qat.mps

qat.mps includes all the necessary tools for simulating quantum states using matrix-product representations. We provide QPUs for both matrix product states (MPS) simulations for noiseless systems, as well as matrix product operator (MPO) simulations for noisy systems. We also provide lower level tools for computing and using your own MPS and MPO.

Computing tensor networks

`qat.mps.compute_mpo()`	Compute an MPO for a given quantum circuit
`qat.mps.compute_mps()`	Compute an MPS for a given quantum circuit

Tensor network methods for MPO

`qat.mps.mpo.StateMPO.contract()`	Contract a quantum state in MPO representation back to its density matrix representation
`qat.mps.mpo.StateMPO.expectation_value()`	Compute the expectation value of an observable on the MPO
`qat.mps.mpo.StateMPO.get_memory_used()`	Check memory usage of the MPO
`qat.mps.mpo.StateMPO.load()`	Load an MPO from a file
`qat.mps.mpo.StateMPO.sample()`	Sample an MPO probability for a given bitstring
`qat.mps.mpo.StateMPO.save()`	Save an MPO as a file
`qat.mps.mpo.StateMPO.trace()`	Compute the trace of the MPO

Tensor network methods for MPS

`qat.mps.mps.StateMPS.contract()`	Contract a quantum state in MPS representation back to its statevector representation
`qat.mps.mps.StateMPS.expectation_value()`	Compute the expectation value of an observable on the MPS
`qat.mps.mps.StateMPS.get_memory_used()`	Check memory usage of the MPS
`qat.mps.mps.StateMPS.load()`	Load an MPS from a file
`qat.mps.mps.StateMPS.norm()`	Compute the norm of the MPS
`qat.mps.mps.StateMPS.sample()`	Sample an MPS probability for a given bitstring
`qat.mps.mps.StateMPS.save()`	Save an MPS as a file

Tools for random circuit studies

`qat.mps.random_circuits.cheng_random_circuit()`	Generate random circuit Program used by Cheng et al. (2021)
`qat.mps.random_circuits.random_circuit_generator()`	Generate a random circuit with 2 qubits Haar-random generated gates
`qat.mps.random_circuits.random_gate_generator()`	Generate Haar-random quantum gate of given arity
`qat.mps.random_circuits.random_observable()`	Generate a random observable