minimal example for tempo only (no mean-field)

examples/tempo.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python
+# coding: utf-8
+import sys
+sys.path.insert(0,'.')
+
+import numpy as np
+import matplotlib.pyplot as plt
+
+import oqupy
+import oqupy.operators as op
+
+# ----------------------------------------------------------------------------
+
+omega_cutoff = 5.0
+a = 0.1
+temperature = 0.1
+initial_state = oqupy.operators.spin_dm("z-")
+field = 1.0 + 1.0j
+
+# System parameters
+gn = 0.2    # Twice Rabi splitting
+gam_down = 0.01 # incoherent loss
+gam_up   = 0.01 # incoherent gain
+Sx=np.array([[0,0.5],[0.5,0]])
+wc=0.0
+kappa=0.1
+end_time=1#.1
+def H(t):
+    return 2.0 * gn * np.abs(field) * Sx
+
+system = oqupy.TimeDependentSystem(H)
+correlations = oqupy.PowerLawSD(alpha=a, 
+                                zeta=1, 
+                                cutoff=omega_cutoff, 
+                                cutoff_type='gaussian', 
+                                temperature=temperature)
+bath = oqupy.Bath(oqupy.operators.sigma("z")/2.0, correlations)
+
+
+tempo_parameters = oqupy.TempoParameters(dt=0.1, dkmax=20, epsrel=10**(-7))
+
+tempo_sys = oqupy.Tempo(system=system,
+                        bath=bath,
+                        initial_state=initial_state,
+                        start_time=0.0,
+                        parameters=tempo_parameters)
+dynamics = tempo_sys.compute(end_time=end_time)
+with np.printoptions(precision=4):
+    for i,t in enumerate(dynamics._times):
+        print('t = {:.1f}\nState\n{}'.format(t,  dynamics._states[i]))
+