+1 vote
asked by (180 points)
edited by

Hi Miles,

Is it possible to have superposed states like ("up" + "down")/sqrt(2.0) for spin-1/2 systems using IQTensor?

I have tried to manually set the elements, but since the divergence of different sectors are different, I am not allowed to do so. Is there any workaround for that?

I have a N-site Hamiltonian, which conserves the spin-z quantum number, and I just want to evolve the system (using Trotter decomposition) with initial product state which has superposed states (like the above) at every site.

with regards,
Titas

1 Answer

0 votes
answered by (27.6k points)

Hi Titas,
Thanks for the question. My initial reaction is that this just isn't what the IQTensor system is intended for. What you are asking for is to create a state which doesn't have well-defined quantum numbers but still use tensors which keep track of the (non-existent) quantum numbers. Such tensors would not be block-sparse in your case so all of the extra IQTensor bookkeeping, even if it was allowed, would just slow down the code for no advantage.

I hope that answer is helpful. Are you ok with just using ITensors and MPS for your case rather than IQTensors and IQMPS?

Best regards,
Miles

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