Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quasi-excitations and superconductivity in the t-J model on a ladder   We study the t-J model on a ladder by using slave-fermion-CP^1 formalism
which is quite useful for study of lightly-doped high-T_c cuprates. By
integrating half of spin variables, we obtain a low-energy effective field
theory whose spin part is nothing but CP^1 sigma model. We especially focus on
dynamics of composite gauge field which determines properties of
quasi-excitations. Value of the coefficient of the topological term strongly
influences gauge dynamics and explaines why properties of quasi-excitations
depend on the number of legs of ladder. We also show that superconductivity
appears as a result of short-range antiferromagnetism and order parameter has
d-wave type symmetry.

8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc