issp-center-dev / TeNeS

Massively parallel tensor network solver
http://www.pasums.issp.u-tokyo.ac.jp/tenes/en
GNU General Public License v3.0
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Onesite Hamiltonians and ITE #56

Closed yomichi closed 1 year ago

yomichi commented 1 year ago

So far, the whole Hamiltonian is divided as the summation of bond Hamiltonians and all the imaginary time evolutional tensors operate on bond, and therefore onsite terms such as Zeeman terms should be absorbed into bond Hamiltonians. In the PR, I implemented one site imaginary time evolutional tensors in tenes, and site Hamiltonians can be used in input files of tenes_std.

An example of site Hamiltonian in std.toml:

[[hamiltonian]]
dim = [2]
sites = []
elements = """
0 0 -1.25 0.0
1 1 1.25 0.0
"""

and an example of site ITE tensor in input.toml:

[[evolution.simple]]
site = 0
dimensions = [2, 2]
elements = """
0 0  1.0125784515406344 0.0
1 1  0.9875778004938814 0.0
"""

Additionally, I added a new option of tenes_simple, --use-site-hamiltonian, in order to generate site Hamiltonians.