Why is a time-dependent Hamiltonian different in quantum mechanics?

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In summary, in classical mechanics, the Hamiltonian of a system with explicit time dependence will not be equal to the system's total energy. However, this is not necessarily true in quantum mechanics since the particles and fundamental interactions remain the same. There is no clear example of this difference at the moment.
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dEdt
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In classical mechanics, if there's an explicit time dependence in the Hamiltonian of a system, then it won't be equal to the system's total energy. Why isn't this true in quantum mechanics?
 
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In classical mechanics, if there's an explicit time dependence in the Hamiltonian of a system, then it won't be equal to the system's total energy.
Can you show an example of this?

If the time-dependence in the Hamiltonian is just some external potential, it should be fine. And I do not see how you get different time-dependent expressions in quantum mechanics - the particles and fundamental interactions have to stay the same.
 
  • #3
mfb said:
Can you show an example of this?

No, I can't. I just confused myself. Thanks.
 

FAQ: Why is a time-dependent Hamiltonian different in quantum mechanics?

What is a time-dependent Hamiltonian?

A time-dependent Hamiltonian is a mathematical function that describes the dynamics of a system over time. It is used in quantum mechanics to calculate the evolution of a quantum system over time.

2. How is a time-dependent Hamiltonian different from a time-independent Hamiltonian?

A time-independent Hamiltonian is a function that does not change with time, while a time-dependent Hamiltonian changes with time. Time-dependent Hamiltonians are often used to describe systems that are subject to external forces or are evolving over time.

3. What is the role of the time-dependent Hamiltonian in quantum mechanics?

The time-dependent Hamiltonian is a fundamental concept in quantum mechanics. It is used to calculate the time evolution of a quantum system and to predict the probabilities of different outcomes of observations or measurements.

4. How is the time-dependent Hamiltonian related to the Schrödinger equation?

The Schrödinger equation is a mathematical equation that describes the time evolution of a quantum system. The time-dependent Hamiltonian is a key component of the Schrödinger equation, as it determines the energy of the system and how it changes over time.

5. Can time-dependent Hamiltonians be solved analytically?

In most cases, time-dependent Hamiltonians cannot be solved analytically. However, there are some special cases where analytical solutions are possible, such as in simple harmonic oscillators or in certain time-dependent perturbation problems. In general, numerical methods are used to solve time-dependent Hamiltonians.

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