All Questions
24
questions
2
votes
1
answer
67
views
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 ...
3
votes
0
answers
103
views
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 ...
- 309
1
vote
0
answers
45
views
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 ...
2
votes
2
answers
773
views
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 ...
- 601
2
votes
1
answer
108
views
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 $U$...
0
votes
0
answers
295
views
Good book to study entanglement in detail
Can anybody suggest a good book to know about quantum entanglement? I am a master's student and I have good knowledge of quantum mechanics. I want to know more on this subject. It would also be useful ...
2
votes
0
answers
126
views
Why does the no-cloning theorem imply the monogamy of entanglement?
I have seen papers where they mentioned that the monogamy of entanglement can be seen as a consequence of the no-cloning theorem. Could somebody sketch this out?
N.B.: I have seen the argument that ...
- 1,544
3
votes
2
answers
510
views
Does entanglement harvesting require cooling the environment to sufficiently low temperatures?
I stumbled upon this webpage, which describe a process they call "entanglement harvesting". I was wondering whether to observe this effect it is necessary to cool the environment to ...
- 1,488
1
vote
1
answer
220
views
Is incompatibility required for contextuality?
A preprint just came out claiming that incompatibilty is not requried to demonstrate generalized contextuality. My question isn't about generalized contextuality---which I don't quite understand---but ...
- 1,325
1
vote
1
answer
162
views
Why are maximally entangled continuous variable states not physical?
I have been going through this paper: https://arxiv.org/abs/quant-ph/9908056
There in, just after eq (1), it's mentioned that maximally entangled continuous variable states are not physical. Why is ...
- 367
8
votes
0
answers
259
views
The emergence of space-time from entangled states
I recently read an article by Yasunori Nomura (https://arxiv.org/abs/1711.05263), in which he says that space-time is an emerging phenomenon. At the same time, space-time disappears when the ...
- 956
6
votes
4
answers
541
views
Changing the relative phase of two photons in an Hong-Ou-Mandel interference produces anti-bunching?
What happens to the output of a beam splitter when you change the relative phase between two photons that enter from the two input ports?
In Hong-Ou-Mandel interference for a beamsplitter of the form, ...
- 2,193
1
vote
1
answer
147
views
What is the form of a many-body hamiltonian that are subject to the measurement of the position?
Suppose there is a $N$ body hamiltonian, suppose $N=2$ for simplicity:
$$
H = - \frac{1}{2} \nabla_1^2 - \frac{1}{2} \nabla_2^2 + V(r_1,r_2) + \frac{1}{|r_1 - r_2|}.
$$
If we make a measurement for ...
- 1,356
14
votes
2
answers
2k
views
Implications of MIP*=RE for physics?
Background
Earlier this month (Jan 2020) a pre-print was posted to the arXiv claiming to have proved the equivalence of the complexity classes $\mathrm{MIP}^{*}$ and $\mathrm{RE}$ (see below for ...
- 1,330
3
votes
2
answers
279
views
Do "delayed choice" experiments send information back in time?
Consider the wave function collapse of a pair of entangled photons:
wave function is collapsed, let's call this state '0'
normal wave function, let's call this state '1'
In a "delayed choice" ...
- 395