What does |0> mean? ie what does the | > mean/do?

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Discussion Overview

The discussion centers around the notation |0> and its significance in quantum mechanics, particularly in relation to the concept of "ket" vectors and their implications for representing states in a quantum system. Participants explore the meaning and purpose of the notation, as well as its connections to other mathematical symbols used in the field.

Discussion Character

  • Conceptual clarification, Technical explanation, Debate/contested

Main Points Raised

  • Some participants suggest that | > serves primarily as a decorative notation, similar to the use of arrows or hats in vector notation.
  • Others propose that the notation is not arbitrary, as it relates to the inner product and expectation values in quantum mechanics, particularly when considering leading to .
  • One participant identifies |0> specifically as representing the ground state of a quantum system, indicating that the notation denotes a "ket" vector with a specific meaning in the context of energy states.

Areas of Agreement / Disagreement

Participants express differing views on the significance of the notation | >, with some seeing it as merely decorative while others argue it has deeper mathematical implications. The discussion remains unresolved regarding the full extent of its meaning and usage.

Contextual Notes

Some assumptions about the familiarity with quantum mechanics and the mathematical framework may be implicit in the discussion. The relationship between the notation and its application in quantum states is not fully explored, leaving some aspects open to interpretation.

Lee
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What does |0> mean? ie what does the | > mean/do?
 
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| > is just a decoration; it makes something look different. It's no different than when you put a little arrow over your vectors, or little hats over your unit vectors.
 
Ah, right. I thought it was maybe linked to < > meaning expectation value.
 
Lee said:
Ah, right. I thought it was maybe linked to < > meaning expectation value.

Well when you take the inner product of <x| with |x> you get <x|x>, which is a number and can be thought of as an expecttion. So the notation ("Bra and ket") isn't entirely arbitrary.
 
Lee said:
What does |0> mean? ie what does the | > mean/do?

[itex]|0\rangle[/itex] stands for the ground state for a quantum system (the state with the minimum possible energy). The [itex]|\rangle[/itex] with "something" in between the vertical line and the angle means that the "something" is a "ket" vector.

Daniel.
 

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