Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Phase Transition between (Luttinger) Liquid and Gas of Cold
  Molecules   We consider cold polar molecules confined in a helical optical lattice
similar to those used in holographic microfabrication. An external electric
field polarizes molecules along the axis of the helix. The large-distance
inter-molecular dipolar interaction is attractive but the short-scale
interaction is repulsive due to geometric constraints and thus prevents
collapse. The interaction strength depends on the electric field. We show that
a zero-temperature second-order liquid-gas transition occurs at a critical
field. It can be observed under experimentally accessible conditions.

14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th