Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Competing phases in spin-1/2 J1-J2 chain with easy-plane anisotropy   We summarize our theoretical findings on the ground-state phase diagram of
the spin-1/2 XXZ chain having competing nearest-neighbor (J1) and
antiferromagnetic next-nearest-neighbor (J2) couplings. Our study is mainly
concerned with the case of ferromagnetic J1, and the case of antiferromagnetic
J1 is briefly reviewed for comparison. The phase diagram contains a rich
variety of phases in the plane of J1/J2 versus the XXZ anisotropy Delta:
vector-chiral phases, N\'eel phases, several dimer phases, and
Tomonaga-Luttinger liquid phases. We discuss the vector-chiral order that
appears for a remarkably wide parameter space, successive N\'eel-dimer phase
transitions, and an emergent nonlocal string order in a narrow region of
ferromagnetic J1 side.

25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org