# decouple.m

Obliterates all interactions and populations in the subspace of states that involve the specified spins in any way. The specified spins would not contribute to the system dynamics until the Liouvillian is rebuilt from scratch.

## Syntax

    [L,rho]=decouple(spin_system,L,rho,spins)


## Arguments

    L     - Liouvillian superoperator, this may be left empty

rho   - state vector or a horizontal stack thereof, this
may be left empty

spins - spins to be wiped, specified either by name, e.g.
{'13C','1H'}, or by a list of numbers, e.g. [1 2]


## Outputs

    rho   - state vector(s) with all populations of the
states involving the target spins set to zero

L     - Liouvillian superoperator with all terms in-
volving the target spins set to zero


## Notes

1. This function is an analytical equivalent of a perfect decoupling pulse sequence on the specified spins.
2. This function requires sphten-liouv formalism and supports Fokker-Planck direct products.