Heisenberg vs schrodinger picture

RedX
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How does one work in the Heisenberg picture? Can you dequantize and solve the classical Hamilton's equations and somehow requantize this classical solution for the time evolution of the position and momentum operators (and more importantly the eigenvectors)? How would one go about doing that, and which is more useful, the Schrodinger picture or the Heisenberg picture or the Dirac/interaction/intermediate picture (the latter is where your frame rotates at the rate of the time-independent part of the Hamiltonian)?
 
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RedX said:
How does one work in the Heisenberg picture? Can you dequantize


What do you mean by "dequantize"??The quantization postulate goes one way only.
Are u referring to Heisenberg & Schroedinger pictures in classical dynamics...??U needn't QM to do that...

RedX said:
and solve the classical Hamilton's equations

No,u do not solve the classical Hamiltonian equations for purpose involving the word "quantum"...

RedX said:
and which is more useful, the Schrodinger picture or the Heisenberg picture or the Dirac/interaction/intermediate picture (the latter is where your frame rotates at the rate of the time-independent part of the Hamiltonian)?

Depends on the situation.They're all EQUIVALENT and useful in the same proportion...

Daniel.
 
It's just that my textbook makes a big fuss about the similarity of Heisenberg's picture to the classical Hamilton's equations, showing that the quantum operators obey the same differential equations as the variables in the classical picture. I was just thinking that you could replace the quantum Hamiltonian with the corresponding classical Hamiltonian (dequantize - I guess I'm inventing words), solve the classical equations for momentum and position variables, and somehow requantize these variablesto get the position and momentum operator as a function of time (hence almost all other variables). Guess I was hopeful that quantum mechanics would be easy . One wonders why the author even bothers pointing out the similarity between classical Hamilton's equations and Heisenberg's picture when you can't use that similarity to your advantage.
 
RedX said:
It's just that my textbook makes a big fuss about the similarity of Heisenberg's picture to the classical Hamilton's equations, showing that the quantum operators obey the same differential equations as the variables in the classical picture.


That's true.

RedX said:
I was just thinking that you could replace the quantum Hamiltonian with the corresponding classical Hamiltonian (dequantize - I guess I'm inventing words), solve the classical equations for momentum and position variables, and somehow requantize these variablesto get the position and momentum operator as a function of time (hence almost all other variables). Guess I was hopeful that quantum mechanics would be easy .

Nope,it doesn't work that way.It never will.

RedX said:
One wonders why the author even bothers pointing out the similarity between classical Hamilton's equations and Heisenberg's picture when you can't use that similarity to your advantage.

U can,just as long as u decide to do everything in the Heisenberg picture.Why would you need analogies?

Daniel.
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
If we release an electron around a positively charged sphere, the initial state of electron is a linear combination of Hydrogen-like states. According to quantum mechanics, evolution of time would not change this initial state because the potential is time independent. However, classically we expect the electron to collide with the sphere. So, it seems that the quantum and classics predict different behaviours!
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