Hi, I see two ways to address this problem
- You can use Tkwant and indeed do a FFT afterwards. It works but it is somewhat overkill and cumbersome. However, one advantage of this approach is that if you use self-consistent Tkwant, you will be able to take interactions effect at a level equivalent to RPA which is important for these types of calculaitons - You can use Kwant and one of the many formula that relates its outputs to finite frequency conductivities. See e.g. the following references to find them: * https://arxiv.org/abs/1802.05924 * https://arxiv.org/abs/1211.2768 (this will involve computing an integral over energy of some object calculable with Kwant). Hope it helps, Xavier > Le 17 juil. 2023 à 04:20, X.-X. Zhang <xiaoxiao.zh...@riken.jp> a écrit : > > Hello Kwant community, > The Kwant package deals with the (dc) linear response for tight-binding > models while TKwant is time-dependent. But it is not obvious to me from the > documentation whether TKwant is capable of simulating nonlinear responses (at > finite frequencies). Instead of naively assuming that it does not go beyond > linear Kwant, it is probably worth asking here. > > I'm particularly interested in finding nonlinear conductivities like a > second-harmonic sigma(2w; w, w) and a dc response sigma(0; w, -w) with w the > driving frequency. They are generated, e.g., by applying the ac bias driving > voltage/current through the attached leads. If Tkwant does capture all such > nonlinear effects, I presume one can simulate in the real time and transform > the current/voltage response to the frequency space and obtain these results. > > Any relevant comment will be appreciated!
