报告题目：Supercurrents at finite magnetic field in InSb nanowires

报 告 人：Vincent Mourik，Niels Stensen Fellow at the University of New South Wales, Australia

报告时间：2016年8月30日15：00

报告地点：理科楼C109会议室

报告摘要：In the first half of my seminar, I will present an ongoing effort from my PhD research:

Supercurrents at finite magnetic field in InSb nanowires

The engineering of topological superconductors and the observation and control of their non-abelian quasiparticles is a dominant effort in condensed matter physics, both out of fundamental interest and for their potential application in topological quantum computing. A one-dimensional semiconducting nanowire with strong spin-orbit interaction that is proximity coupled to a standard s-wave superconductor is a particularly attractive implementation of a topological superconductor due to its relative ease of fabrication. One of the prime signatures of the existence of Majorana fermions in such a structure would be the observation of the 4pi Josephson effect. Furthermore, several proposed braiding schemes heavily rely on good quality Josephson junctions working at considerable magnetic field strengths. I will present the typical behavior we found of the supercurrent in such nanowires, along with our current insights in the physical interpretation of our observations.

In the second half of my presentation, I want to shift focus to my new post-doctoral research topic:

The emergence of chaos in a single spin in silicon

Classical conservative systems usually exhibit rapid dispersion of initial conditions – chaos – while the quantum version of the same systems exhibit quasi-periodicity, localization and tunneling through classically forbidden regions of phase space. How to reconcile this strikingly different behavior has been the topic of much theoretical debate, but little experimental proof, and none whatsoever on a single quantum system observed in real time. My project aims at achieving the first real-time experimental observation of the quantum dynamics of a single classically chaotic system – a periodically-driven non-linear top. This I want to achieve by combining the existing infrastructure for donor based spin qubit in silicon in the group of Prof. Morello at the University of New South Wales with a new type of donor, having a large nuclear spin and a non-linearity due to nuclear quadrupole interaction. I will outline the upcoming experiments and discuss their theoretical modelling.