Experimental simulation of negative entanglement entropy scaling with electrical circuits

The entanglement entropy (EE) represents an operationally defined entanglement measure which has been widely applied in Hermitian systems such as black holes and quantum many-body systems. Recently, interest has also shifted to the entanglement properties of non-Hermitian systems. It has been theoretically predicted that negative EE scaling can enigmatically arise in non-Hermitian free-fermion lattices hosting exceptional points. However, experimental simulation of such a theoretical prediction remains a challenge. Here, we report an experimental simulation of negative EE scaling using an electrical circuit platform, where the requisite nonreciprocal long-range couplings can be engineered precisely. By measuring resonant voltage profiles, the corresponding simulated negative EE scaling can be demonstrated. Our work paves the way for simulating analogs of probability for nonconserving negative entanglement processes in classical systems.