Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Many-body interactions in a quantum wire in the integer quantum Hall
  regime: suppression of exchange-enhanced g factor   The collapse of Hall gaps in the integer quantum Hall liquid in a quantum
wire is investigated. Motivated by recent experiment [Pallecchi et al. PRB 65,
125303 (2002)] previous approaches are extended to treat confinement effects
and the exchanged enhanced g-factor in quantum wires. Two scenarios for the
collapse of the $\nu =1$ state are discussed. In the first one the $\nu =1$
state becomes unstable at $B_{cr}^{(1)}$, due to the exchange interaction and
correlation effects, coming from the edge-states screening. In the second
scenario, a transition to the $\nu =2$ state occurs at $B_{cr}^{(2)}$, with a
smaller effective channel width, caused by the redistribution of the charge
density. This effect turns the Hartree interaction essential in calculating the
total energy and changes $B_{cr}^{(2)}$ drastically. In both scenarios, the
exchange enhanced g-factor is suppressed for magnetic fields lower than
$B_{cr}$. Phase diagrams for the Hall gap collapse are determined. The critical
fields, activation energy, and optical $g$-factor obtained are compared with
experiments. Within the accuracy of the available data, the first scenario is
most probable to be realized.

17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom