Struct MatrixProductState 

pub struct MatrixProductState { /* private fields */ }

Matrix Product State representation of an n-qubit pure state.

Implementations

impl MatrixProductState

pub fn new_zero_state(config: MpsConfig) -> QuantumResult<Self>

Build the product state |0…0⟩ with all bond dimensions equal to 1.

pub fn n_qubits(&self) -> usize

Number of qubits / sites.

pub fn config(&self) -> MpsConfig

The active configuration.

pub fn bond_dims(&self) -> Vec<usize>

The right-bond dimension of each site (one entry per site).

bond_dims()[k] is the dimension of the bond between site k and site k+1; the final entry is the right boundary bond (always 1).

pub fn apply_1q( &mut self, gate: &[[Complex<f32>; 2]; 2], qubit: usize, ) -> QuantumResult<()>

Apply a 1-qubit gate to qubit, contracting it into the physical index.

This leaves both bond dimensions unchanged.

pub fn apply_2q( &mut self, gate: &[[Complex<f32>; 4]; 4], q: usize, q_plus_1: usize, ) -> QuantumResult<()>

Apply a 4×4 two-qubit gate to adjacent qubits q and q+1.

The gate is indexed in the basis |q, q+1⟩ with q the more-significant of the two physical indices, i.e. the matrix row/column index is 2 * bit(q) + bit(q+1) — matching apply_2q_inplace.

Errors

Returns an error if the qubits are not adjacent with q_plus_1 == q + 1, or if either index is out of range.

pub fn to_statevector(&self) -> QuantumResult<StateVector>

Contract the whole chain into a dense 2^n StateVector.

Intended for verification on small systems; cost is exponential in n.

pub fn norm_sq(&self) -> f32

Squared norm ⟨ψ|ψ⟩ of the represented state.

pub fn norm(&self) -> f32

Euclidean norm ‖ψ‖.

pub fn normalize(&mut self)

Normalize the state in place (scales the first site tensor).

pub fn expectation_z(&self, qubit: usize) -> QuantumResult<f32>

Expectation value ⟨ψ| Z_qubit |ψ⟩.

Trait Implementations

impl Clone for MatrixProductState

fn clone(&self) -> MatrixProductState

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MatrixProductState

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.