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Pablo Piskunow
kwant
Commits
7ed157c5
Commit
7ed157c5
authored
Feb 03, 2014
by
Christoph Groth
Browse files
doc: move "see also" boxes with links to full examples to the top of each section
parent
31f76745
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6
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doc/source/tutorial/tutorial1.rst
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7ed157c5
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@@ -58,6 +58,10 @@ simplicity, we choose to work in such units that :math:`t = a = 1`.
Transport through a quantum wire
................................
.. seealso::
The complete source code of this example can be found in
:download:`tutorial/quantum_wire.py <../../../tutorial/quantum_wire.py>`
In order to use Kwant, we need to import it:
.. literalinclude:: quantum_wire.py
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@@ -232,10 +236,6 @@ value of the conductance is determined by the number of occupied
subbands that increases with energy.
.. seealso::
The full source code can be found in
:download:`tutorial/quantum_wire.py <../../../tutorial/quantum_wire.py>`
.. specialnote:: Technical details
- In the example above, when building the system, only one direction
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@@ -326,6 +326,10 @@ subbands that increases with energy.
Building the same system with less code
.......................................
.. seealso::
The complete source code of this example can be found in
:download:`tutorial/quantum_wire_revisited.py <../../../tutorial/quantum_wire_revisited.py>`
Kwant allows for more than one way to build a system. The reason is that
`~kwant.builder.Builder` is essentially just a container that can be filled in
different ways. Here we present a more compact rewrite of the previous example
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@@ -432,10 +436,6 @@ hand, you also have access to the other functions, ``make_system`` and
The result of the example should be identical to the previous one.
.. seealso::
The full source code can be found in
:download:`tutorial/quantum_wire_revisited.py <../../../tutorial/quantum_wire_revisited.py>`
.. specialnote:: Technical details
- We have seen different ways to add lattice points to a
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doc/source/tutorial/tutorial2.rst
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@@ -9,6 +9,10 @@ very simple examples of the previous section.
Matrix structure of on-site and hopping elements
................................................
.. seealso::
The complete source code of this example can be found in
:download:`tutorial/spin_orbit.py <../../../tutorial/spin_orbit.py>`
We begin by extending the simple 2DEG-Hamiltonian by a Rashba spin-orbit
coupling and a Zeeman splitting due to an external magnetic field:
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@@ -90,10 +94,6 @@ the following, clearly non-monotonic conductance steps:
.. image:: ../images/spin_orbit_result.*
.. seealso::
The full source code can be found in
:download:`tutorial/spin_orbit.py <../../../tutorial/spin_orbit.py>`
.. specialnote:: Technical details
- The Tinyarray package, one of the dependencies of Kwant, implements
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@@ -127,6 +127,10 @@ the following, clearly non-monotonic conductance steps:
Spatially dependent values through functions
............................................
.. seealso::
The complete source code of this example can be found in
:download:`tutorial/quantum_well.py <../../../tutorial/quantum_well.py>`
Up to now, all examples had position-independent matrix-elements
(and thus translational invariance along the wire, which
was the origin of the conductance steps). Now, we consider the
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@@ -190,10 +194,6 @@ of the potential well by passing the potential value. We obtain the result:
Starting from no potential (well depth = 0), we observe the typical
oscillatory transmission behavior through resonances in the quantum well.
.. seealso::
The full source code can be found in
:download:`tutorial/quantum_well.py <../../../tutorial/quantum_well.py>`
.. warning::
If functions are used to set values inside a lead, then they must satisfy
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@@ -214,6 +214,10 @@ oscillatory transmission behavior through resonances in the quantum well.
Nontrivial shapes
.................
.. seealso::
The complete source code of this example can be found in
:download:`tutorial/ab_ring.py <../../../tutorial/ab_ring.py>`
Up to now, we only dealt with simple wire geometries. Now we turn to the case
of a more complex geometry, namely transport through a quantum ring
that is pierced by a magnetic flux :math:`\Phi`:
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@@ -313,10 +317,6 @@ Finally you should get the following result:
where one can observe the conductance oscillations with the
period of one flux quantum.
.. seealso::
The full source code can be found in
:download:`tutorial/ab_ring.py <../../../tutorial/ab_ring.py>`
.. specialnote:: Technical details
- Leads have to have proper periodicity. Furthermore, the Kwant
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doc/source/tutorial/tutorial3.rst
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@@ -4,6 +4,10 @@ Beyond transport: Band structure and closed systems
Band structure calculations
...........................
.. seealso::
The complete source code of this example can be found in
:download:`tutorial/band_structure.py <../../../tutorial/band_structure.py>`
When doing transport simulations, one also often needs to know the band
structure of the leads, i.e. the energies of the propagating plane waves in the
leads as a function of momentum. This band structure contains information about
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@@ -50,13 +54,13 @@ where we observe the cosine-like dispersion of the square lattice. Close
to ``k=0`` this agrees well with the quadratic dispersion this tight-binding
Hamiltonian is approximating.
.. seealso::
The full source code can be found in
:download:`tutorial/band_structure.py <../../../tutorial/band_structure.py>`
Closed systems
..............
.. seealso::
The complete source code of this example can be found in
:download:`tutorial/closed_system.py <../../../tutorial/closed_system.py>`
Although Kwant is (currently) mainly aimed towards transport problems, it
can also easily be used to compute properties of closed systems -- after
all, a closed system is nothing more than a scattering region without leads!
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@@ -114,10 +118,6 @@ The last two arguments to `~kwant.plotter.map` are optional. The first prevents
a colorbar from appearing. The second, ``oversampling=1``, makes the image look
better for the special case of a square lattice.
.. seealso::
The full source code can be found in
:download:`tutorial/closed_system.py <../../../tutorial/closed_system.py>`
.. specialnote:: Technical details
- `~kwant.system.System.hamiltonian_submatrix` can also return a sparse
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doc/source/tutorial/tutorial4.rst
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@@ -3,6 +3,10 @@
Beyond square lattices: graphene
--------------------------------
.. seealso::
The complete source code of this example can be found in
:download:`tutorial/graphene.py <../../../tutorial/graphene.py>`
In the following example, we are going to calculate the
conductance through a graphene quantum dot with a p-n junction
and two non-collinear leads. In the process, we will touch
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@@ -164,10 +168,6 @@ Finally the transmission through the system is computed,
showing the typical resonance-like transmission probability through
an open quantum dot
.. seealso::
The full source code can be found in
:download:`tutorial/graphene.py <../../../tutorial/graphene.py>`
.. specialnote:: Technical details
- In a lattice with more than one basis atom, you can always act either
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doc/source/tutorial/tutorial5.rst
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@@ -24,6 +24,10 @@ choose real), and :math:`\mathcal{T}H\mathcal{T}^{-1}=H_0^*=H_0`.
"Orbital description": using matrices
.....................................
.. seealso::
The complete source code of this example can be found in
:download:`tutorial/superconductor_band_structure.py <../../../tutorial/superconductor_band_structure.py>`
We begin by computing the band structure of a superconducting wire.
The most natural way to implement the BdG Hamiltonian is by using a
2x2 matrix structure for all Hamiltonian matrix elements:
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@@ -43,14 +47,14 @@ Computing the band structure then yields the result
We clearly observe the superconducting gap in the spectrum. That was easy,
wasn't it?
.. seealso::
The full source code can be found in
:download:`tutorial/superconductor_band_structure.py <../../../tutorial/superconductor_band_structure.py>`
"Lattice description": using different lattices
...............................................
.. seealso::
The complete source code of this example can be found in
:download:`tutorial/superconductor_transport.py <../../../tutorial/superconductor_transport.py>`
While it seems most natural to implement the BdG Hamiltonian
using a 2x2 matrix structure for the matrix elements of the Hamiltonian,
we run into a problem when we want to compute electronic transport in
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@@ -153,10 +157,6 @@ We a see a conductance that is proportional to the square of the tunneling
probability within the gap, and proportional to the tunneling probability
above the gap. At the gap edge, we observe a resonant Andreev reflection.
.. seealso::
The full source code can be found in
:download:`tutorial/superconductor_transport.py <../../../tutorial/superconductor_transport.py>`
.. specialnote:: Technical details
- If you are only interested in particle (thermal) currents you do not need
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doc/source/tutorial/tutorial6.rst
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@@ -10,6 +10,10 @@ these options can be used to achieve various very different objectives.
2D example: graphene quantum dot
................................
.. seealso::
The complete source code of this example can be found in
:download:`tutorial/plot_graphene.py <../../../tutorial/plot_graphene.py>`
We begin by first considering a circular graphene quantum dot (similar to what
has been used in parts of the tutorial :ref:`tutorial-graphene`.) In contrast
to previous examples, we will also use hoppings beyond next-nearest neighbors:
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@@ -135,10 +139,6 @@ With this, we arrive at
which shows the edge state nature of the wave function most clearly.
.. seealso::
The full source code can be found in
:download:`tutorial/plot_graphene.py <../../../tutorial/plot_graphene.py>`
.. rubric:: Footnotes
.. [#] A dangling site is defined as having only one hopping connecting it to
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@@ -148,6 +148,10 @@ which shows the edge state nature of the wave function most clearly.
3D example: zincblende structure
................................
.. seealso::
The complete source code of this example can be found in
:download:`tutorial/plot_zincblende.py <../../../tutorial/plot_zincblende.py>`
Zincblende is a very common crystal structure of semiconductors. It is a
face-centered cubic crystal with two inequivalent atoms in the unit cell
(i.e. two different types of atoms, unlike diamond which has the same crystal
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@@ -222,7 +226,3 @@ crystal lattices out there!
3d module)
- Plotting hoppings in 3D is inherently much slower than plotting sites.
Hence, this is not done by default.
.. seealso::
The full source code can be found in :download:`tutorial/plot_zincblende.py
<../../../tutorial/plot_zincblende.py>`
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