Useful stim references.

Signed-off-by: Stefan Krastanov <stefan@krastanov.org>

Author: Krastanov

src/QuantumClifford.jl

@@ -1381,7 +1381,7 @@ function LinearAlgebra.inv(c::CliffordOperator; phases=true)
         end
     end
     if phases
-        ci*c*ci # TODO can this be skipped
+        ci*c*ci # TODO perform this inplace as in Stim https://github.com/quantumlib/Stim/blob/e51ea66d213b25920e72c08e53266ec56fd14db4/src/stim/stabilizers/tableau.cc#L383
     else
         ci
     end

src/symbolic_cliffords.jl

@@ -4,6 +4,9 @@ abstract type AbstractSymbolicOperator <: AbstractCliffordOperator end
 abstract type AbstractSingleQubitOperator <: AbstractSymbolicOperator end
 abstract type AbstractTwoQubitOperator <: AbstractSymbolicOperator end
 
+# Stim has a good list of specialized single and two qubit operations at https://github.com/quantumlib/Stim/blob/e51ea66d213b25920e72c08e53266ec56fd14db4/src/stim/stabilizers/tableau_specialized_prepend.cc
+# Note that their specialized operations are for prepends (right multiplications), while we implement append (left multiplication) operations.
+
 """A "symbolic" Hadamard operator which permits faster multiplication than an operator expressed as an explicit tableau.
 
 ```jldoctest