Giant nonlinearity via breaking parity-time symmetry: a route to low-threshold phonon diodes

Understand

Nonreciprocal devices that permit wave transmission in only one direction are indispensible in many fields of science including, e.g., electronics, optics, acoustics, and thermodynamics.

• Manipulating phonons using such nonreciprocal devices may have a range of applications such as phonon diodes, transistors, switches, etc.
• One way of achieving nonreciprocal phononic devices is to use materials with strong nonlinear response to phonons.
• However, it is not easy to obtain the required strong mechanical nonlinearity, especially for few-phonon situations.