+1 vote
asked by (610 points)

Dear all

How to create local identity operator at site j? Indirectly, one can use the identity "S^zjS^zj" or "projUp+projDn", which have built-in functions like op("Z",sites,j) and op("projDn",sites,j). Is there a more standard way?

Moreover, how about high-spin sites, fermion/electron sites?


1 Answer

+1 vote
answered by (70.1k points)

Hi Junsen,
You can use the operator name "Id" to do this. So like op("Id",sites,j) or alternatively op("Id",ind) where ind is a Index object.

This particular operator ("Id") is actually defined for all indices, not just ones carrying special tags.

Hope that is the answer you need -


commented by (610 points)
thank you Miles, that's what I need :)
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