Questions tagged [angular-momentum]
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Why does Sakurai's book use the gyromagnetic ratio of the electron as $\frac{e}{m_e c}$ instead of $\frac{e}{m_e}$?
I'm studying quantum computing, but I had to review some concepts in supplementary readings, where I came across the following question about a simple detail: Why does Sakurai's book (near Eq. 1.1) ...
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$S^2$ expectation value of a circuit seems wrong
I need to rewrite a following circuit from Cirq to Qiskit with $2\varphi = \pi$.
It's a circuit representing an initial state for VQE calculation. Considering, that ...
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Qiskit: evaluating expectation value of S^2 operator
I am trying to obtain the expectation value of the S^2 operator with respect to VQE wave function in an older version of qiskit (0.26). To that end, I tried:
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What is the physical significance of the general rotation operator $R(\hat n,d\theta)=I-id\theta (\hat n\cdot\vec J)$?
John Preskills lecture notes (here) contain an equation for a general rotation operator (eqn 2.25, page 11):
$$R(\hat{n},d\theta)=I-id\theta \hat{n}\cdot \vec{J},$$
where $\vec{J}$ is angular momentum,...
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What are spin-coherent states?
Trying to understand the paper; https://arxiv.org/pdf/1702.02577.pdf and ran into "spin-coherent" states.
I wonder those are.
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How to prove the fundamental equation in the theory of angular momentum $\sum_{l=x,y,z}\langle J_l^2\rangle\le\frac{N(N+2)}{4}$?
How to prove the inequality$$\sum_{l=x,y,z}\langle J_l^2\rangle\le\frac{N(N+2)}{4}$$
where $J_l = \mathop{\Sigma}_{i=1}^N \frac{1}{2}\sigma_l^{i}$, and $\sigma_l^i$ is pauli matrix acting on the $i$th ...
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