atlas_q.quantum_hybrid_system.MatrixProductState#

class atlas_q.quantum_hybrid_system.MatrixProductState(num_qubits, bond_dim=8)[source]#

Tensor network representation for moderate entanglement Memory: O(n × χ²) where χ is bond dimension

Can simulate 50-100 qubits with controlled entanglement!

NEW: MPS canonicalization and sweep sampling for accurate measurements

Methods

`canonicalize_left_to_right`()	Bring MPS into left-canonical form using QR decomposition
`canonicalize_right_to_left`()	Bring MPS into right-canonical form using QR decomposition
`get_amplitude`(basis_state)	Contract MPS to get amplitude - O(n × χ²)
`get_probability`(basis_state)	Get measurement probability for a basis state
`measure`([num_shots])	Simulate measurement with accurate MPS sampling
`memory_usage`()	Memory usage in bytes
`sweep_sample`([num_shots])	Accurate MPS sampling using conditional probabilities sweep

__init__(num_qubits, bond_dim=8)[source]#

Methods

`__init__`(num_qubits[, bond_dim])
`canonicalize_left_to_right`()	Bring MPS into left-canonical form using QR decomposition
`canonicalize_right_to_left`()	Bring MPS into right-canonical form using QR decomposition
`get_amplitude`(basis_state)	Contract MPS to get amplitude - O(n × χ²)
`get_probability`(basis_state)	Get measurement probability for a basis state
`measure`([num_shots])	Simulate measurement with accurate MPS sampling
`memory_usage`()	Memory usage in bytes
`sweep_sample`([num_shots])	Accurate MPS sampling using conditional probabilities sweep

canonicalize_left_to_right()[source]#

Bring MPS into left-canonical form using QR decomposition

Each tensor satisfies: Σₛ Aˢ†Aˢ = I (left-orthogonal) This enables efficient sampling and norm computation!

canonicalize_right_to_left()[source]#

Bring MPS into right-canonical form using QR decomposition

Each tensor satisfies: Σₛ AˢAˢ† = I (right-orthogonal)

sweep_sample(num_shots=1)[source]#

Accurate MPS sampling using conditional probabilities sweep

This is the CORRECT way to sample from MPS! Complexity: O(num_shots × n × χ²)

measure(num_shots=1)[source]#

Simulate measurement with accurate MPS sampling

Uses sweep sampling for correct probability distribution

get_amplitude(basis_state)[source]#

Contract MPS to get amplitude - O(n × χ²)

memory_usage()[source]#

Memory usage in bytes