fixes QuEraComputing#951

tests/test_z2_compile.py

@@ -5,16 +5,34 @@
 def test_z2_compile():
     # Define relevant parameters for the lattice geometry and pulse schedule
     n_atoms = 11
-    lattice_spacing = 6.1
-    min_time_step = 0.05
+    lattice_spacing = 6.1 # (μm)
+    min_time_step = 0.05 # (μs)
 
-    # Define Rabi amplitude and detuning values.
-    # Note the addition of a "sweep_time" variable
-    # for performing sweeps of time values.
+    # Choose a max Rabi amplitude of 15.8 MHz... pretty high.
+    # This way, we minimize the protocol duration, 
+    # but maintain the same pulse area, Ω*t.
     rabi_amplitude_values = [0.0, 15.8, 15.8, 0.0]
+
+    # The lattice spacing and Rabi amplitudes give us a nearest-neighbor interaction strength:
+        # V_{i}{i+1} = 105 MHz >> 15.8 MHz = Ω
+    # Our interaction strength for next-nearest-neighbor is quite low comparitively:
+        # V_{i}{i+2} = 1.64 MHz << 15.8 MHz = Ω
+    # So far, this looks good for creating a Z2 topology
+
+    # Next, define the detuning values
     rabi_detuning_values = [-16.33, -16.33, 16.33, 16.33]
+
+    # We start at negative values to push the atom into ground state
+    # We sweep to positive values to try and push the atom into Rydberg state
+    # This gives us a static Rydberg blockade radius R_b = 8.32μm
+    # Typically, we set lattice_spacing < R_b for a better blockade approximation
+    # that no two atoms within lattice_spacing are both in the Rydberg state
+
+    # Note the addition of a "sweep_time" variable
+    # for performing sweeps of time values.
     durations = [0.8, "sweep_time", 0.8]
 
+    # Create chain formation of our atoms and piecewise pulse shapes
     time_sweep_z2_prog = (
         Chain(n_atoms, lattice_spacing=lattice_spacing)
         .rydberg.rabi.amplitude.uniform.piecewise_linear(
@@ -31,6 +49,7 @@ def test_z2_compile():
         sweep_time=np.linspace(min_time_step, 2.4, 20)
     )
 
+    # Query on emulators and Aquila...
     bloqade_emu_target = time_sweep_z2_job.bloqade.python()
     braket_emu_target = time_sweep_z2_job.braket.local_emulator()
     quera_aquila_target = time_sweep_z2_job.parallelize(24).quera.aquila()
@@ -43,5 +62,6 @@ def test_z2_compile():
         braket_aquila_target,
     ]
 
+    # And, compile!
     for target in targets:
-        target._compile(10)
+        target._compile(10)