Parameters for calculating acTransmission coefficients
Parameters here are for calculating the ac transport coefficients of quantum transport.
calculation.acTransmission.acFrequencyRange
keyword: calculation.acTransmission.acFrequencyRange
possible values: an 1 x 2 double array
default value: [0,30]
description: The ac transmission is dependent on the ac frequency. This parameter defines a frequency range, and the ac transmission curve over the range will be calculated. The unit is GHz.
an example:
calculation.acTransmission.acFrequencyRange = [10 20]
calculation.acTransmission.numberOfFrequencyPoints
keyword: calculation.acTransmission.numberOfFrequencyPoints
possible values: an integer number
default value: 101
description: number of the frequency points at which the ac transmission coefficients are calculated.
an example:
calculation.acTransmission.numberOfFrequencyPoints = 501
calculation.acTransmission.normalizedAcVoltage
keyword: calculation.acTransmission.normalizedAcVoltage
possible values: an 1 x n double array
default value: [0.1, 1, 10]
description: The ac transmission is also dependent on the ac voltage. This parameter, defined as a dimensionless value of eV/Eph with V the ac voltage and the Eph the photon energy of the corresponding ac frequency, is a normailized ac voltage at which the ac transmission will be calculated.
an example:
calculation.acTransmission.normalizedAcVoltage = [0.1:0.1:1]
calculation.acTransmission.leadPairs
keyword: calculation.acTransmission.leadPairs
possible values: cell array of 1 x 2 integer array
default value: all pairs of leads
description: For each pair of leads in the cell, the transmission from the first lead of the pair to the second lead is to be calculated.
an example:
calculation.acTransmission.leadPairs = {[1,2], [2,1]}
calculation.acTransmission.kSpaceGridNumber
keyword: calculation.acTransmission.kSpaceGridNumber
possible values: 3 x 1 integer array
default value: the value of calculation.k_spacegrids.number which was used in the Hamiltonian calculation, or [1 1 1] if an user provided Hamiltonian is used.
description: number of small k-space grids in each direction which, together with kSpaceGridShift, are used to produce the parameter kSpacePoints.
an example:
calculation.acTransmission.kSpaceGridNumber = [10 10 10]'
calculation.acTransmission.kSpaceGridShift
keyword: calculation.acTransmission.kSpaceGridShift
possible values: 3 x 1 or 1 x 3 array, [s_1, s_2, s_3], with each s_i a double number between 0 and 1.
default value: if the acTransmission.kSpaceGridNumber is given, or if an user provided Hamiltonian is used, the default value is [0 0 0], otherwise the default value is the value of calculation.k_spacegrids.shift which was used in the Hamiltonian calculation.
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 lengths along their grid vector directions, respectively.
an example:
calculation.acTransmission.kSpaceGridShift = [1/2 1/2 1/2]'
calculation.acTransmission.energyPoints
keyword: calculation.acTransmission.energyPoints
possible values: double array
default value: chemical potentials of all the leads.
description: the energy points at which the transmission will be calculated. Note that the energy values are measured from chemical potential of a lead having zero applied voltage.
an example:
calculation.acTransmission.energyPoints = 0
calculation.acTransmission.etaSigma
keyword: calculation.acTransmission.etaSigma
possible values: a small double number
default value: 1e-6 Hartree
description: the small eta used in the calculation of self-energy when the ‘GreenFunction’ method is chosen.
an example:
calculation.acTransmission.etaSigma = 1e-4
calculation.acTransmission.etaGF
keyword: calculation.acTransmission.etaGF
possible values: a small double number
default value: 0
description: the small eta used in the calculation of Green’s function when the ‘GreenFunction’ method is chosen.
an example:
calculation.acTransmission.etaGF = 1e-4
calculation.acTransmission.eta
keyword: calculation.acTransmission.eta
possible values: a small double number
default value: no default value
description: the small eta used in the calculation of self-energy and/or Green’s function when the ‘GreenFunction’ method is chosen. This parameter is only used when the parameter cTransmission.etaSigma and/or acTransmission.etaGF is not given.
an example:
calculation.acTransmission.eta = 1e-4
calculation.acTransmission.plot
keyword: calculation.acTransmission.plot
possible values: true or false
default value: false
description: If true, a plot will be given after the calculation.
an example:
calculation.acTransmission.plot = true