Computing specific heat

Question

Dear Miles,

is there an easy way in ITensor to compute the specific heat of a chain? Namely is the operator H^2 already implemented somewhere or could it be generated easily with AutoMPO?

Thanks a lot!

All the best,
Jacopo

Answer 1

Hi Jacopo,

To create @@H^2@@, you could always create @@H@@ with AutoMPO and then use the function nmultMPO to multiply the MPO @@H@@ with itself.

Otherwise, to use AutoMPO, you would have to write out by hand all of the terms resulting from @@H^2@@, and input those terms into AutoMPO. This shouldn't be too bad for a Hamiltonian with local interactions.

Cheers,
Matt