Anisoptropy and Mixing of Surface Acoustic Waves*

Surface acoustic waves (SAW), in particular Rayleigh waves near the surface of a piezoelectric material, have attracted a lot of attention lately through their abilities to carry electrons, and to couple strongly with superconducting qubits and possibly spin qubits. 

While SAW could be useful for quantum control and quantum transduction, they could also potentially lead to qubit decoherence.  

Here we report a theoretical study of the angular dependence of different SAW modes, such as Rayleigh wave and Gulyaev wave coupled to both sagittal and transverse electric fields. 

In particular, we investigate the mixing between Rayleigh wave and Gulyaev wave for directions between the (110) and (100) axes. 

Our results represent an initial step toward a comprehensive understanding of coupled qubit-SAW dynamics.