GOLLUM is a program that computes the charge, spin and thermal transport properties of multi-terminal nano-scale junctions.

The program can compute transport properties of either user-defined systems described by a tight-binding Hamiltonian, or more material-specific properties of systems composed of real atoms described by DFT Hamiltonians.

GOLLUM: a next generation quantum transport simulation tool

GOLLUM delivers the following functionalities:

1. Simulates multi-terminal devices

2. Reads either Tight-Binding or DFT hamiltonians

3. Computes the full scattering matrix

4. Computes charge transport

- Number of open scattering channels

- Electronic transmission and reflection coefficents

- Shot-noise

5. Computes heat transport

- Thermal conductance due to both electrons and phonons

- Thermopower (Seebeck coefficent)

- Peltier coefficent

- Thermoelectric Figure of merite ZT

6. Computes spin transport

- Collinear spins systems

- Non-collinear spins systems

- Systems with strong spin-orbit interaction

7. Computes phonon transport

- Number of open phononic scattering channels

- Phononic transmission and reflection coefficents

8. Computes zero-voltage as well as I-V curves

9. Handles vdW and LDA+U functionals

10. Allows spectral adjustment for strongly correlated systems

11. Computes band-structure, density of state and number of open chanells of leads

12. Covers large samples enabling to analize ballistic to diffusive regimes

13. In addition to interface to Siesta code which uses a localized basis set, Gollum can read output Wannier Hamiltonians from the Wannier90 code. So Gollum interfaces now with plane wave codes such as Castep, VASP, ABINIT and Quantum-Espresso.

Version 3.0 will come with

  •     **  Kondo & Coulomb blockade physics
  •     **  Magnetic field and integer quantum Hall effect
  •     **  Info about Local charge, spin, current and spin-current densities inside the scattering region
  •     **  Scripts to handle multiscale simulations


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