Questions tagged [entanglement-entropy]
56 questions
18
votes
2 answers
Interpreting the Quantum Fisher Information
I recently saw this article in Nature Physics regarding Quantum Fisher Information (QFI):
http://www.nature.com/nphys/journal/v12/n8/full/nphys3700.html
Frankly I have not been following Quantum Information for a number of years now, and have never…
KF Gauss
- 8,314
9
votes
1 answer
Quantum field theory text on entanglement entropy
I am looking for a quantum field theory book in which entanglement entropy for quantum fields is explained but I can not find such a book. Is there such a book?
user2020
- 1
8
votes
1 answer
What information does the Von Neumann entropy give for mixed states?
Von Neumann entropy is defined as
$$
S=-\mathrm{Tr}\left(\rho \ln\rho\right)
$$
It can be used to measure the entanglement between two sub-systems, provided that the total system is in pure state.
1) What information does the Von Neumann entropy…
AndreaPaco
- 1,322
7
votes
2 answers
The expectation value of entanglement entropy of composite system in a random pure state
I'm trying to compute the expectation value of entanglement entropy of composite system in a random pure state, but I'm running into some problems.
The system we are considering is composed of two subsystems $\mathcal{H} = \mathcal{H}_A \otimes…
Lagrangian
- 365
- 2
- 15
6
votes
0 answers
What is a maximally entangled state? Or better, what really is entanglement entropy?
I was trying to understand the concept of entanglement entropy and for that I was studying the density operator formalism in the context of a bipartite quantum system.
In some references, people define the maximally entangled state as the one whose…
blackhole1511
- 531
6
votes
1 answer
Entanglement between the electrons in the Laughlin wave function
Consider the $1/3$-Laughlin wave function
$$ \Psi \propto \exp \left(-\sum_i |z_i|^2 \right) \prod_{1\leq i
Jiang-min Zhang
- 4,262
5
votes
0 answers
Heat kernel expansion for entanglement entropy
Can somebody please let me know where I can find a reference for calculating heat kernel coefficients on a manifold with conical singularities? I am trying to compute the entanglement entropy for gauge fields using the heat kernel and the conical…
user28209
- 151
5
votes
0 answers
Types of entropy
As I understand, entropy was first introduced as a state function of a macroscopic system, based on observations such as those of Clausius and Kelvin, pertaining to the directionality of spontaneous processes. Then Boltzmann introduced the idea of…
Meep
- 4,167
5
votes
0 answers
Entanglement inequality (Gaussian vs. non-Gaussian states)
I'm considering a quantum system with $N$ bosonic degrees of freedom labelled by pairs $(x^i,p^i)$, such that the Hilbert space is $\mathcal{H}=L^2(\mathbb{R}^N)$. Given an arbitrary quantum state $|\psi\rangle$, I can compute its 2-point…
LFH
- 760
5
votes
0 answers
Geometric measure of entanglement for fermions or bosons?
For a system consisting of multiple components, say, a spin chain consisting of $N\geq 3 $ spins, people sometimes use the so-called geometric measure of entanglement. It is related to the inner product between the wave function and a simple tensor…
kaiser
- 1,227
5
votes
2 answers
Why does the topological entropy scale with $\log(L)$ in 1D?
Why, in one dimension, does the topological entropy scale with the size of system as $S \sim \ln L$, while in a 2D system it scales with $S \sim L$? Why does dimensionality play such an important role here? I mean, is there any simple but…
Ming Gong
- 209
4
votes
1 answer
why entanglement entropy is important in topological phases？
When mentioning interacting topological phases people always talk about entanglement entropy.
why it is important?
what is its physical meaning?
Vivian
- 487
4
votes
1 answer
Distinction between holographic entanglement entropy and thermal entropy
Given a system $A$ and its complement $\bar{A}$, we know that the entanglement entropy is given by
$$ S_A = - \text{Tr} ( \rho_A \log \rho_A ), $$
where $\rho_A$ is the reduced density matrix obtained by tracing out the degrees of freedom in…
physguy
- 679
4
votes
0 answers
Merger of old black holes
On the eve of a possible announcement on the production of gravitational waves via a black hole merger, I think this question is quite aptly timed. I have a few questions regarding the evolution of the entanglement entropy of black holes
How does…
user106422
4
votes
0 answers
Generalized gravitational entropy and entanglement entropy
What are the differences (if any) between Generalized gravitational entropy (Lewkowycz-Maldacena) and holographic entanglement entropy (Ryu-Takayanagi)?
More specifically, I was wondering following the same procedure in the appendix A of…
Physics Moron
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