update

academic_codes/2019.11.01_conductance_calculation_using_Green_functions/conductance_calculation_using_Green_functions.py

@@ -91,9 +91,9 @@ def conductance(fermi_energy, h00, h01, nx=300):  # 计算电导
         else:
             green_nn_n = np.linalg.inv(fermi_energy*np.identity(dim)-h00-np.dot(np.dot(h01.transpose().conj(), green_nn_n), h01)-right_self_energy)
             green_0n_n = np.dot(np.dot(green_0n_n, h01), green_nn_n)
-    right_self_energy = (right_self_energy - right_self_energy.transpose().conj())*(0+1j)
-    left_self_energy = (left_self_energy - left_self_energy.transpose().conj())*(0+1j)
-    transmission = np.trace(np.dot(np.dot(np.dot(left_self_energy, green_0n_n), right_self_energy), green_0n_n.transpose().conj()))
+    gamma_right = (right_self_energy - right_self_energy.transpose().conj())*(0+1j)
+    gamma_left = (left_self_energy - left_self_energy.transpose().conj())*(0+1j)
+    transmission = np.trace(np.dot(np.dot(np.dot(gamma_left, green_0n_n), gamma_right), green_0n_n.transpose().conj()))
     return transmission  # 返回电导值
 
 

academic_codes/2021.02.08_quantum_transport_in_multi_lead_systems/quantum_transport_in_multi_lead_systems.py

@@ -80,13 +80,14 @@ def main():
         H_from_lead_4_to_center = np.zeros((width, width*length), dtype=complex)
         H_from_lead_5_to_center = np.zeros((width, width*length), dtype=complex)
         H_from_lead_6_to_center = np.zeros((width, width*length), dtype=complex)
+        move = 0 # the step of leads 2,3,6,5 moving to center
         for i0 in range(width):
             H_from_lead_1_to_center[i0, i0] = 1
-            H_from_lead_2_to_center[i0, width*i0+(width-1)] = 1
-            H_from_lead_3_to_center[i0, width*(length-1-i0)+(width-1)] = 1
+            H_from_lead_2_to_center[i0, width*(move+i0)+(width-1)] = 1
+            H_from_lead_3_to_center[i0, width*(length-move-1-i0)+(width-1)] = 1
             H_from_lead_4_to_center[i0, width*(length-1)+i0] = 1
-            H_from_lead_5_to_center[i0, width*(length-1-i0)+0] = 1
-            H_from_lead_6_to_center[i0, width*i0+0] = 1
+            H_from_lead_5_to_center[i0, width*(length-move-1-i0)+0] = 1
+            H_from_lead_6_to_center[i0, width*(move+i0)+0] = 1
 
         # 自能    
         self_energy_1 = np.dot(np.dot(H_from_lead_1_to_center.transpose().conj(), lead_1), H_from_lead_1_to_center)
@@ -100,19 +101,19 @@ def main():
         green = np.linalg.inv(fermi_energy*np.eye(width*length)-H_scattering_region-self_energy_1-self_energy_2-self_energy_3-self_energy_4-self_energy_5-self_energy_6)
 
         # Gamma矩阵
-        self_energy_1 = 1j*(self_energy_1-self_energy_1.transpose().conj())
-        self_energy_2 = 1j*(self_energy_2-self_energy_2.transpose().conj())
-        self_energy_3 = 1j*(self_energy_3-self_energy_3.transpose().conj())
-        self_energy_4 = 1j*(self_energy_4-self_energy_4.transpose().conj())
-        self_energy_5 = 1j*(self_energy_5-self_energy_5.transpose().conj())
-        self_energy_6 = 1j*(self_energy_6-self_energy_6.transpose().conj())
+        gamma_1 = 1j*(self_energy_1-self_energy_1.transpose().conj())
+        gamma_2 = 1j*(self_energy_2-self_energy_2.transpose().conj())
+        gamma_3 = 1j*(self_energy_3-self_energy_3.transpose().conj())
+        gamma_4 = 1j*(self_energy_4-self_energy_4.transpose().conj())
+        gamma_5 = 1j*(self_energy_5-self_energy_5.transpose().conj())
+        gamma_6 = 1j*(self_energy_6-self_energy_6.transpose().conj())
 
         # Transmission
-        transmission_12 = np.trace(np.dot(np.dot(np.dot(self_energy_1, green), self_energy_2), green.transpose().conj()))
-        transmission_13 = np.trace(np.dot(np.dot(np.dot(self_energy_1, green), self_energy_3), green.transpose().conj()))
-        transmission_14 = np.trace(np.dot(np.dot(np.dot(self_energy_1, green), self_energy_4), green.transpose().conj()))
-        transmission_15 = np.trace(np.dot(np.dot(np.dot(self_energy_1, green), self_energy_5), green.transpose().conj()))
-        transmission_16 = np.trace(np.dot(np.dot(np.dot(self_energy_1, green), self_energy_6), green.transpose().conj()))
+        transmission_12 = np.trace(np.dot(np.dot(np.dot(gamma_1, green), gamma_2), green.transpose().conj()))
+        transmission_13 = np.trace(np.dot(np.dot(np.dot(gamma_1, green), gamma_3), green.transpose().conj()))
+        transmission_14 = np.trace(np.dot(np.dot(np.dot(gamma_1, green), gamma_4), green.transpose().conj()))
+        transmission_15 = np.trace(np.dot(np.dot(np.dot(gamma_1, green), gamma_5), green.transpose().conj()))
+        transmission_16 = np.trace(np.dot(np.dot(np.dot(gamma_1, green), gamma_6), green.transpose().conj()))
 
         transmission_12_array.append(np.real(transmission_12))
         transmission_13_array.append(np.real(transmission_13))
@@ -176,4 +177,4 @@ def surface_green_function_lead(fermi_energy, h00, h01, dim):  # 电极的表面
 
 
 if __name__ == '__main__':
-    main()
+    main()

academic_codes/2021.02.08_quantum_transport_in_multi_lead_systems/quantum_transport_in_multi_lead_systems_with_guan.py

@@ -67,13 +67,14 @@ def main():
         h_lead4_to_center = np.zeros((width, width*length), dtype=complex)
         h_lead5_to_center = np.zeros((width, width*length), dtype=complex)
         h_lead6_to_center = np.zeros((width, width*length), dtype=complex)
+        move = 0 # the step of leads 2,3,6,5 moving to center
         for i0 in range(width):
             h_lead1_to_center[i0, i0] = 1
-            h_lead2_to_center[i0, width*i0+(width-1)] = 1
-            h_lead3_to_center[i0, width*(length-1-i0)+(width-1)] = 1
+            h_lead2_to_center[i0, width*(move+i0)+(width-1)] = 1
+            h_lead3_to_center[i0, width*(length-move-1-i0)+(width-1)] = 1
             h_lead4_to_center[i0, width*(length-1)+i0] = 1
-            h_lead5_to_center[i0, width*(length-1-i0)+0] = 1
-            h_lead6_to_center[i0, width*i0+0] = 1
+            h_lead5_to_center[i0, width*(length-move-1-i0)+0] = 1
+            h_lead6_to_center[i0, width*(move+i0)+0] = 1
         # 自能    
         self_energy1, gamma1 = guan.self_energy_of_lead_with_h_lead_to_center(fermi_energy, lead_h00, lead_h01, h_lead1_to_center)
         self_energy2, gamma2 = guan.self_energy_of_lead_with_h_lead_to_center(fermi_energy, lead_h00, lead_h01, h_lead2_to_center)

academic_codes/2021.02.08_quantum_transport_in_multi_lead_systems/quantum_transport_in_multi_lead_systems_with_kwant.py

@@ -20,18 +20,21 @@ def make_system():
     #               lead2         lead3
     #   lead1(L)                          lead4(R)  
     #               lead6         lead5
+
+    move = 0 # the step of leads 2,3,6,5 moving to center
+
     lead1 = kwant.Builder(kwant.TranslationalSymmetry((-a, 0)))
     lead1[(lat(0, j) for j in range(W))] = 0
     lead1[lat.neighbors()] = -t
     syst.attach_lead(lead1) 
 
     lead2 = kwant.Builder(kwant.TranslationalSymmetry((0, -a)))
-    lead2[(lat(j, 0) for j in range(W))] = 0
+    lead2[(lat(move+j, 0) for j in range(W))] = 0
     lead2[lat.neighbors()] = -t  
     syst.attach_lead(lead2) 
 
     lead3 = kwant.Builder(kwant.TranslationalSymmetry((0, -a)))
-    lead3[(lat(j+(L-W), 0) for j in range(W))] = 0
+    lead3[(lat(j+(L-W-move), 0) for j in range(W))] = 0
     lead3[lat.neighbors()] = -t  
     syst.attach_lead(lead3)