How to Determine the Hamiltonian for a Two-Level System with Tunneling?

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SUMMARY

The discussion focuses on determining the Hamiltonian for a two-level quantum system with tunneling effects. The user presents a scenario involving a particle in a box divided by a thin membrane, where the wave functions Ψ1 and Ψ2 represent the probability amplitudes of the particle being on either side. The condition ihΨ2 = K*Ψ1 is established, leading to the need for a 2x2 Hamiltonian matrix. The user seeks guidance on deriving the matrix elements using Schrödinger's equation and the linearity principle.

PREREQUISITES
  • Understanding of quantum mechanics principles, particularly two-level systems.
  • Familiarity with Schrödinger's equation and its applications.
  • Knowledge of wave functions and probability amplitudes in quantum systems.
  • Basic understanding of Hamiltonian operators and matrix representations.
NEXT STEPS
  • Study the derivation of Hamiltonians for two-level systems in quantum mechanics.
  • Learn about tunneling phenomena and its mathematical representation in quantum mechanics.
  • Explore the use of matrix mechanics in quantum systems, focusing on 2x2 matrices.
  • Investigate the implications of linearity in quantum mechanics and its effect on wave functions.
USEFUL FOR

Quantum physicists, students studying quantum mechanics, and researchers interested in tunneling effects in two-level systems will benefit from this discussion.

Juan Carlos
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Hi!
I'm having problems with this simple problem:

Consider two level system: a box divided by a thin membrane. Let
 
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Hi!
I'm having problems with this simple problem:

Consider two level system: a box containing one particle, the box is divided by a thin membrane. Let Ψ1 and Ψ2 the probability amplitude (time-dependent only) of being on the left and right side. The particle can tunnel through the partition: so the next condition holds:

ihΨ2=K*Ψ1 where =Temporal partial derivate
K=constant

Using this condition I have to write the most general hamiltonian of the system.

Of course the wave function is:
Ψ(t)=Ψ1⎪L〉+ Ψ1⎪R〉

And the hamiltonian should be a 2x2 matrix. So I think that the actual problem is determine the matrix elements.

I've tried to use the Schordinger's equation directly:

ih Ψ(t) = ih Ψ1⎪L〉+ ih Ψ1⎪R〉= H Ψ1⎪L〉+H Ψ1⎪R〉 (Using linearity)
And using the condition:

ih Ψ1⎪L〉+ K*Ψ1⎪R〉= H Ψ1⎪L〉+H Ψ1⎪R〉

And then?

Help Please!

Note: I know the general matrix form for the Hamiltonian, but… that is what I'm trying to look for…
 

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