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Kronecker tensor product of two or more matrices

Other toolboxes required none
Related functions TensorSum
Function category Basic operation

Tensor is a function that produces the Kronecker (tensor) product of two or more matrices, and thus extends MATLAB's built-in kron function.


  • KRN = Tensor(A)
  • KRN = Tensor(A,M)
  • KRN = Tensor(A,B,C,...)

Argument descriptions

  • A: If A is a cell, then KRN is the Kronecker product of all matrices within A.
  • M (optional): A scalar indicating how many times A should be tensored with itself (if M is provided, A must be a matrix).
  • B,C,... (optional): Matrices. If these are provided, then A must be a matrix, and the output is $A \otimes B \otimes C \otimes \cdots$.


Several different input formats

The Tensor function accepts input in many different formats, so that you may use whichever is most convenient at a particular time. For example, the following three code snippets all result in the same operator: Tensor(A,3), Tensor(A,A,A), and Tensor({A,A,A}).

Multiple copies of Werner states

When investigating the NPPT bound entanglement conjecture, you may want to tensor Werner states with themselves multiple times. The following code tensors a particular Werner state with itself 6 times:

>> rho = WernerState(3,1/2);
>> rho6 = Tensor(rho,6);

Note that rho6 is a 531441-by-531441 matrix, so we don't display it here.

Source code

Click here to view this function's source code on github.