Tom O'Brien

Results 13 comments of Tom O'Brien

hermitian conjugate in odd location

That would be great if you could give it a first pass. I think expanding the Hermitian conjugate function to a general PolynomialTensor class is probably a good idea, even...

smbolic_operator.py::_issmall() could (should?) be a static member of SymbolicOperator

I can't see any potential issues with this. Do you want to make the change?

get_sparse_operator does not handle DOCIHamiltonian objects as expected

So, a DOCIHamiltonian has a representation in fermion form (where it has twice as many spin orbitals) and one in qubit form (which we have correct). It was my intention...

Adding type hints

Hi @jitendrs - I guess it's probably best to start adding hints to some of the higher level locations - say transforms, hamiltonians, and circuits. Basically just add the hints,...

Angle of rotation in trotterize_exp_qubop_to_qasm is off by a factor of 2

I have a feeling that this is an issue with the definition of 'Rz' - some people would say 'Rz(theta)=exp(1j * Z * theta)', some people would say 'Rz=exp(-1j *...

Angle of rotation in trotterize_exp_qubop_to_qasm is off by a factor of 2

Yes, this would be good to implement - been difficult to find the time to do this though, as this more standard Trotterization isn't so state-of-the-art anymore. You can definitely...

On finding an upper bound to the norm of the Hamiltonian

I take it that by norm you mean spectral norm / largest eigenvalue? Bounding this well is hard. The bounds I know of is the Frobenius norm that you mentioned,...

On finding an upper bound to the norm of the Hamiltonian

Not sure that I follow why ||H||/lambda

Allowing more general indices for SymbolicOperator

Thanks for the quick reply, and that's a useful link. I agree with the worries about implementation + maintenance, which is why I figured raising the issue for discussion might...

Our importing strategy needs some work

Looking around, it appears that the solution to this is 'dont have everything depend on each other'. Lol - easier said than done. However, maybe this is something we need...