Good morning.
I want to tell you more easily and fun, but because of lack of my writing skill, it seems that it is somewhat difficult to accept when I touch contents. It's a difficult topic, but I will do my best to make it more interesting to read.
In the last hour, I had time to learn about the basic principles of quantum computers compared to ordinary computers.
Simple review
The quantum computer uses a state in which all possible states are superimposed and entangled.
- Natural phenomena are subject to probability.
- Measurement or perturbation behavior itself affects the state.
Term Definition
- Quantum superposition: A quantum mechanical property that exists at the same time as all possible states that a particle can have in relation to energy or position.
- Quantum entanglement: A state in which two or more quantum states are closely linked to one another. In the entangled state, both states are inevitably determined depending on the result even if one state is determined in the separated physical system.
As a result of the measurement, the initial quantum state can not be known!
When two or more particles are closely related to one another, they cause entanglement by overlapping states. The individual states of the two particles entangled in a quantum entanglement are never known until they are measured. This is because it affects the instantaneous state of the measurement and confirms it as one of the specific inherent states allowed. Acquiring information about a system through measurement inevitably disturbs the state of the system.
To help you understand, let's compare this to a situation in reality.
Measurement in the classic state
A measures 1kg of mass and 1cm of square steel plate.
Repetition of several runs will not change the mass and length of the steel plate under the same physical conditions (isothermal, equilibrium). Measuring the mass does not change the length, and measuring the length will not change the mass. The measurement in the classical state can not be said that the measurement action affects the state and the initial state can be fully estimated by the measurement result.
Measurement of Quantum State
A and B are loving lovers.
Situation (1)
A: B, I love you.
B: I love you too.
→ B feels a greater love for A who expresses love.
Situation (2)
A: B, I love you.
B: Yes. Thank you ~
→ B did not express my feelings, but I feel burdened inside, and I wonder if I really love A.
In case (1), A and B will love more. But in the case of situation (2), A may express the love in a bad way, and it may be that B has exacerbated the relationship between the two. When I express my love through the relationship between A and B, I can guess B's answer and reaction, but no one knows what kind of result. Likewise, measurement of the quantum state affects the state of the measurement action, and the initial state can not be fully estimated as a result of the measurement.
It may be a rather pitiful analogy, but did you get a little more understanding?
Quantum entanglement transcends the principle of locality!
If you determine the state of one of the two quantum entangled quantities through the measurement, you can immediately determine the state of the other. It is as if the information is moving instantaneously from one system to another system in an instant. This phenomenon is called quantum teleportation. There is a point to go into before you go deeper.
The principle of physics, called the locality, is that two objects that are spaced far apart can never directly affect each other. In order to influence each other, it is necessary to exchange information in some form and information about the state of the system in the transmission of information can be always mediated only through the system.
Let's think of the earth revolving around the sun. The sun and the Earth are all-or-nothing. If the sun suddenly pops from space at any moment! What would be the movement of the earth if it disappeared? Classically, as soon as the sun disappears, the earth can be thought of as moving straight out of its orbit. However, considering the theory of relativity, applying the principle of locality, the effect of the sun immediately after the disappearance of the propagation of light at the speed of reaching the earth is the beginning of the linear motion of the earth.
Physicists such as Albert Einstein (E), Boris Podolski (P), and Nathan Rosen (R) deny the quantum mechanical entanglement by using the EPR theory that physics must have such a locality. If one of the two entangled states is determined, it does not affect the periphery of the system and immediately affects the other state, which itself violates the principle of locality.
But John Stuart Bell's experiments show that quantum entanglement can be mediated without the principle of locality being applied and without the information going around the system. EPR theory was not a truth that could be applied to all physics, and it is not explained in the state of quantum entanglement. Because of this, it remains in the name of EPR paradox and is often mentioned in connection with the reversal of causality and the destruction of synchronicity.
Einstein said God did not play backgammon. Although I published the theory of relativity, which can be called the beginning of quantum mechanics, I have shown the most negative attitude to the quantum mechanics that axioms that natural phenomena are subject to probability. Is not it surprising that Einstein once said something wrong?
The quantum entanglement state free from the principle of localization shows that determining the state of one particle can instantly determine the state of another particle without mediating the system. Currently, technically successful transmission of quantum information between two entangled atoms has not yet been achieved beyond the molecular level. However, this does not mean that information is transmitted faster than light, contrary to the axiom of relativity. Quantum transitions also transfer information from one location to another without having to move the physical particles. Therefore, it should not be overlooked that it is a means of communication other than transportation, which is related only to the transmission of information. Some people think of quantum transit as a kind of cut-and-paste courier concept in which the object is resolved into particles by moving the object to another place and reassembling it, reminiscent of the scene on the movie star track. Please correct misunderstandings through.
As I wrote it, the contents became longer, so I could not tell you about quantum superposition and quantum entanglement at first. Today we have dealt with the magical phenomena of nature caused by quantum superposition and quantum entanglement, especially the quantum state measurement and quantum instantaneous transfer. Next time, let's look at quantum communication security and quantum parallelism related to quantum superposition and quantum entanglement.
I want to communicate easily and funly, but when I deal with difficult subjects, I am afraid that I may be feeling the contents too much. If you can post your question in a comment, I will reply as easily and concisely as possible within the range that I can explain.
