3

i want to know what is a x-type density matrix structure? i want to know the general case of it. is this something like this?

enter image description here

can one of matrix elements be 0? unfortunately there is no info about it in google. also i want know under what conditions a x-type state is entanglement?

glS
  • 24,708
  • 5
  • 34
  • 108
reza
  • 689
  • 2
  • 9

1 Answers1

2

The answer is essentially just, yes. Though of course there will be some constraints on those coefficients, to ensure you get an Hermitian positive-semidefinite unit-trace matrix.

See e.g. Quesada et al. 2012 for more info about the properties of $X$ states.

glS
  • 24,708
  • 5
  • 34
  • 108