Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gradient critical phenomena in the Ising quantum chain   We consider the behaviour of a critical system in the presence of a gradient
perturbation of the couplings. In the direction of the gradient an interface
region separates the ordered phase from the disordered one. We develop a
scaling theory for the density profiles induced by the gradient perturbation
which involves a characteristic length given by the width of the interface
region. The scaling predictions are tested in the framework of the mean-field
Ginzburg-Landau theory. Then we consider the Ising quantum chain in a linearly
varying transverse field which corresponds to the extreme anisotropic limit of
a classical two-dimensional Ising model. The quantum Hamiltonian can be
diagonalized exactly in the scaling limit where the eigenvalue problem is the
same as for the quantum harmonic oscillator. The energy density, the
magnetization profile and the two-point correlation function are studied either
analytically or by exact numerical calculations. Their scaling behaviour are in
agreement with the predictions of the scaling theory.

10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an