Comment #5 on issue 3199 by [email protected]: Finish implementing density operator/matrix
http://code.google.com/p/sympy/issues/detail?id=3199

Here is the summary of Trace/Partial Traces operations and related methods that
would be needed. Please review.

Trace operation functionality in quantum module ( including partial trace )

a. A generic Tr expression that takes a matrix , as the operand. This will inherit from Expr. ( we still need to determine a closest Expr to use as template ).

Tr(matrix) = general trace formula, can use existing matrix function.

b. Tr( A \otimes B )  = Tr(A)Tr(B)
 Same applies to > 2 tensor products.

The general density operator will have
______________________________________


1. Partial Trace function of following form in the density operator class:
TrPartial( density operator of set of tensor products , offset/offset range to
  trace)

eg. TrPartial( density( a_1 \otimes b_1, a_2 \otimes b_2, ..), 0) to trace B TrPartial( density( a_1 \otimes b_1 \otimes c_1, a_2 \otimes b_2 \otimes c_2, ..), 1,2) to trace BC

      where a_i \in A, b_i  in \B , c_i  in C


(alternatively, should we create a partial trace expression?).


Qubit Density Operator
______________________


The qubit density operator,will also have a partial trace function

The qubit density operator can have sequence of 1-qubit states, n-qubit states(as tensor products, or qubits)

1. TrPartial ( density_operator( ) , range of qubits to trace ).


--
You received this message because you are subscribed to the Google Groups 
"sympy-issues" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/sympy-issues?hl=en.

Reply via email to