Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Entangled Mechanical Oscillators   Hallmarks of quantum mechanics include superposition and entanglement. In the
context of large complex systems, these features should lead to situations like
Schrodinger's cat, which exists in a superposition of alive and dead states
entangled with a radioactive nucleus. Such situations are not observed in
nature. This may simply be due to our inability to sufficiently isolate the
system of interest from the surrounding environment -- a technical limitation.
Another possibility is some as-of-yet undiscovered mechanism that prevents the
formation of macroscopic entangled states. Such a limitation might depend on
the number of elementary constituents in the system or on the types of degrees
of freedom that are entangled. One system ubiquitous to nature where
entanglement has not been previously demonstrated is distinct mechanical
oscillators. Here we demonstrate deterministic entanglement of separated
mechanical oscillators, consisting of the vibrational states of two pairs of
atomic ions held in different locations. We also demonstrate entanglement of
the internal states of an atomic ion with a distant mechanical oscillator.

30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math