How Do You Compute the Adjoint of a Quantum State in Dirac Notation?

In summary, to express <ψ| as a linear combination of <a| and <b|, we use the given equation <ψ| = e-iπ/5<a| + e-iπ/4<b|. The properties characterizing the bra <a| associated with the ket |a> include that it will give 1 when applied on |a> (assuming normalisation), and it is a linear function that yields a complex scalar when applied on other elements in the vector space of |a>.
  • #1
spaghetti3451
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Homework Statement



1. Given that |ψ> = eiπ/5|a> + eiπ/4|b>, express <ψ| as a linear combination of <a| and <b|.

2. What properties characterise the bra <a| that is associated with the ket |a>?

Homework Equations



The Attempt at a Solution



1. <ψ| = e-iπ/5<a| + e-iπ/4<b|

2. a. The bra <a| when applied on the ket |a> will give 1.
b. The bra <a| is a linear function, which applied on the other elements of the vector space of |a> will give a complex scalar.

Comments are welcome.
 
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  • #2
looks good to me. although 2)a) is only true when |a> is a normalised state vector. If you can assume that it is normalised, then its fine.
 

Related to How Do You Compute the Adjoint of a Quantum State in Dirac Notation?

1. What is Dirac Notation?

Dirac Notation, also known as bra-ket notation, is a mathematical notation used in quantum mechanics to represent vectors and operators. It was introduced by physicist Paul Dirac in the 1930s.

2. How is Dirac Notation used in quantum mechanics?

Dirac Notation is used to represent quantum states, observables, and measurements in quantum mechanics. It is a concise and powerful notation that simplifies complex calculations and allows for a more intuitive understanding of quantum phenomena.

3. What do the symbols in Dirac Notation mean?

The bra-ket notation uses the symbols ⟨ and ⟩ to represent the "bra" and "ket" vectors, respectively. The "bra" vector ⟨a⟩ represents the complex conjugate transpose of the "ket" vector |a⟩. The inner product of two vectors ⟨a|b⟩ represents the probability amplitude of measuring |a⟩ given the initial state |b⟩.

4. How does Dirac Notation handle vector operations?

In Dirac Notation, vector operations such as addition, scalar multiplication, and inner product can be represented using the corresponding symbols +, *, and ⟨|⟩. The notation also allows for the representation of linear operators as matrices, making it easier to perform calculations.

5. Are there any limitations to using Dirac Notation?

While Dirac Notation is widely used in quantum mechanics, it is not a complete mathematical system. It does not provide a rigorous definition of vectors and operators, and it cannot handle infinite-dimensional vector spaces. Therefore, it is often used in conjunction with other mathematical notations to fully describe quantum systems.

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