From 2103cd5bd5327a19a1a0636c1af50c13cd925fc1 Mon Sep 17 00:00:00 2001
From: Anton Akhmerov <anton.akhmerov@gmail.com>
Date: Sat, 27 Apr 2013 00:27:43 -0400
Subject: [PATCH] add ModesLead, a modes analog of SelfEnergy lead
---
kwant/builder.py | 35 +++++++++++++++++++++++++++++++----
kwant/system.py | 3 ++-
2 files changed, 33 insertions(+), 5 deletions(-)
diff --git a/kwant/builder.py b/kwant/builder.py
index 82462dc9..53b3bd62 100644
--- a/kwant/builder.py
+++ b/kwant/builder.py
@@ -9,7 +9,7 @@
from __future__ import division
__all__ = ['Builder', 'Site', 'SiteFamily', 'SimpleSiteFamily', 'Symmetry',
- 'HoppingKind', 'Lead', 'BuilderLead', 'SelfEnergy']
+ 'HoppingKind', 'Lead', 'BuilderLead', 'SelfEnergy', 'ModesLead']
import abc
import sys
@@ -18,7 +18,7 @@ import operator
from itertools import izip, islice, chain
import tinyarray as ta
import numpy as np
-from . import system, graph
+from . import system, graph, physics
################ Sites and site families
@@ -450,7 +450,7 @@ class SelfEnergy(Lead):
interface : sequence of `Site` instances
"""
def __init__(self, self_energy_func, interface):
- self.self_energy_func = self_energy_func
+ self._self_energy_func = self_energy_func
self.interface = tuple(interface)
def finalized(self):
@@ -458,7 +458,34 @@ class SelfEnergy(Lead):
return self
def self_energy(self, energy, args=()):
- return self.self_energy_func(energy, args)
+ return self._self_energy_func(energy, args)
+
+
+class ModesLead(Lead):
+ """A general lead defined by its modes wave functions.
+
+ Parameters
+ ----------
+ modes_func : function
+ Function which returns the modes of the lead in the format required by
+ a solver given the energy and optionally a list of extra arguments.
+ interface : sequence of `Site` instances
+ """
+ def __init__(self, modes_func, interface):
+ self._modes_func = modes_func
+ self.interface = tuple(interface)
+
+ def finalized(self):
+ """Trivial finalization: the object is returned itself."""
+ return self
+
+ def modes(self, energy, args=()):
+ return self._modes_func(energy, args)
+
+ def self_energy(self, energy, args=()):
+ modes = self.modes(energy, args)
+ return physics.selfenergy(modes=modes)
+
################ Builder class
diff --git a/kwant/system.py b/kwant/system.py
index 09a36296..134bdcf2 100644
--- a/kwant/system.py
+++ b/kwant/system.py
@@ -80,7 +80,8 @@ class FiniteSystem(System):
For lead ``n``, the method leads[n].self_energy must return a square matrix
whose size is ``sum(self.num_orbitals(neighbor) for neighbor in
- self.lead_interfaces[n])``.
+ self.lead_interfaces[n])`` the output format for ``leads[n].modes is more
+ complicated, and it should match the output of `kwant.physics.modes`.
Often, the elements of `leads` will be instances of `InfiniteSystem`. If
this is the case for lead ``n``, the sites ``lead_interfaces[n]`` match
--
GitLab