Expectation value in a linear superposition

In summary, the expectation value in a linear superposition is a way of calculating the average value of a physical quantity in a quantum system. It is calculated by multiplying each possible outcome by its corresponding probability and represents the most likely outcome for a physical quantity. When the system is measured, the expectation value may change depending on the outcome of the measurement. Its significance lies in its ability to make predictions and its fundamental role in quantum mechanics.
  • #1
solas99
69
1
In a linear superposition, what is the relationship between expectation value of, say, energy and the amplitude coefficients of the eigenfunctions?
 
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  • #2
That depends on what it is a superposition of. Normally, if you want to know the expectation value of some observable, you express the superposition in terms of "eigenfunctions" of that observable, meaning a superposition of states of a definite value for that observation. When you do that, the expectation value is a weighted average of those values, where the weights are the squared magnitude of the coefficients of the superposition.
 
  • #3
thank you :)
 

Related to Expectation value in a linear superposition

1. What is the expectation value in a linear superposition?

The expectation value in a linear superposition is a way of calculating the average value of a physical quantity in a quantum system. It takes into account the probabilities of different outcomes and uses them to determine the most likely value for the quantity.

2. How is the expectation value calculated in a linear superposition?

The expectation value is calculated by multiplying each possible outcome by its corresponding probability, and then summing all of these values together. Mathematically, it is represented as the inner product of the state vector and the operator representing the physical quantity.

3. What does the expectation value represent in a linear superposition?

The expectation value represents the most likely outcome for a physical quantity in a quantum system. It is not a guarantee of the actual measurement, but rather a prediction based on the probabilities of different outcomes.

4. How does the expectation value change in a linear superposition when the system is measured?

When the system is measured, the expectation value may change depending on the outcome of the measurement. If the measurement corresponds to one of the possible outcomes in the superposition, then the expectation value will be equal to that outcome. Otherwise, the expectation value will be equal to zero.

5. What is the significance of the expectation value in a linear superposition?

The expectation value is significant because it allows us to make predictions about the most likely outcome for a physical quantity in a quantum system. It is also a fundamental concept in quantum mechanics and is used in many calculations and experiments.

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