resonance imaging (MRI), global positioning system (GPS) and computers.

"The war drum of the second quantum revolution has been ringing!" commented on the British magazine Nature. Entering the 21st century, new discoveries, new theories and new technologies of quantum emerge intensively, indicating that the second quantum revolution has entered a period of acceleration and starting.

"The first quantum revolution, people only asked what quantum theory could make us do, not why, it is passive observation and application." Academician of the Chinese Academy of Sciences and director of the Key Laboratory of Quantum Information of the Chinese Academy of Sciences Guo Guangcan said that the second quantum revolution was to actively utilize quantum characteristics to develop innovative applications such as quantum communication , quantum computing and quantum precision measurement.

For example, quantum communication is the only absolutely secure communication method that has been strictly proven mathematically. Since quantum has the characteristics of being non-redividable and non-replicable, once intercepted or interfered during transmission, the receiver can quickly discover it. In other words, quantum communication also has the function of "anti-eavesdropping". If someone eavesdrops, the information will be changed by eavesdropping, which can ensure that the content is top secret. The success of Chinese submarine experiments in quantum communications has verified that quantum can ensure airtightness in anti-eavesdropping work. Industry insiders predict that considering the long-term wide application in finance, defense, government and other fields, quantum needs to be used to make up for the shortcomings of China's advanced chips when promoting quantum communication forward.

A large number of scientific experiments have proved that quantum computing can make human computing power grow exponentially. For example, decomposing 300-bit and 5000-bit numbers, quantum algorithms will reduce the time required from 150,000 years to less than 1 second, from 5 billion years to 2 minutes! Traditional measurement technology can only detect the order of microns at the minimum, while quantum measurement can further be further refined to reach the order of atomic magnitude of thousands or tens of thousands of times. As a highly secure form of information transmission, quantum communication has been proven to be possible to transmit signals across galaxies or communicate with aliens.

Looking to the future, quantum computing is expected to provide new technical support for large-scale computing such as biomedicine, energy exploration, financial analysis, and weather forecasting; quantum measurements can leverage the advantages of precision and sensitivity, and will show their talents in scientific research, medical care, energy, disaster prevention and other fields; quantum communications combine quantum computing and encryption technology to form a high-speed and secure " quantum Internet ", which integrates technologies such as artificial intelligence, intelligent driving, military industry, and space exploration, which can add infinite possibilities to the future world.

Quantum technology will be the core of the next round of information technology, and the whistle has been blown before the competition of major powers! Regarding the major and cutting-edge applications of quantum technology, please pay attention to the next article:

" Quantum Technology | The most amazing illusion in history, bringing dreams into reality "