Fig. 2: Implementation of acoustic non-Hermitian non-reciprocal coupling.
From: Acoustic non-Hermitian skin effect from twisted winding topology
a Photograph of two acoustic resonators (labeled by “1” and “2”) connected by two cross-linked narrow waveguides. The non-reciprocal coupling is implemented by an amplifier (equipped with a DC power supply), a microphone (input), and a speaker (output). A source and a detector are used to measure the transmission. b Simplified tight-binding model for the setup in (a). c Simulated acoustic pressure field distribution of the dipole mode in a single resonator. d, e Experimentally measured (circles) and numerically fitted (solid lines) transmission spectra for samples without and with the amplifier, respectively. The blue dashed line denotes the unity of transmission.
