Add symmetry analysis and explore symmetries of model

code/testing_ground.py

@@ -2,6 +2,7 @@
 import kwant
 import numpy as np
 import matplotlib.pyplot as plt
+import kwant.qsymm as kwant_qsymm
 
 from modules.diamond_chain import diamond_chain_system
 from modules.analysis_funcs import ldos_from_kpm, ldos_modes_from_leads
@@ -9,25 +10,23 @@ from modules.analysis_funcs import ldos_from_kpm, ldos_modes_from_leads
 # -
 
 system_params = dict(
-    mu_a_pos = 0.4,
-    mu_a_neg = -0.2,
-    mu_b_pos = -0.3,
-    mu_b_neg = 0.3,
-    mu_c_pos = 0.1,
+    mu_a_pos = 0.3,
+    mu_a_neg = -0.1,
+    mu_b_pos = 0.,
+    mu_b_neg = -0.,
+    mu_c_pos = 0.3,
     mu_c_neg = -0.1,
     j2 = 1,
     j3 = 1,
     phi = np.pi/2,
-    phi_d = 0.3
+    phi_d = 0.
 )
 
 inf_chain = diamond_chain_system(5,system_params, semi_infinite = True)
 fin_chain = diamond_chain_system(5,system_params, semi_infinite = False)
 # o = kwant.plot(fin_chain)
 
-# +
-# ldos_modes_from_leads(fin_chain.finalized(), system_params) #doesn't work for flat bands
-# -
+# ## LDOS
 
 o = ldos_from_kpm(fin_chain.finalized(), system_params, vmax = 10, energy = 0 )
 
@@ -35,7 +34,11 @@ o = ldos_from_kpm(fin_chain.finalized(), system_params, vmax = 1, energy = 2*sys
 
 o = ldos_from_kpm(fin_chain.finalized(), system_params, vmax = 10, energy = 2*np.sqrt(2)*system_params['j2'] )
 
-kwant.plotter.bands(inf_chain.finalized(), momenta = np.linspace(-np.pi,np.pi,1000))
+# ## Spectrum
+
+p = kwant.plotter.bands(inf_chain.finalized(), momenta = np.linspace(-np.pi,np.pi,1000))
+
+# ## Eigenvalues
 
 ham = fin_chain.finalized().hamiltonian_submatrix()
 
@@ -45,6 +48,12 @@ ev
 
 plt.plot(ev, marker='o',lw=0)
 
-np.exp(1j*np.pi/2).imag
+# ## Symmetries
+
+# +
+symmetries = kwant_qsymm.find_builder_symmetries(inf_chain, params=system_params, sparse=True,)
+
+symmetries
+# -