Questions tagged [quantum-discord]
For questions about the quantum discord, a form of nonclassicality due to the possibly non-accessible nature of the quantum mutual information.
4
questions with no upvoted or accepted answers
3
votes
0
answers
94
views
How to calculate Quantum Discord for two qubit system using Qutip?
Quantum discord of a bipartite system can be determined as:
$${D_A}({\rho _{AB}}) = I({\rho _{AB}}) - {J_A}({\rho _{AB}}),$$
The subscript of $A$ denotes that the measurement has been performed on the ...
- 131
2
votes
0
answers
40
views
What are examples where the quantum discord is achieved by a non-projective POVM?
Consider the (asymmetric) quantum discord, defined as (borrowing notation from Eq. 4.13c of Zurek's review):
$$\mathcal D(\mathcal S:\mathcal A) = I(\mathcal S:\mathcal A) - \chi(\rho_{\mathcal A}),$$
...
glS♦
- 21.7k
2
votes
0
answers
54
views
Can't understand how $D_{A,B} + D_{A,C} \ge E_{A,B}+E_{A,C}$ is proved used the subadditivity of entropy
I am reading Monogamy properties of quantum and classical correlations. Eq.10 states that $$D_{A,B} + D_{A,C} \ge E_{A,B}+E_{A,C},$$ where $D_{i,j}$ is the quantum discord, and $E_{A,B}$ is the ...
- 1,097
2
votes
0
answers
400
views
What does a quantum mutual information larger than its classical upper bound represent?
Let $\rho$ be a bipartite state. Its quantum mutual information is defined as
$$\newcommand{\tr}{\operatorname{tr}}I(\rho) = S(\tr_B(\rho)) + S(\tr_A(\rho)) - S(\rho),$$
where $S(\sigma)$ is the von ...
glS♦
- 21.7k