add tests

Author: TendonFFF

test/core-test/brme.jl

@@ -0,0 +1,123 @@
+@testset "Bloch-Redfield tensor sec_cutoff = $sec_cutoff" for sec_cutoff in [0,0.1,1,3,-1]
+    N = 5
+    H = num(N)
+    a = destroy(N)
+    A_op = a+a'
+    spectra(x) = (x>0) * 0.5
+
+    R = bloch_redfield_tensor(
+        H,
+        [(A_op, spectra)],
+        [a^2],
+        sec_cutoff=sec_cutoff,
+        fock_basis=true
+    )
+    R_eig, evecs = bloch_redfield_tensor(
+        H,
+        [(A_op, spectra)],
+        [a^2],
+        sec_cutoff=sec_cutoff,
+        fock_basis=false
+    )
+    @test isa(R, QuantumObject)
+    @test isa(R_eig, QuantumObject)
+    @test isa(evecs, QuantumObject)
+    state = rand_dm(N) |> mat2vec
+    fock_computed = R * state
+    eig_computed = (sprepost(evecs, evecs') * R_eig * sprepost(evecs', evecs)) * state
+
+    @test isapprox(fock_computed, eig_computed, atol=1e-15)
+end;
+
+@testset "brterm lindblad" begin
+    N = 5
+    H = num(N)
+    a = destroy(N) + destroy(N)^2/2
+    A_op = a+a'
+    spectra(x) = x>0
+    
+    # this test applys for limited cutoff
+    lindblad = lindblad_dissipator(a)
+    computation = brterm(H, A_op, spectra, sec_cutoff=1.5, fock_basis=true)
+    @test isapprox(lindblad, computation, atol=1e-15)
+end;
+
+@testset "brterm basis for sec_cutoff = $sec_cutoff" for sec_cutoff in [0,0.1,1,3,-1]
+    N = 5
+    H = num(N)
+    a = destroy(N) + destroy(N)^2/2
+    A_op = a+a'
+    spectra(x) = x>0    
+    
+    R = brterm(
+        H,
+        A_op,
+        spectra,
+        sec_cutoff=sec_cutoff,
+        fock_basis=true
+    )
+    R_eig, evecs = brterm(
+        H,
+        A_op,
+        spectra,
+        sec_cutoff=sec_cutoff,
+        fock_basis=false
+    )
+    @test isa(R, QuantumObject)
+    @test isa(R_eig, QuantumObject)
+    @test isa(evecs, QuantumObject)
+    state = rand_dm(N) |> mat2vec
+    fock_computed = R * state
+    eig_computed = (sprepost(evecs, evecs') * R_eig * sprepost(evecs', evecs)) * state
+
+    @test isapprox(fock_computed, eig_computed, atol=1e-15)
+end;
+
+f(x) = exp(x)/10
+function g(x) 
+    nbar = n_thermal(abs(x), 1)
+    if x > 0
+        return nbar
+    elseif x < 0
+        return 1 + nbar
+    else
+        return 0.
+    end
+end
+
+spectras = [
+    (x -> (x>0), "positive frequency filter"),
+    (x -> one(x), "no filter"),
+    (f, "smooth filter"),
+    (g, "thermal field")
+]
+
+@testset "brterms sprectra with $description" for (spectra, description) in spectras
+    N = 5
+    H = num(N)
+    a = destroy(N) + destroy(N)^2/2
+    A_op = a+a'
+
+    R = brterm(
+        H,
+        A_op,
+        spectra,
+        sec_cutoff=0.1,
+        fock_basis=true
+    )
+    R_eig, evecs = brterm(
+        H,
+        A_op,
+        spectra,
+        sec_cutoff=0.1,
+        fock_basis=false
+    )
+    @test isa(R, QuantumObject)
+    @test isa(R_eig, QuantumObject)
+    @test isa(evecs, QuantumObject)
+    state = rand_dm(N) |> mat2vec
+    fock_computed = R * state
+    eig_computed = (sprepost(evecs, evecs') * R_eig * sprepost(evecs', evecs)) * state
+
+    @test isapprox(fock_computed, eig_computed, atol=1e-15)
+end;