I am coding in C++.

I am interested in performing the time evolution of an open quantum system. In doing so, I want to adopt the stochastic unravelling of the quantum master equation.

I would like to adopt the TEBD algorithm and I need apply a two-site gate given by the exponential of a non-hermitian operator.

I have a couple of questions:

1) Can the procedure in http://itensor.org/docs.cgi?vers=cppv3&page=formulas/tevol_trotter be applied for non-hermitian Hamiltonian?

2) Is there a built-in function to perform the exponential (as you would do for a hermitian operator)? Should I simply rely in the expansion exp(-i t H) \approx 1 - itH + ...?

Thank you in advance for your help!