The quantum information revolution aims at transforming information technology by engineering quantum systems, i.e. qubits, that can be used for quantum information processing (QIP), which allows to perform computations inaccessible to classical computers. In the quest for such systems, solid-state qubits alongside trapped ions currently are the leading candidates. One of the most advanced solid-state technologies to date is based on superconducting quantum circuits (SQCs), which makes use of Josephson tunnel junctions and their macroscopic quantum coherence between two superconducting islands. Due to recent advances in semiconductor-superconductor hybrid (SSH) devices, novel SSH-based qubit architectures have emerged, demonstrating improved properties compared to conventional SQCs, such as in-situ tunability while not being susceptible to flux noise. These novel SSH qubits make use of the true microscopic particle transport within SSH weak links. The main goal of the project is to unambiguously demonstrate SSH-based qubits as a viable and scalable platform for QIP by combining novel SQCs with advanced silicon-technology. The fellow will develop and characterise SSH weak links solely based on silicon (Si), which have the advantage of being fully CMOS compatible and consisting entirely of crystalline materials. Finally, these Si-based weak links will be implemented in novel SQCs, which will combine the good controllability of SQCs with the unique material quality of Si. This will allow the study of the underlying charge dynamics, giving insight into sources of loss, and offer new possibilities for complex architectures. The successful completion of this project will be a decisive landmark towards understanding and integrating such devices in larger circuits, which will be crucial a step towards a vital roadmap for their application in QIP.

We are entering the third era of computing: cognitive computing, which holds great promise in terms of deriving intelligence/knowledge from huge volumes of data. Today’s cognitive computers are based on the von Neumann architecture, in which the computing and the memory units are separated. Cognitive computing, however, is inherently data-centric, meaning that huge amounts of data need to be shuttled back and forth at high speeds, a task at which that architecture is highly inefficient. It is becoming increasingly clear that to build efficient cognitive computers, we need to transition to non-von Neumann architectures where memory and logic coexist in some form. Brain-inspired neuromorphic computing and the fascinating new area of memcomputing are two key non-von Neumann approaches being researched. The critical element in these novel computing paradigms is a very-high-density, low power, variable-state, programmable and non-volatile nanoscale memory device. A technological breakthrough that will lead us to this device will be a game-changer for cognitive computing. The goal of this project is to explore one such device concept that I co-invented at IBM Research - Zurich and which we have dubbed “projected memristor” or “projestor” for short. The projestor is indeed a memristor, i.e., a resistive element that remembers the history of the current that previously flowed through the device. The distinguishing feature of a projestor is that the physical mechanism of resistance storage is decoupled from the information retrieval process. In the first part of the project, we will design and fabricate projestor devices to establish the concept of projection and assess its merits and drawbacks. In the second part, we will expand the concept substantially to explore highly innovative projestor devices. In the third part, we will explore various applications of projestors in neuromorphic computing and memcomputing, with a particular focus on real-time data analytics.