Quantum-inspired tensor network simulator of quantum computers and method associated therewith

A computer-implemented method for simulating a quantum computer or a quantum circuit thereof, the method comprising:

• reading at least some two-qubit terms of the quantum circuit of the quantum computer;
• selecting a read two-qubit term and providing a two-qubit gate such that:
• a tensor per qubit is provided, and
• a connecting tensor index for the provided two tensors is provided between them;
• shortening the connecting tensor index by using a value decomposition and keeping a predetermined number D of largest values;
• when a number of connecting tensor indices of a resulting tensor network is greater that a predetermined threshold M, removing at least as many connecting tensor indices as needed to reduce the number of connecting tensor indices down to the predetermined threshold M;
• and
• repeating the selecting, shortening and removing steps for all other read two-qubit terms.

A method comprising:

• simulating an existing quantum computer or quantum circuit thereof by running a computer-implemented method comprising:
• reading at least some two-qubit terms of the quantum circuit of the quantum computer;
• selecting a read two-qubit term and providing a two-qubit gate such that:
• a tensor per qubit is provided, and
• a connecting tensor index for the provided two tensors is provided between them;
• shortening the connecting tensor index by using a value decomposition and keeping a predetermined number D of largest values;
• when a number of connecting tensor indices of a resulting tensor network is greater that a predetermined threshold M, removing at least as many connecting tensor indices as needed to reduce the number of connecting tensor indices down to the predetermined threshold M;
• and
• repeating the selecting, shortening and removing steps for all other read two-qubit terms;
• assessing limitations in operation of the existing quantum computer or quantum circuit with the simulation performed;
• and
• manufacturing a quantum computer or quantum circuit thereof at least based on the assessed limitations.