Workspace object for taking snapshots from matrix-product State. More...

#include <snapshots.h>

Collaboration diagram for syten::MPS::Snapshots::Workspace:

Classes
struct	SSM
	Structure representing single-site measurement subspace-projector and eigenvalue as well as probability to measure outcome. More...

Public Member Functions
std::vector< SSM >	get_last_ssm_decomposition () const
	Return last sso decomposition. More...

State &	get_state ()
	Get state. More...

SRDef	measure_sso (const Lattice &_lattice, const std::string &_sso, const Index &_site)
	Measure single-site operator and collapse tensor at given site. More...

std::vector< SRDef >	measure_ssos (const Lattice &_lattice, const std::string &_sso)
	Measure single-site operator at every site and collapse state. More...

void	set_state (const State &_state)
	Set state and reset workspace. More...

	Workspace (const Index _seed=0)
	Constructor initializing workspace, if seed > 0 then random number generator is initialized (see Random::initReproducible) More...

	Workspace (const State &_psi, const Index _seed=0)
	Constructor initializing workspace with state, if seed > 0 then random number generator is initialized (see Random::initReproducible) More...

Protected Member Functions
void	decompose_sso (const Lattice &_lattice, const std::string &_sso_id, const Index &_site, std::vector< SSM > &_result)
	Decomposes single-site operator into projectors to eigenspaces and eigenvalues. More...

std::vector< SSM >::const_iterator	draw_ssm_sample (const std::vector< SSM > &_ssm_decomposition)
	Sample single-site measurement. More...

void	move_to_site (const Index &_site)
	Move center of orthogonality to site. More...

Protected Attributes
State	psi
	The state. More...

Private Attributes
bool	full_normalize
	Flag to decide if full normalization sweep is required. More...

Random::Engine	gen
	Random number generator. More...

std::vector< SSM >	last_ssm_decomposition
	Store last sso decomposition. More...

Index	last_visited
	Store last collapsed site. More...

Detailed Description

Workspace object for taking snapshots from matrix-product State.

Object of this class wraps snapshot operations acting on MPS. The state can be collapsed both, either partially or completely while performing projective measurements, emulating snapshot experiments. After a snapshot measurement w.r.t. to an observable \(\hat O\) on a site with measurement outcome \(\O_alpha\), the corresponding site tensor is uncorrelated with the remaining site tensors and represents the eigenstate \(\ket{\alpha}\) of the measurement operator belonging to the measurement outcome. This way, perfect sampling can be realized by subsequently collapsing sites, drawing the measurement outcome probabilities from the correct, conditional joint probability distribution.

Note that the workspace object creates a copy of the input state on creation.

The documentation for this class was generated from the following files:

inc/mps/snapshots.h
inc/mps/snapshots.cpp

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Private Attributes

Detailed Description