Are energy bands in solid state timeless?

[jake jot]

The wave function or Schroedinger equation is timeless, correct? You can reverse the equations and forward it.

Our arrow of time comes due to decoherence in macroscopic object.

How about energy bands in solid state. Do you consider it as timeless wave function, or is it decohered?

 

[mfb]

The Schroedinger equation tells you how the wave function changes with time. I'm not sure what you mean by "timeless". It's time symmetric (in nonrelativistic quantum mechanics). It doesn't matter if you consider a particle in a box, or 10²⁷ particles, or the band structure in a solid.

 

[jake jot]

The Schroedinger equation tells you how the wave function changes with time. I'm not sure what you mean by "timeless". It's time symmetric (in nonrelativistic quantum mechanics). It doesn't matter if you consider a particle in a box, or 10²⁷ particles, or the band structure in a solid.

Time symmetric is not the same as our macroscopic time. So an electron wave function in a solid treads upon the imaginary as well as future and past domains, linking and coupling all these regions with one another. Information can pass from one of these domains into the other. Is this correct? Something we can't do with our unsymmetric time (due to arrow of time introduced by decoherence).

 

[Drakkith]

Time symmetric is not the same as our macroscopic time. So an electron wave function in a solid treads upon the imaginary as well as future and past domains, linking and coupling all these regions with one another. Information can pass from one of these domains into the other. Is this correct?

That doesn't sound correct at all.

 

[mfb]

Time symmetric is not the same as our macroscopic time. So an electron wave function in a solid treads upon the imaginary as well as future and past domains, linking and coupling all these regions with one another. Information can pass from one of these domains into the other. Is this correct? Something we can't do with our unsymmetric time (due to arrow of time introduced by decoherence).

I have no idea what you are trying to say here, and I agree with Drakkith.

 

[jake jot]

I have no idea what you are trying to say here, and I agree with Drakkith.

Why is it wrong? There are many quantum interpretations. Let's use one where it has ontological aspect, and where the electron wave function can tread into other aspect of existence. Therefore, in solid crystal lattice, an electron wave function become severely smeared and spread out.
But the smearing is not only through space. It's also through the [higher dimensions]. In other words, an electron wave function in a crystal treads upon the imaginary as well as future and past domains, linking and coupling all these regions with one another. Information can pass from one of these domains into the other.

What part of the above is wrong (any or all). Kindly correct which part is
wrong and why. So if it is wrong. Then can find other more exotic processes that can explain reality better.

 

[Drakkith]

What part of the above is wrong (any or all). Kindly correct which part is
wrong and why. So if it is wrong. Then can find other more exotic processes that can explain reality better.

No. We don't do that here. We teach actual science, we don't discuss people's personal interpretations or theories.

 

[mfb]

Why is it wrong?

To answer that question you would first have to phrase it more clearly so others can understand what you mean.

 

[jake jot]

To answer that question you would first have to phrase it more clearly so others can understand what you mean.

Let's discuss actual physics.
When we make measurement, we don't really have access to the whole wave function but only the collapsed part, and randomly. So from the point of view of particle physicists, only a tiny information is acquired.

I'd like to understand from the point of view of the electron. Since it is smeared in the solid. And solid is time symmetric. Then it can theoreticaly access the past and future, right?

If wrong, why can't it when electron is smeared wave function and it is time symmetric.

Reference:

https://phys.org/news/2015-07-time-symmetric-quantum-theory-causality-free.html

"The laws of classical mechanics are independent of the direction of time, but whether the same is true in quantum mechanics has been a subject of debate. While it is agreed that the laws that govern isolated quantum systems are time-symmetric, measurement changes the state of a system according to rules that only appear to hold forward in time, and there is difference in opinion about the interpretation of this effect."

 

[DrClaude]

Thread locked pending moderation.

 

[berkeman]

After a Mentor discussion, this thread will remain closed. Thanks everybody who tried to help the OP.