Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Toward computability of trace distance discord   It is known that a reliable geometric quantifier of discord-like correlations
can be built by employing the so-called trace distance. This is used to measure
how far the state under investigation is from the closest "classical-quantum"
one. To date, the explicit calculation of this indicator for two qubits was
accomplished only for states such that the reduced density matrix of the
measured party is maximally mixed, a class that includes Bell-diagonal states.
Here, we first reduce the required optimization for a general two-qubit state
to the minimization of an explicit two-variable function. Using this framework,
we show next that the minimum can be analytically worked out in a number of
relevant cases including quantum-classical and X states. This provides an
explicit and compact expression for the trace distance discord of an arbitrary
state belonging to either of these important classes of density matrices.

16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat