Spin Dynamics Forum

SpinDynamica support => Examples => Topic started by: MalcolmHLevitt on May 28, 2015, 05:34:50 PM

Title: Product operator calculations
Post by: MalcolmHLevitt on May 28, 2015, 05:34:50 PM
I get quite a few queries asking how one can do product operator calculations for weakly coupled systems using SpinDynamica. I attach a file showing a few examples, including INADEQUATE in a 2-spin-1/2 system and INEPT in an A3X system.

The file also includes a product operator calculation for spin-3/2. Such calculations are not easy to do by hand.
Title: Re: Product operator calculations
Post by: jdumez on June 03, 2015, 01:41:27 PM
Thanks, this type of calculation is very useful indeed.

In an attempt with a four-spin system, a surprising timing is observed for the application of a hard pi pulse (see attached notebook). RotationSuperoperator takes much longer (10s of seconds) than the explicit exponential of a commutation superoperator. Is there a syntax that would be both fast and general?

Title: Re: Product operator calculations
Post by: MalcolmHLevitt on June 05, 2015, 09:31:51 AM
Hi Jean-Nicolas,
 I have looked at this and while temporary fixes are possible I prefer to do some more major restructuring to avoid the repeated and time-consuming pattern matching loops which are responsible for this slow execution of symbolic code for more than a very small number of spins. I will get round to this but it may take some time. In the meantime please do use the shortcut you found.
 sorry for the delay
malcolm
Title: Re: Product operator calculations
Post by: MalcolmHLevitt on December 21, 2015, 10:40:41 PM
Hi Jean-Nicolas,
 The timing issues you raise should have been addressed in v2.14.1
malcolm