Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum spin nanotubes -- frustration, competing orders and
  criticalities   Recent developments of theoretical studies on spin nanotubes are reviewed,
especially focusing on the $S=1/2$ three-leg spin tube. In contrast to the
three-leg spin ladder, the tube has a spin gap in case of the regular-triangle
unit cellwhen the rung interaction is sufficiently large. The effective theory
based on the Hubbard Hamiltonian indicates a quantum phase transition to the
gapless spin liquid due to the lattice distortion to an isosceles triangle.
This is also supported by the numerical diagonalization and the density matrix
renormalization group analyses. Furthermore, combining analytical and numerical
approaches, we reveal several novel magnetic-field-induced phenomena: N\'eel,
dimer, chiral and/or inhomogeneous orders, new mechanism for the magnetization
plateau formation,and others. The recently synthesized spin tube materials are
also briefly introduced.

35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an