Achieving quantum control through messenger flying excitons

Gigahertz surface acoustic waves show tremendous potential in quantum communication networks due to their versatility. Yuan et al. experimentally reviewed the interplay between acoustic waves and elementary excitations for quantum information processing.

Semiconductors subjected to surface acoustic waves experience dynamic deformation which can capture and transport neutral electron-hole pairs called excitons. Controlled information transfer can be achieved using these flying excitons as on-chip messengers. The excitons can then be easily interconverted to photons.

“Acoustic wave devices are usually viewed as a technology for radio-frequency engineering, while excitons are treated as a playground for fundamental physics,” said Mingyun Yuan. “This review shows that a bridge can be built in between and generate new functionalities.”

The authors showcase the possibilities of acoustic exciton manipulation. High-frequency acoustic transducers on doped gallium arsenide nanostructures and the identification of two-level centers have proven capable of storing and manipulating single excitons. In combination, these features demonstrated GHz single-photon sources pumped by acoustic waves.

Future studies will focus on the quantum nature of the surface acoustic waves as well as new material systems promising room-temperature operation. Acoustic exciton transport studies have, until very recently, required cryogenic temperatures to reach the ground state of GHz quanta. These studies can now be extended to room temperature by using ensembles with high binding energy formed in transition metal dichalcogenide structures.

“Another exciting direction is to reach the quantum regime, for example achieving single phonon control for the on-chip transfer of quantum information and exciton spin manipulation,” said Yuan.

Source: “Manipulation of flying and single excitons by GHz surface acoustic waves,” by Mingyun Yuan, Klaus Bierman, and Paulo V. Santos, AVS Quantum Science (2022). The article can be accessed at https://doi.org/10.1116/5.0095152 .

This paper is part of the Quantum Acoustics Collection, learn more here .