RealMPS

Matrix Product State (MPS) of Real values. Compressed representation of a large-dimensional tensor, well suited for state vectors of some 1D many-body quantum mechanics problems.

Factories

make_random_mps(integer length, integer physical_size, integer bond_size, as_real as_real) -> RealMPS

Generate a random Matrix Product State (MPS) with Real values.

Parameters

• length: Number of sites in the MPS chain.
• physical_size: Dimension of the physical index at each site.
• bond_size: Maximum bond dimension between adjacent sites.
• as_real: The desired scalar type

Returns

A random RealMPS with the specified dimensions. Each site tensor has shape [bond_size, physical_size, bond_size].

Constructors

RealMPS(const RealMPS other) -> RealMPS

Copy constructor for Matrix Product State (MPS) of Real values.

Parameters

• other: MPS to copy.

RealMPS(integer length) -> RealMPS

Construct a Matrix Product State (MPS) of Real values with the specified number of sites.

Parameters

• length: Number of sites in the MPS chain.

Symbols

Name	Description
+	Compute the sum of two Matrix Product States (quantum states) with Real values.
=	Assignment operator for Matrix Product State (MPS) of Real values.
[]	Access a specific site tensor in the MPS chain by index. Supports negative indexing. :::tip Use the setter set_site if you want to modify the MPS. :::

Members

Name	Description
adjust_orthogonality_center	Update the orthogonality center position without modifying any tensors. Use this after manually transforming the MPS tensors in a way that changes the orthogonality center location.
compress	Compress the MPS by truncating the bond dimensions based on truncation options. Reduces the bond dimension according to the specified error measure and tolerance with Real values.
dot	Compute the inner product (overlap, dot product) between this MPS and another MPS.
get_orthogonality_center	Get the position of the orthogonality center in the MPS chain.
get_site	Get a copy of the site tensor at the specified index.
is_canonical	Check if the MPS is in canonical form (has a valid orthogonality center).
matrix_element	Compute the matrix element $\langle \text{bra} \| \hat{O} \| \text{ket} \rangle$ of a quantum operator between two MPS states with Real values.
max_bond	Get the maximum bond dimension across all bonds in the MPS chain.
normalize	Set the 2-norm of the MPS to one. Modifies the MPS in place.
normalized	Return a normalized copy of the MPS with 2-norm equal to one.
open_boundary	Set the MPS to open boundary conditions.
periodic_boundary	Set the MPS to periodic (closed) boundary conditions.
set_boundary_like	Copy the boundary conditions from another MPS or MPO.
set_orthogonality_center	Set the orthogonality center to a specific site. This brings the MPS into canonical form with all tensors to the left in left-canonical form and all tensors to the right in right-canonical form.
set_site	Set the site tensor at the specified index.
size	Get the number of sites in the MPS chain.
unset_orthogonality_center	Remove the orthogonality center, marking the MPS as non-canonical. :::tip The MPS content is not modified by this method.:::