Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evidence for a Self-Bound Liquid State and the
  Commensurate-Incommensurate Coexistence in 2D $^3$He on Graphite   We made heat-capacity measurements of two dimensional (2D) $^3$He adsorbed on
graphite preplated with monolayer $^4$He in a wide temperature range (0.1 $\leq
T \leq$ 80 mK) at densities higher than that for the 4/7 phase (= 6.8
nm$^{-2}$). In the density range of 6.8 $\leq \rho \leq$ 8.1 nm$^{-2}$, the 4/7
phase is stable against additional $^3$He atoms up to 20% and they are promoted
into the third layer. We found evidence that such promoted atoms form a
self-bound 2D Fermi liquid with an approximate density of 1 nm$^{-2}$ from the
measured density dependence of the $\gamma$-coefficient of heat capacity. We
also show evidence for the first-order transition between the commensurate 4/7
phase and the ferromagnetic incommensurate phase in the second layer in the
density range of 8.1 $\leq \rho \leq$ 9.5 nm$^{-2}$.

16
The categories of this paper are: stat
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin