Observation of two 𝓟𝓣 transitions in an electric circuit with balanced gain and loss★
School of Physics and Astronomy, Sun Yat-sen University, Zhuhai, Guangdong 519082, P.R. China
2 Department of Physics, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, IN 46202, USA
3 School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou, Guangdong 510006, P.R. China
Received in final form: 3 June 2020
Published online: 4 August 2020
We investigate 𝓟𝓣-symmetry breaking transitions in a dimer comprising two LC oscillators, one with loss and the second with gain. The electric energy of this four-mode model oscillates between the two LC circuits, and between capacitive and inductive energy within each LC circuit. Its dynamics are described by a non-Hermitian, 𝓟𝓣-symmetric Hamiltonian with three different phases separated by two exceptional points. We systematically measure the eigenfrequencies of energy dynamics across the three regions as a function of gain-loss strength. In addition to observe the well-studied 𝓟𝓣 transition for oscillations across the two LC circuits, at higher gain-loss strength, transition within each LC circuit is also observed. With their extraordinary tuning ability, 𝓟𝓣-symmetric electronics are ideally suited for classical simulations of non-Hermitian systems.
© EDP Sciences / Società Italiana di Fisica / Springer-Verlag GmbH Germany, part of Springer Nature, 2020