Getting Started

Installation

To get started, first install the project using pip

pip install acetn

If Ace-TN is already installed, upgrade to the latest version with

pip install --upgrade acetn

Alternatively, install from GitHub with

pip install git+https://github.com/ace-tn/ace-tn

Quickstart

After installation, we are ready to build an iPEPS. If running in CPU mode, we recommend specifying the number of threads used by setting one of the following environment variables, depending on your hardware setup, before getting started. For example:

export MKL_NUM_THREADS=4
export OMP_NUM_THREADS=4

Create a basic input.toml file to specify the iPEPS simulation config

dtype = "float64"
device = "cuda"

[TN]
nx = 2
ny = 2

[TN.dims]
phys = 2
bond = 4
chi = 16

[model]
name = "heisenberg"

[model.params]
J = 1.0

This input can then be used to instantiate an iPEPS on the GPU with FP64 data type, physical dimension d=2, bond dimension D=4, boundary bond dimension chi=16, and AFM Heisenberg as the target model. The iPEPS is then instantiated with

from acetn.ipeps import Ipeps
import toml

config = toml.load("input.toml")
ipeps = Ipeps(config)

The basic workflow of an iPEPS ground-state including imaginary-time evolution and measurement can be executed with

ipeps.evolve(dtau=0.01, steps=500)
measurements = ipeps.measure()

For more detailed examples demontrating usage including custom model construction, see the Examples section.