Studying propagating acoustic waves at the single phonon level.

The project aims at studying propagating surface acoustic waves at the single phonon level. In a yet unoptimized experiment we have recently been able to show extraordinary sensitivity to mechanical waves. Using the extreme charge sensitivity of a Radio Frequency Single Electron transistor (RF-SET) and coupling charge to mechanical displacement via the piezoelectric properties of GaAs, we have demonstrated a displacement sensitivity of 30 am/vHz. We have used this to study propagating Surface Acoustic Saves (SAW) with a frequency of 1GHz on the surface of GaAs. The speed of the RF-SET has allowed us to follow SAW pulses in time as they pass the SET. Furthermore, pulses containing less than a single phonon can be detected by averaging many times. We aim at optimizing our set up and study propagation of phonons at the single phonon level. This is a long term project with the overall objective is to study quantum properties of single propagating phonons. Specifically we aim at: - Improving the sensitivity to allow single shot detection of a single phonon, i.e. without averaging. - Make beam splitters for phonons that will allow interference experiments. - Implement dual detectors that will allow correlation measurements. - Study phonons in high-Q SAW cavities. - Coupling the phonons to superconducting qubits.

Participants

Per Delsing (contact)

Professor vid Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Funding

Swedish Research Council (VR)

Funding years 2012–2014

More information

Latest update

2016-02-28