.. graphene_flake documentation master file, created by
   sphinx-quickstart on Thu Jun 25 12:35:53 2015.
   You can adapt this file completely to your liking, but it should at least
   contain the root `toctree` directive.

Strained Graphene
=================


**graphene_flake** is a package providing a Python implementation of graphene flakes. It can be used to build up and solve tight-binding model, analyze the pseudo Landau levels (pLLs) creation, their wavefunction support, and vortex-induced defect states.

.. toctree::
    :hidden:

    about
    code
    examples

Installation
------------

**graphene_flake** is available at https://github.com/cpoli/graphene_flake

To use **graphene_flake**,  you need to install the programming language python and three additional packages:

* python 3.x
* numpy
* scipy
* matplotlib



Quick example
-------------

This example shows how to define a hexagonal strained graphene flake with zizzag-terminated edges, `examples <examples.html>`_.

.. image:: figs/lattice_N144_0,0.png
    :width:  45%
    :align: center

.. code-block:: python

    from graphene_flake import * # import graphene_flake model class

    flake = tri_to_hexa_zz(sites_base=10, sites_cut=0, t_1=1., t_2=1., t_3=1.)
    flake.plt_lattice(s=150, save=True)
    flake.get_eig_lin_strain(strain=0., eig_vec=True, vortex=False)
    flake.plt_spec(no_bins=41, ener_lim=[-2., 2.], plt_pola=True, save=True)
    flake.get_states_selec(e_min=-0.005, e_max=0.005)
    flake.plt_states_selec(coef=50000, plt_bonds=True, plt_axis=False, save=True)
    flake.plt_show()

.. image:: figs/spec_N144_0,0.png
    :width: 55%

.. image:: figs/states_N144_0,0_-0,005_0,005.png
    :width: 40%


.. Note::

    :math:`N` sites at the base of the triangle flake lead to :math:`N` zero-modes. The zero-modes are uniquely localized on the A sublattice (represented in blue). The existence of the zero-modes are due to :math:`N` extra A sites.