Can Quantum Mechanics Have 'Elegant' Trajectories in Hilbert Space?

Logic Cloud
Messages
21
Reaction score
0
State-space trajectories in classical mechanics can be used to nicely represent the time evolution of a given system. In the case of the harmonic oscillator, for instance, we get ellipses. How does this situation carry over to quantum mechanics? Can the time evolution of, say, the quantum harmonic oscillator be represented by some 'trajectory' in Hilbert space? The obtained wave functions do not seem to lend themselves for such 'elegant' representations.
 
Physics news on Phys.org
If you choose a unit vector, say for spin 1/2, the trajectory in Hilbert space is just rotation of a unit vector. It's very elegant.
 
There is also the trajectories in the projective hilbert space and their hamiltonian dynamics and poisson brackets.
 
Logic Cloud said:
State-space trajectories in classical mechanics can be used to nicely represent the time evolution of a given system. In the case of the harmonic oscillator, for instance, we get ellipses. How does this situation carry over to quantum mechanics? Can the time evolution of, say, the quantum harmonic oscillator be represented by some 'trajectory' in Hilbert space? The obtained wave functions do not seem to lend themselves for such 'elegant' representations.

If that sort of thing interests you here is the book to get:
https://www.amazon.com/dp/0387493859/?tag=pfamazon01-20

Be warned - its what mathematicians call decidedly non-trivial - meaning it's hard.

Said with a German accent - We have ways and means of stopping you asking certain questions :-p:-p:-p:-p:-p:-p:-p:-p:-p

Thanks
Bill
 
Last edited by a moderator:
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!
According to recent podcast between Jacob Barandes and Sean Carroll, Barandes claims that putting a sensitive qubit near one of the slits of a double slit interference experiment is sufficient to break the interference pattern. Here are his words from the official transcript: Is that true? Caveats I see: The qubit is a quantum object, so if the particle was in a superposition of up and down, the qubit can be in a superposition too. Measuring the qubit in an orthogonal direction might...
Back
Top