All Questions
Tagged with coherent-states many-body
12
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76
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Majorana Boson Coherent States
Consider $a$ be a bosonic operator, and we define $\Phi = a+a^{\dagger}$ and it is clear that $\Phi^{\dagger}=\Phi$ that implies "Majorana Boson". Now, i want to find the coherent states for ...
- 177
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Identity of bosonic coherent states
I have a short question about the meaning of the identity of the bosonic coherent states.
Before I ask the question I will explain some background.
The eigenstate of the bosonic annihilation operator $...
- 237
3
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222
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Advantage of coherent path integral
I think(?) I am quite familiar with path integral over phase space, but not familiar with the coherent state path integral. What is the advantage of this coherent path integral besides the usual path ...
- 3,622
9
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Calculating free energy from coherent state path integral
Edit: It turns out that problem encountered in this question is not limited to BdG Hamiltonians.
I am having trouble in using the coherent state path integral approach to calculate the free energy. ...
- 660
2
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Fock Space and Coherent state
Can a coherent photon state also belong to the Fock space? If yes, under what conditions? For example I read that
$$\exp\bigg\{-\frac{1}{2}\sum_i|\alpha_i|^2\bigg\}\exp\bigg\{-\sum_i\alpha_ia_i^{\...
- 3,992
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BCS groundstate as eigenstate of the Cooper pair annihilation operator
In section 3.7 of his book Introduction to Superconductivity (2nd Ed.), Tinkham states that
[...] we note that S has the eigenvalue $e^{i\varphi}$ in a BCS state in which the the phase of $\Delta$ [.....
- 1,540
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How is the BCS ground state a coherent state?
A coherent state is defined as the eigenstate of the annihilation operator $\hat{a}$. It can be obtained from the vacuum of the number operator by acting with displacement operator: $$|z\rangle=\hat{D}...
- 11.8k
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Harmonic oscillator in QFT
Given a single bosonic mode with frequency $\omega_0$, such that $\hat{H}=\hbar\omega_0(\frac{1}{2}+\hat{a}^{\dagger}\hat{a})$ how should one show the equivalence between the coherent state path ...
- 892
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Coherent state of "generalized" annihilation operator
We all know that the coherent state $|\alpha \rangle=\sum_n \, \frac{\alpha^n}{n!}\,(a^{\dagger})^n \, |0\rangle $ is an eigenstate of the annihilation operator: $a |\alpha\rangle = \alpha |\alpha \...
- 1,037
2
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Coherent states and classical limit
Consider the coherent state
$$ |\phi \rangle = \exp \left( \zeta \cdot \sum_\alpha \phi_{\alpha} a_{\alpha}^\dagger \right) | 0 \rangle.$$
For the case of bosons ($\zeta = +1$), the $\phi_\alpha$'s ...
- 1,154
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Majorana Fermion Coherent States
I was wondering if there are coherent states for Majorana operators, so, states that fulfill the relation
\begin{align}
\hat{\gamma}_A |a,b\rangle &= a |a,b\rangle \\
\hat{\gamma}_B |a,b\...
- 31
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Connection between Hubbard-Stratonovich and (generalized) coherent states
A simple-minded mean-field approximation for the Bose-Hubbard model consists in writing operators as $\hat{a}_i = \alpha_i + \hat{\delta \alpha}_i, \alpha_i \in \mathbb{C}$ and only include terms up ...
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