Coherent phonon source based on electron spin resonance in a quantum-dot qubit.

One of the key requirements for quantum phononics, especially for scenarios involving quantum communication and quantum-state transduction, is the implementation of a controlled phonon source, ultimately with the capacity to source single phonons at some desired generation rate. In this article, we describe a scheme for the controlled sourcing of phonons that exploits an electron-spin resonance between the Zeeman-split levels of a gated quantum dot. This on-chip scheme allows for broad tunability of the energy of the generated phonons, with convenient electrical control. By providing a compact and coherent source, this scheme is also well suited to the construction of more-extended phononic circuits, involving the sourcing, transmission and detection of phononic signals.