Parameters for calculating scatteringStates¶

Parameters here are for calculating the scattering states of quantum transport.

calculation.scatteringStates.kSpaceGridNumber¶

key word	:	calculation.scatteringStates.kSpaceGridNumber
possible values	:	3\(\times\)1 integer array
default value	:	no default value
description	:	the small k-space grid number in each direction which,
		together with kSpaceGridShift, are used to produce the
		parameter kSpacePoints.
an example	:	calculation.scatteringStates.kSpaceGridNumber = [10 10 10]

key word	:	calculation.scatteringStates.kSpaceGridShift
possible values	:	3\(\times\)1 or 1\(\times\)3 array, [s\(_1\), s\(_2\), s\(_3\)], with each s\(_i\) a
		double number between 0 and 1.
default value	:	[0 0 0]
description	:	k-space grid point shift. While all s\(_i\) are set to be 0,
		the Gamma point is always among the k-space grid points
		being generated; otherwise, the k-space grid points will
		be shifted s\(_1\), s\(_2\), and s\(_3\) grid length along their
		grid vector directions, respectively.
an example	:	calculation.scatteringStates.kSpaceGridShift = [1/2 1/2 1/2]

key word	:	calculation.scatteringStates.kSpacePoints
possible values	:	3\(\times\)n double array
default value	:	produced by parameter kSpaceGridNumber if it is given,
		otherwise, [0 0 0] (i.e. gamma point only)
description	:	the fractional coordinates of n k-space points at which
		the scattering states will be calculated.
an example	:	calculation.scatteringStates.kSpacePoints = [0 0 0]

key word	:	calculation.scatteringStates.energyPoints
possible values	:	double array
default value	:	chemical potentials of all the leads.
description	:	the energy points at which the scattering states will be
		calculated.
		Note that the energy values are measured from chemical
		potential of a lead that has zero applied voltage.
an example	:	calculation.scatteringStates.energyPoints = 0

key word	:	calculation.scatteringStates.leadIndexOfIncomingStates
possible values	:	integer array
default value	:	1:totalNumberOfLeads (i.e. all leads)
description	:	lead index. Scattering states corresponding to all
		incoming state of the given leads will be calculated.
an example	:	calculation.scatteringStates.leadIndexOfIncomingStates = 1

key word	:	calculation.scatteringStates.whatNormalized
possible values	:	Current and Charge
default value	:	Current
description	:	If Current, the incoming and outgoing Bloch waves in
		all leads will be normalized to unit current; if
		Charge, to unit charge.
an example	:	calculation.scatteringStates.whatNormalized = Current

key word	:	calculation.scatteringStates.epsilon
possible values	:	a small double number
default value	:	1e-9
description	:	used as a criteria for identification of a Bloch wave.
		If \|imag(k)\| < epsilon, where k is the wave vector of a
		wave function in unit of [2\(\pi\)/unit_cell_length], the
		wave function will be identified as a Bloch wave;
		otherwise, a decaying wave.
an example	:	calculation.scatteringStates.epsilon = 1e-6

key word	:	calculation.scatteringStates.realSpace
possible values	:	true or false
default value	:	false
description	:	If true, real space wavefunctions of the scattering
		states will be calculated in a region defined by the
		parameters regionPosition and regionVectors.
an example	:	calculation.scatteringStates.realSpace = true

key word	:	calculation.scatteringStates.regionPosition
possible values	:	a 3\(\times\)1 double array
default value	:	[0;0;0]
description	:	When realSpace is true, this parameter and
		regionVectors define a real space region in which
		wavefunctions of the scattering states will be
		calculated.
an example	:	calculation.scatteringStates.regionPosition = [1,1,1]

key word	:	calculation.scatteringStates.regionVectors
possible values	:	a 3\(\times\)3 double array
default value	:	the value of system.centralCellVectors which was used in
		the Hamiltonian calculation
description	:	When realSpace is true, this parameter and
		regionPosition define a real space region in which
		wavefunctions of the scattering states will be
		calculated.
an example	:	calculation.scatteringStates.regionVectors = eye(3)*2

key word	:	calculation.scatteringStates.regionGridNumber
possible values	:	3\(\times\)1 integer vector
default value	:	the value of calculation.realspacegrids.number which was
		used in the Hamiltonian calculation
description	:	the small grid number in each direction of regionVectors.
		It is used to define a set of real space point in
		the region defined by regionPosition and regionVectors,
		at which wavefunctions of the scattering states will be
		calculated.
an example	:	calculation.scatteringStates.regionGridNumber = [4 4 4]

key word	:	calculation.scatteringStates.plot
possible values	:	true or false
default value	:	false
description	:	If true, a plot will be given after the calculation.
an example	:	calculation.scatteringStates.plot = true