Detailed Description

Implements the Hamiltonian for the J1-J2 XY model on the square lattice.

Options Database
Command line argument	Description
`-Lx [int]`	lattice dimension in the longitudinal direction (growing) [def: 4]
`-Ly [int]`	lattice dimension in the transverse direction [def: 4]
`-J1 [float]`	coupling constant for the nearest neighbor interaction
`-Jz1 [float]`	anisotropy in the z-direction for the nearest neighbor interaction
`-J2 [float]`	coupling constant for the next-nearest neighbor interaction
`-Jz2 [float]`	anisotropy in the z-direction for the next-nearest neighbor interaction
`-heisenberg [float]`	Overrides other coupling constants and reverts to an XXZ Heisenberg model where the given parameter is the coupling constant along the z-direction
`-BCopen`	Either for open boundary conditions or for periodic (toroidal) boundary conditions. Only at most one of them can be true. If none of them are set, the default cylindrical boundary conditions are used.
`-BCperiodic`

See also: Options regarding the DMRG runtime can be found at the DMRGBlockContainer documentation.

Definition at line 77 of file Hamiltonians.hpp.

Public Member Functions
	J1J2XXZModel_SquareLattice ()
	Constructor. More...

PetscErrorCode	SetFromOptions ()
	Set attributes from command line arguments. More...

PetscErrorCode	SaveAsOptions (const std::string &filename)
	Dumps options keys and values to file. More...

PetscInt	NumSites () const
	Returns the number of sites in the square lattice. More...

PetscInt	NumEnvSites () const
	Returns the number of sites in a single cluster/column of the environment block as suggested by Liang and Pang, 1994, for the square lattice. More...

std::vector< Term >	H (const PetscInt &nsites)
	Returns the object used to construct the Hamiltonian using sites counted from the left side of the lattice. More...

void	PrintOut () const
	Prints out some information to stdout. More...

void	SaveOut (FILE *fp) const
	Writes out some JSON information to stdout. More...

PetscInt	Lx () const

PetscInt	Ly () const

PetscInt	To1D (const PetscInt ix, const PetscInt jy) const

PetscErrorCode	To2D (const PetscInt idx, PetscInt &ix, PetscInt &jy) const

std::vector< std::vector< PetscInt > >	NeighborPairs (const PetscInt d=1) const
	Returns all pairs of nearest-neighbors in the full square lattice. More...

Private Member Functions
PetscErrorCode	PrintInfo () const
	Prints some information related to the parameters of the Hamiltonian. More...

std::vector< PetscInt >	GetNearestNeighbors (const PetscInt &ix, const PetscInt &jy, const PetscInt &nsites_in) const
	Given the 2d lattice coordinates, this function retrieves the nearest neighbors' 1D coordinates. More...

std::vector< PetscInt >	GetNextNearestNeighbors (const PetscInt &ix, const PetscInt &jy, const PetscInt &nsites_in) const
	Given the 2d lattice coordinates, this function retrieves the next-nearest neighbors' 1D coordinates. More...

Private Attributes
PetscBool	heisenberg = PETSC_FALSE
	Whether to use the Heisenberg model. More...

PetscBool	set_from_options = PETSC_FALSE
	Set from options. More...

PetscScalar	_Jz1 = 0.0
	Transverse anisotropy for nearest-neighbor interactions. More...

PetscScalar	_Jz2 = 0.0
	Transverse anisotropy for next-nearest-neighbor interactions. More...

PetscScalar	_J1 = 1.0
	Coupling strength for nearest-neighbor interactions. More...

PetscScalar	_J2 = 1.0
	Coupling strength for next-nearest-neighbor interactions. More...

PetscInt	_Lx = 4
	Length along (growing) longitudinal direction. More...

PetscInt	_Ly = 4
	Length along (fixed) transverse direction. More...

PetscBool	verbose = PETSC_FALSE
	Flag that tells whether to print some information. More...

BC_t	_BCx = OpenBC
	Boundary conditions for the longitudinal direction (defaults to cylindrical BC) More...

BC_t	_BCy = PeriodicBC
	Boundary conditions for the transverse direction (defaults to cylindrical BC) More...

std::vector< Term >	H_full
	Contains the Hamiltonian involving the entire lattice. More...

PetscBool	H_full_filled = PETSC_FALSE
	Tells whether H_full has been constructed. More...

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

Public Member Functions