Linalg – Useful linear algebra functions for QM

squanch.linalg.is_hermitian(matrix)

Checks if an operator is Hermitian

Parameters:matrix (np.array) – the operator to check Returns:true or false

squanch.linalg.tensor_product(state1, state2)

Returns the Kronecker product of two states

Parameters:

• state1 (np.array) – the first state
• state2 (np.array) – the second state

Returns:

the tensor product

squanch.linalg.tensors(operator_list)

Returns the iterated Kronecker product of a list of states

Parameters:operator_list ([np.array]) – list of states to tensor-product Returns:the tensor product

squanch.linalg.tensor_fill_identity(single_qubit_operator, n_qubits, qubit_index)

Create the n-qubit operator I x I x … Operator x I x I… with operator applied to a given qubit index

Parameters:

• single_qubit_operator (np.array) – the operator in the computational basis (a 2x2 matrix)
• n_qubits (int) – the number of qubits in the system to fill
• qubit_index (int) – the zero-indexed qubit to apply this operator to

Returns:

the n-qubit operator