Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Identical Spin Rotation Effect and Electron Spin Waves in Quantum Gas of
  Atomic Hydrogen   We present an experimental study of electron spin waves in atomic hydrogen
gas compressed to high densities of $\sim 5 \times 10^{18}$ cm$^{-3}$ at
temperatures ranging from 0.26 to 0.6 K in strong magnetic field of 4.6 T.
Hydrogen gas is in a quantum regime when the thermal de Broglie wavelength is
much larger than the s-wave scattering length. In this regime the identical
particle effects play major role in atomic collisions and lead to the Identical
Spin Rotation effect (ISR). We observed a variety of spin wave modes caused by
this effect with strong dependence on the magnetic potential caused by
variations of the polarizing magnetic field. We demonstrate confinement of the
ISR modes in the magnetic potential and manipulate their properties by changing
the spatial profile of magnetic field. We have found that at a high enough
density of H gas the magnons accumulate in their ground state in the magnetic
trap and exhibit long coherence, which has a profound effect on the electron
spin resonance spectra. Such macroscopic accumulation of the ground state
occurs at a certain critical density of hydrogen gas, where the chemical
potential of the magnons becomes equal to the energy of their ground state in
the trapping potential.

22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio