GisinState

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GisinState
Produces a two-qubit Gisin state

Other toolboxes required none
Function category Special states, vectors, and operators

GisinState is a function that produces a two-qubit "Gisin state", as defined in [1], which has the following standard basis representation: \[\rho_{\lambda,\theta} := \lambda\begin{bmatrix}0 & 0 & 0 & 0 \\ 0 & \sin^2(\theta) & -\sin(\theta)\cos(\theta) & 0 \\ 0 & -\sin(\theta)\cos(\theta) & \cos^2(\theta) & 0 \\ 0 & 0 & 0 & 0\end{bmatrix} + \frac{1-\lambda}{2}\begin{bmatrix}1 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 \\ 0 & 0 & 0 & 1\end{bmatrix}.\]

Syntax

  • GISIN_STATE = GisinState(LAMBDA,THETA)

Argument descriptions

  • LAMBDA: A real number between 0 and 1.
  • THETA: A real number.

Examples

The following code generates the Gisin state $\rho_{0.5,1}$:

>> GisinState(0.5,1)

ans =

    0.2500         0         0         0
         0    0.3540   -0.2273         0
         0   -0.2273    0.1460         0
         0         0         0    0.2500

Source code

Click on "expand" to the right to view the MATLAB source code for this function.

References

  1. N. Gisin. Hidden quantum nonlocality revealed by local filters. 1996. doi:10.1016/S0375-9601(96)80001-6