Non-adjoint Conjugate of Pure State Vector

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In summary, the conversation discusses a system with pure state vectors A and B, where B is an anti-parallel vector to A. This relationship is not just a simple conjugate, as the inner product between B and A is not equal to 1. This concept is similar to harmonics and can be seen as a distortion in the complex plane. The conversation ends with a question about better understanding this relationship and its connection to solving quadratic equations.
  • #1
Pythagorean
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If I have a pure state vector of a system (let's call it A):

-0.4431 + 0.2317i
-0.4431 + 0.2317i
0.5000
0.5000

A particularly interesting symmetry in the system allows a similar pure state (B):

-0.4431 - 0.2317i
-0.4431 - 0.2317i
0.5000
0.5000

the absolute value of the inner product is
|B'*A| = .8861
(as opposed to 1, since these are only conjugates of each other and not adjoints, or
hermitian conjugates. For instance, A'*A = 1 where A' is the adjoint of A).

question:
is there a specific name for the relationship between A and B besides just conjugate? In the literature, and especially with state vecto.rs, conjugate and adjoint are used interchangeably.

This is a classical case of misleading intuition with the complex space. I imagined that as you rotated the vector around, there would be a second position (B) that would return 1 if you took the inner product of it with A, by symmetry. I didn't suspect that the inner product could detect an "anti-parallel" vector.

Of course, note that as you rotate the vector B around, it has two clear maximum peaks. The largest peak is when B = A so your inner product is A'*A = 1 exactly, but the second largest peak occurs when B is "anti-parallel" (the conjugate non-adjoint) at the .8861 value mentioned.

In this respect, it reminds me of harmonics. I expected the two peaks opposite each other to both go to 1, but they did not and now I want to better understand what exactly I'm doing. It looks like maybe I'm only rotating it around the imaginary plane, not the whole complex plane, and the projection in the complex plane gets distorted (shortened) somehow.
 
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  • #2
When solving quadratic equations one usually gets conjugates as zeroes. E.g. the formula for ##x^2+px+q=0# is solved by conjugates. This is also true for higher degrees, just that the automorphisms are not of order 2 then. So it is very likely that your observation is due to the specific underlying equations.
 

FAQ: Non-adjoint Conjugate of Pure State Vector

What is a "Non-adjoint Conjugate" of a Pure State Vector?

The non-adjoint conjugate of a pure state vector is a mathematical concept used in quantum mechanics. It refers to the complex conjugate of a pure state vector, where the imaginary part is multiplied by -1. This helps to simplify calculations and equations in quantum mechanics.

How is the Non-adjoint Conjugate of a Pure State Vector represented?

The non-adjoint conjugate of a pure state vector is typically represented by adding a dagger symbol (†) to the state vector. For example, if the pure state vector is represented as |ψ⟩, then the non-adjoint conjugate would be written as ⟨ψ†|.

What is the difference between the Non-adjoint Conjugate and the Adjoint of a Pure State Vector?

The non-adjoint conjugate and the adjoint of a pure state vector are related, but they are not the same. The adjoint of a pure state vector is the Hermitian conjugate, which is the complex conjugate of the vector transposed. The adjoint is used to calculate inner products, while the non-adjoint conjugate is used to simplify equations.

How is the Non-adjoint Conjugate of a Pure State Vector used in Quantum Mechanics?

The non-adjoint conjugate of a pure state vector is used in quantum mechanics to simplify equations and calculations. It is an important concept in quantum mechanics as it is used to calculate probabilities and other properties of quantum systems.

Can a Non-adjoint Conjugate of a Pure State Vector be a Pure State Vector itself?

No, the non-adjoint conjugate of a pure state vector is not a pure state vector itself. It is a mathematical operation on the pure state vector and does not represent a physical state in quantum mechanics.

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