Docu issue

examples/04-2_two-sided-cavity_with-atom_coh-drive__cumulants.jl

@@ -136,9 +136,9 @@ p
 
 # In the following, we include $N=2$ two-level atoms in the cavity and simulate the transmission and reflection of a coherent Gaussian pulse with a mean photon number of $|\alpha|^2 = 1/10$. We assume that the atoms are on resonance with the cavity, i.e. $\Delta = \Delta_c = \Delta_a$.
 
-# Obtain the ModelingToolkit independent variable from a seed mean-field problem and
-# register the classical drive as a function of it (QuantumCumulants v0.5 convention).
-t = meanfield([a], -Δ*a'a, [a]).iv
+# Define the ModelingToolkit independent variable and register the classical drive as a
+# function of it.
+@independent_variables t
 @register_symbolic Et(tt)
 
 G_d_t = SLH(1, Et(t), 0)

src/SLH.jl

@@ -288,6 +288,14 @@ function ▷(G1::SLH{N}, G2::SLH{N}) where {N}
     return _build_slh(S_t, L_t, H_t, op_hint)
 end
 
+function ▷(::SLH{N1}, ::SLH{N2}) where {N1,N2}
+    throw(
+        DimensionMismatch(
+            "cannot cascade SLH systems with different numbers of ports: $N1 and $N2",
+        ),
+    )
+end
+
 ▷(a::SLH, b::SLH, c::SLH...) = ▷(a ▷ b, c...)
 
 """

test/test_SLH.jl

@@ -58,6 +58,22 @@ using Test
         @test iszero(simplify(jump_operator(G2)[1] - (gu'*au + √(γ)*c + gv'*av)))
     end
 
+    @testset "cascade port mismatch" begin
+        G_two_port = G_u ⊞ G_c
+        expected_message = "cannot cascade SLH systems with different numbers of ports: 1 and 2"
+
+        for compose in (▷, cascade)
+            exception = try
+                compose(G_u, G_two_port)
+                nothing
+            catch exception
+                exception
+            end
+            @test exception isa DimensionMismatch
+            @test exception.msg == expected_message
+        end
+    end
+
     @testset "simple_concatenate" begin
         G1 = SLH(1, gu'*au, 0)
         G2 = SLH(1, √(γ)*c, Δ*c'c)