Struct MPS 

pub struct MPS {
    pub tensors: Vec<Tensor>,
    pub n_sites: usize,
    pub phys_dim: usize,
    pub max_bond_dim: usize,
}

Matrix Product State (MPS) representation.

Each tensor at site i has shape [bond_left, phys_dim, bond_right]. At the boundaries: bond_left = 1 at site 0, bond_right = 1 at site n-1.

Fields

tensors: Vec<Tensor>

Site tensors: tensors[i] has shape [D_l, d, D_r]

n_sites: usize

Number of sites

phys_dim: usize

Physical dimension (e.g. 2 for a spin-1/2 chain)

max_bond_dim: usize

Maximum allowed bond dimension (for compression)

Implementations

impl MPS

pub fn product_state(values: &[usize], phys_dim: usize) -> QcResult<Self>

Create an MPS for a computational basis product state |v_1 v_2 … v_n⟩.

Each site tensor has shape [1, phys_dim, 1] with a single non-zero entry.

pub fn bond_dim_left(&self, site: usize) -> usize

Left bond dimension at site i (= tensors[i].shape[0])

pub fn bond_dim_right(&self, site: usize) -> usize

Right bond dimension at site i (= tensors[i].shape[2])

pub fn overlap(&self, other: &MPS) -> QcResult<f64>

Compute ⟨self|other⟩ by left-to-right contraction.

Returns the overlap (should be real for normalized MPS).

pub fn norm(&self) -> QcResult<f64>

Compute the norm ‖|ψ⟩‖ = sqrt(⟨ψ|ψ⟩).

pub fn normalize(&mut self) -> QcResult<()>

Normalize the MPS in-place by dividing the first tensor by the norm.

If the norm is smaller than the threshold, the MPS is reset to the all-zero product state and a warning is recorded (normalization is skipped).

Trait Implementations

impl Clone for MPS

fn clone(&self) -> MPS

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MPS

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

Formats the value using the given formatter.