Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ballistic-hydrodynamic phase transition in flow of two-dimensional
  electrons   Phase transitions are characterized by a sharp change in the type of dynamics
of microparticles, and their description usually requires quantum mechanics.
Recently, a peculiar type of conductors was discovered in which two-dimensional
(2D) electrons form a viscous fluid. In this work we reveal that such electron
fluid in high-quality samples can be formed from ballistic electrons via a
phase transition. For this purpose, we theoretically study the evolution of a
ballistic flow of 2D weakly interacting electrons with an increase of magnetic
field and trace an emergence of a fluid fraction at a certain critical field.
Such restructuring of the flow manifests itself in a kink in magnetic-field
dependencies of the longitudinal and the Hall resistances. It is remarkable
that the studied phase transition has a classical-mechanical origin and is
determined by both the ballistic size effects and the electron-electron
scattering. Our analysis shows that this effect was apparently observed in the
recent transport experiments on 2D electrons in graphene and high-mobility GaAs
quantum wells.

22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
1
The categories of this paper are: cs
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int