Physics

Tensor contraction

Maximum bubble pressure method

Tensor (intrinsic definition)

Operator (biology)

Pure mathematics

Mathematics

Transcription factor

Gene

Interface (matter)

Optics

Matrix (chemical analysis)

Algebra over a field

Tensor density

Bubble

Mathematical analysis

Matrix multiplication

Parallel computing

Repressor

Composite material

Tensor field

Chemistry

Focus (optics)

Materials science

Computer science

Tensor product

Exact solutions in general relativity

Quantum mechanics

Theoretical computer science

Computational science

Biochemistry

Cartesian tensor

Quantum

SciPost Physics Codebases

ITensor is a system for programming tensor network calculations with an interface modeled on tensor diagrams, allowing users to focus on the connectivity of a tensor network without manually bookkeeping tensor indices. The ITensor interface rules out common programming errors and enables rapid prototyping of algorithms. After discussing the philosophy behind the ITensor approach, we show examples of each part of the interface including Index objects, the ITensor product operator, tensor factorizations, tensor storage types, algorithms for matrix product state (MPS) and matrix product operator (MPO) tensor networks, quantum number conserving block sparse tensors, and the NDTensors library. We also review publications that have used ITensor for quantum many-body physics and for other areas where tensor networks are increasingly applied. To conclude we discuss promising features and optimizations to be added in the future.

The ITensor Software Library for Tensor Network Calculations