Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tree tensor networks and entanglement spectra   A tree tensor network variational method is proposed to simulate quantum
many-body systems with global symmetries where the optimization is reduced to
individual charge configurations. A computational scheme is presented, how to
extract the entanglement spectra in a bipartite splitting of a loopless tensor
network across multiple links of the network, by constructing a matrix product
operator for the reduced density operator and simulating its eigenstates. The
entanglement spectra of 2 x L, 3 x L and 4 x L with either open or periodic
boundary conditions on the rungs are studied using the presented methods, where
it is found that the entanglement spectrum depends not only on the subsystem
but also on the boundaries between the subsystems.

15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ