Tagged Questions
1
vote
1answer
32 views
Name of a state with $d-1$ excitations, distributed uniformly among $n$ qudits
Is there a particular name for a quantum state of the form (up to the normalization):
$$\sum_{i_1+\ldots+i_n = d-1} |i_1\rangle |i_2\rangle \ldots |i_n\rangle$$
or was it studied is some papers?
...
5
votes
0answers
113 views
Local explanation of the Aharonov-Bohm effect in terms of force fields
Here is an interesting paper for the Physics SE community: On the role of potentials in the Aharonov-Bohm effect, Lev Vaidman, published in PHYSICAL REVIEW A 86, 040101(R) (2012).
You should check it ...
10
votes
4answers
545 views
Is there an intuitive description of vacuum entanglement?
People often refer to the fact that the vacuum is an entangled state (It's even described as a maximally entangled state).
I was trying to get a feeling for what that really means. The problem is ...
7
votes
1answer
565 views
Is resonating valence bond (RVB) states long-range entangled?
Quantum liquid is at the core of condensed matter theory study, examples include superfluid in Bose Hubbard model, quantum spin liquid around the RK point of a quantum dimer model, string-net ...
10
votes
1answer
452 views
Entanglement in time
Quantum entanglement links particles through time, according to this study that received some publicity last year:
New Type Of Entanglement Allows 'Teleportation in Time,' Say Physicists at The ...
9
votes
1answer
155 views
Reduced density matrices for free fermions are thermal
Many recent papers study entanglement in eigenstates of fermionic free hamiltonians (normally on a lattice) using the basic assumption that the reduced density matrices are thermal (e.g. Peschel ...
3
votes
2answers
96 views
Do any entanglement measures for mixed states exist that use only single site correlation functions?
For a pure state $\rho_{AB}$, the entropy of entanglement of subsystem $A$ is
\begin{equation}
S( \rho_A) = -tr (\rho_A \log \rho_A)
\end{equation}
where $\rho_A$ is the reduced density matrix of A. ...
5
votes
1answer
37 views
Optimality of the CHSH strategy
The maximum achievable probability of the Clauser-Horne-Shimony-Holt game is $\cos^2(\pi/8)\approx85.355\%,$ which can be proved with Tsirelson's inequality. But I don't imagine that this remained ...
11
votes
1answer
81 views
CHSH violation and entanglement of quantum states
How is the violation of the usual CHSH inequality by a quantum state related to the entanglement of that quantum state?
Say we know that exist Hermitian and unitary operators $A_{0}$, $A_{1}$, ...
4
votes
1answer
324 views
A physical understanding of fractionalization
all! Is there a physical understanding of fractionalization in condensed matter physics? The textbook approach is theoretical, not physical. I'm thinking of spin-charge separation for electrons, the ...
17
votes
2answers
89 views
What Shannon channel capacity bound is associated to two coupled spins?
The question asked is:
What is the Shannon channel capacity $C$ that is naturally associated to the two-spin quantum Hamiltonian $H = \boldsymbol{L\cdot S}$?
This question arises with a view ...
19
votes
1answer
280 views
State of Matrix Product States
What is a good summary of the results about the correspondence between matrix product states (MPS) or projected entangled pair states (PEPS) and the ground states of local Hamiltonians? Specifically, ...
13
votes
2answers
158 views
A resource theory of quantum discord?
Local Operations and Classical Communication (LOCC) is the classic paradigm for studying entanglement. These are things that are `cheap' and unable to produce entanglement as a resource for a quantum ...
14
votes
0answers
176 views
Orbits of maximally entangled mixed states
It is well known (Please, see for example Geometry of quantum states by Bengtsson and Życzkowski ) that the set of $N-$dimensional density matrices is stratified by the adjoint action of $U(N)$, where ...
8
votes
1answer
23 views
Sub and super multiplicativity of norms for understanding non-locality
In relation to various problems in understanding entanglement and non-locality, I have come across the following mathematical problem. It is most concise by far to state in its most mathematical form ...
