From cea2b1b0118f886e069db0cbe605dc82042ad3e0 Mon Sep 17 00:00:00 2001 From: Joseph Weston <joseph@weston.cloud> Date: Fri, 15 Feb 2019 15:31:27 +0100 Subject: [PATCH] add missing whatsnew entries --- doc/source/pre/whatsnew/1.4.rst | 59 +++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) diff --git a/doc/source/pre/whatsnew/1.4.rst b/doc/source/pre/whatsnew/1.4.rst index 33ec8a92..22edb456 100644 --- a/doc/source/pre/whatsnew/1.4.rst +++ b/doc/source/pre/whatsnew/1.4.rst @@ -191,6 +191,46 @@ a dictionary using ``params``:: The ability to provide ``args`` will be removed in a future Kwant version. +Conductivity calculations using KPM +----------------------------------- +Kwant now has the ability to calculate conductivities using a combination of +the Kernel Polynomial Method and the Kubo-Bastin relation in the `kwant.kpm` +module. The following example calculates :math:`σ_{xy}` for various chemical +potentials at finite temperature:: + + syst = make_system().finalized() + sigma_xy = kwant.kpm.conductivity(syst, alpha='x', beta='y') + conductivities = [sigma_xy(mu=mu, temp=0.1) for mu in np.linspace(0, 4)] + +`kwant.physics.Bands` can optionally return eigenvectors and velocities +----------------------------------------------------------------------- +`kwant.physics.Bands` now takes extra parameters that allow it to +return the mode eigenvectors, and also the derivatives of the dispersion +relation (up to second order) using the Hellman-Feynman relation:: + + syst = make_system().finalized() + + bands = kwant.physics.Bands(syst) + (energies, velocities, vectors) = bands(k=0, derivative_order=1, return_eigenvectors=True) + +Installation on Microsoft Windows is available via Conda +-------------------------------------------------------- +Kwant is now packaged for the Conda package manager on Windows, and using +Conda is the preferred method for installing Kwant on that platform. +Please refer to the +`installation section <https://kwant-project.org/install#microsoft-windows>`_ +of the Kwant website for details. +Currently the MUMPS solver is not available for the Windows version of the +Conda package; we hope to include MUMPS support in a later patch release. + +Finalized Builders keep track of which sites were added when attaching leads +---------------------------------------------------------------------------- +When attaching leads to an irregularly shaped scattering region, Kwant adds +sites in order to make the interface with the leads "smooth". Previously, +the information of which sites were added was not inspectable after finalization. +Now the sites that were added from each lead are available in the ``lead_paddings`` +attribute. See the documentation for `~kwant.builder.FiniteSystem` for details. + Interpolated density plots -------------------------- A new function `~kwant.plotter.density` has been added that can be used to @@ -207,6 +247,18 @@ that this option is not available in `~kwant.plotter.current`. In order to use it, one has to call ``streamplot`` directly as shown in the docstring of ``current``. +The minimum required versions for some dependencies have increased +------------------------------------------------------------------ +Kwant now requires at least the following versions: + ++ Python 3.5 ++ numpy 0.11.0 ++ scipy 0.17.0 ++ matplotlib 1.5.1 + +These versions (or newer) are available in the latest stable releases +of Ubuntu and Debian GNU/Linux. + kwant.continuum.discretize can be used with rectangular lattices ---------------------------------------------------------------- Previously the discretizer could only be used with lattices with the same @@ -231,3 +283,10 @@ data would appear near the bottom of the color scale, and all of the features would be washed out by the presence of the peak. Now `~kwant.plotter.map` employs a heuristic for setting the colorscale when there are outliers, and will emit a warning when this is detected. + +Sites from different families are plotted in different colors by default +------------------------------------------------------------------------ +Previously `kwant.plot` would plot all sites in black. Now sites from +different families are plotted in different colors, which improves the +default plotting style. You can still customize the site coloring using +the ``site_color`` parameter, as before. -- GitLab