Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quasi-classical determination of the in-plane magnetic field phase
  diagram of superconducting Sr_2RuO_4   We have carried out a determination of the magnetic-field-temperature (H-T)
phase diagram for realistic models of the high field superconducting state of
tetragonal Sr_2RuO_4 with fields oriented in the basal plane. This is done by a
variational solution of the Eilenberger equations.This has been carried for
spin-triplet gap functions with a {\bf d}-vector along the c-axis (the chiral
p-wave state) and with a {\bf d}-vector that can rotate easily in the basal
plane. We find that, using gap functions that arise from a combination of
nearest and next nearest neighbor interactions, the upper critical field can be
approximately isotropic as the field is rotated in the basal plane. For the
chiral {\bf d}-vector, we find that this theory generically predicts an
additional phase transition in the vortex state. For a narrow range of
parameters, the chiral {\bf d}-vector gives rise to a tetracritical point in
the H-T phase diagram. When this tetracritical point exists, the resulting
phase diagram closely resembles the experimentally measured phase diagram for
which two transitions are only observed in the high field regime. For the
freely rotating in-plane {\bf d}-vector, we also find that additional phase
transition exists in the vortex phase. However, this phase transition
disappears as the in-plane {\bf d}-vector becomes weakly pinned along certain
directions in the basal plane.

35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph