All Questions
Tagged with quantum-field-theory quantum-entanglement
73
questions
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Vacuum flucutuations = local entanglement between quantum fields?
I'm puzzled by this statement by Dieter Zeh: "Various types of quantum fluctuations (in particular vacuum fluctuations, often visualized in terms of 'virtual particles') are used to describe ...
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2
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58
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How can I construct a trivial product state in the continuum?
When working on the lattice it is easy to define a trivial product state. A state $|\psi\rangle$ is a trivial product state if it admits the following tensor decomposition,
\begin{equation}
|\psi\...
2
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63
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Operational meaning of mode dependence of mode-entanglement
In this paper, Vedral shows that the entanglement in second quantized states can depend on the choice of modes. As a simple example, he points out that the ground state of two non-interacting harmonic ...
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128
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Does the no signalling theorem in quantum mechanics beg the question?
I had always thought similarly and then came across a paper here that argues this.
The abstract is as follows:
Many authors state that quantum nonlocality could not involve any controllable ...
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103
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Decoherence time of quarks
I have been reading papers on using top quark's use as a probe for new physics using quantum information theoretic observables such as concurrence. One of the reasons they provide for using a top ...
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Entanglement entropy in states with particle content
I am studying entanglement and its measurements in the context of a lattice model of the Dirac theory. The idea is that one has two bands, symmetric with respect to $E=0$, and the groundstate is ...
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Is Von Neumann entropy in QFT related to the two-point function?
Suppose I have a scalar QFT. Is the Von Neumann entropy related to the two point function? More generally, given the two point function and an entangling surface, can we calculate the Von Neumann ...
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Resource Recommendation for Quantum Information Theory especially entanglement in quantum field theory
I am trying to start learning quantum information from a theoretical point of view not involving aspects of quantum computing. The main thing that I want to understand is entanglement from both a ...
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How is entanglement of non-spin variables incompatible with local realism?
It seems to me that spin/polarization entanglement is the only spooky one. That's because the entanglement of other observables would happen even in regular classical physics if we made a "...
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What's wrong with my argument about entanglement entropy in QFT being time-independent?
Let's say we need to compute the entanglement entropy (EE) of a subsystem $A$ ($A=[0,L]$, $L>0$) in a 2D CFT.
The density matrix of the total system (i.e., the real axis) is given by
$$
\rho(t)=\...
- 21
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Proof of the expression for entanglement entropy from correlation matrix
Let a quantum system be described by a correlation matrix
$$
C_{ij} = \langle c_i^\dagger c_j \rangle\ ,
$$
which we can split in components $A$ and $\bar{A}$. I have read that we can calculate the ...
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Is the circuit unitary in Nielsen's method for calculating complexity?
I was trying to learn how to calculate circuit complexity (1707.08570) when I chanced upon a seemingly confusing concept. The "Nielsen method" involves looking at a unitary transformation $U$...
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How to describe the entanglement in the jets?
Consider a pair of quark and anti quark flew away and generate the "jets"(whatever that meant).
But from the color conservation, it was assured that the seemly isolated jets that was ...
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Can we determine when the lowest-energy state cannot be annihilated by any local operator, just by inspection of the Hamiltonian?
Relativistic quantum field theory (QFT) has the property that the lowest-energy state cannot be annihilated by any operator that is localized in a finite region of space (references 1,2,3). In other ...
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Hamiltonian basis in multiple particle systems
I have a question about the choosing of basis that compose the Hamiltonian of multiple systems. For example if we have a system of N particles, that depend in our case of Pauli matrixes i will give ...
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