Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Critical and strong-coupling phases in one- and two-bath spin-boson
  models   For phase transitions in dissipative quantum impurity models, the existence
of a quantum-to-classical correspondence has been discussed extensively. We
introduce a variational matrix product state approach involving an optimized
boson basis, rendering possible high-accuracy numerical studies across the
entire phase diagram. For the sub-ohmic spin-boson model with a power-law bath
spectrum $\propto \w^s$, we confirm classical mean-field behavior for $s<1/2$,
correcting earlier numerical renormalization-group results. We also provide the
first results for an XY-symmetric model of a spin coupled to two competing
bosonic baths, where we find a rich phase diagram, including both critical and
strong-coupling phases for $s<1$, different from that of classical spin chains.
This illustrates that symmetries are decisive for whether or not a
quantum-to-classical correspondence exists.

29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg