A Journey on Quantum Sound

Abstract

Recently, quantum networks have emerged as a focal point of research and discussion due to their promise in overcoming the limitations of classical networks, offering unparalleled capabilities in secure communication, quantum computation, and distributed quantum information processing. Simply speaking, a quantum network is a network in which the nodes are capable of storing and processing quantum information and communicate via quantum channels. Unlike classical computers and networks, in which components at nodes and the interconnections between them are mostly made of electronics circuits, there is not a homogeneous system for all the applications in a quantum network. This in particular, increases the need for implementation of heterogeneous quantum systems. An important milestone in the development of hybrid quantum networks are the interconnections between different components at the nodes, which serve as quantum channels. A quantumchannel is an interconnection between two quantum systems that can route carriers of quantum information, while preserving their coherence over the routing process. Finding such a channel, with carriers having the ability to couple to different quantum systems is not trivial. Although quanta of mechanical vibrations - known as "phonons" - have shown great potential for this task, as they can couple to many different types of quantumsystems.
The aim of this thesis is to design an integrated platform using highly confined GHz phonons, with scalability as a primary consideration. This platform serves as an on-chip phononic quantum channel, enabling the ability to perform on-chip operations directly on single phonons on a chip. Moreover, the designed structures in this thesis are advantageous for advanced quantum acoustics experiments and pave the way towards having full coherent control on phonons on a chip.