Date and Time:  11-Aug-2023 10am

Speaker:  Dr. Wei Huang ,Senior Scientific Assistant, ETH Zürich, Switzerland

Host: Jiyin Wang (BAQIS）

Title:  Quantum information processing in group IV materials

Abstract: 

Semiconductor quantum dots present a viable technology for mass-manufacturing, due to their compatibility with modern chip fabrication processes. They are widely regarded as one of the prime candidates for enabling quantum computing, a fact which has garnered the attention and participation of many globally recognized semiconductor corporations such as Intel, IBM, and CEA Leti.

Group IV semiconductor materials exhibit varying strengths in spin-orbit coupling, allowing for different frequencies of Rabi oscillations and coherence times. Experiments have been conducted with quantum computing on various Group IV materials.

Graphene, serving as the host material for spin qubits, possesses a lower natural concentration of nuclear spin and weak spin-orbit interaction, resulting in reduced magnetic and electrical noise. Silicon, with purifiable isotopes, allows the purified silicon substrate to significantly decrease the noise produced by nuclear spins, thereby facilitating precise manipulation of logic gates. While silicon-based transistor technology is well-established, germanium, initially abandoned by the industry due to its lack of stable natural oxide, has re-emerged with the advent of germanium-compatible high-permittivity dielectrics. As a high-mobility semiconductor, germanium has once again captured the interest of the semiconductor industry.

In this presentation, the speaker will review and share recent advancements in quantum dot-based electron spin qubits across various materials, encompassing the achievement of high-fidelity readouts, logic gates, and the implementation of multi-qubit systems.

About the Speaker:

The speaker completed his PhD and postdoc at the University of New South Wales in Australia, specializing in silicon qubits. His portfolio covers the development and characterization of quantum dot spin qubits in various materials, including bilayer graphene, silicon, and planar germanium. His research notably includes the implementation of high-fidelity two-qubit logic gates in silicon quantum dots, thorough characterization of noise sources in silicon MOS qubits, and groundbreaking work on exploring silicon qubit scalability. Now a Senior Scientist at ETH Zürich, he is at the helm of pioneering experiments in spin qubit readout for bilayer graphene quantum dots and in the creation of quantum dots in planar germanium heterostructures. His substantial achievements have been featured in high-impact journals such as Nature, Nature Nanotechnology, and Physical Review Letters.