Superfluid helium is a quantum liquid that exhibits a range of counter-intuitive phenomena such as frictionless flow. Quantized vortices are a particularly important feature of superfluid helium, and all superfluids, characterized by a circulation that can only take prescribed integer values. However, the strong interactions between atoms in superfluid helium prohibit quantitative theory of vortex behaviour. Experiments have similarly not been able to observe coherent vortex dynamics.
This thesis resolves this challenge, bringing microphotonic techniques to bear on two-dimensional superfluid helium, observing coherent vortex dynamics for the first time, and achieving this on a silicon chip. This represents a major scientific contribution, as it opens the door not only to providing a better understanding of this esoteric quantum state of matter, but also to building new quantum technologies based upon it, and to understanding the dynamics of astrophysical superfluids such as those thought to exist in the core of neutron stars.
Superfluid helium is a quantum liquid that exhibits a range of counter-intuitive phenomena such as frictionless flow. Quantized vortices are a particularly important feature of superfluid helium, and all superfluids, characterized by a circulation that can only take prescribed integer values. However, the strong interactions between atoms in superfluid helium prohibit quantitative theory of vortex behaviour. Experiments have similarly not been able to observe coherent vortex dynamics.
This thesis resolves this challenge, bringing microphotonic techniques to bear on two-dimensional superfluid helium, observing coherent vortex dynamics for the first time, and achieving this on a silicon chip. This represents a major scientific contribution, as it opens the door not only to providing a better understanding of this esoteric quantum state of matter, but also to building new quantum technologies based upon it, and to understanding the dynamics of astrophysical superfluids such as those thought to exist in the core of neutron stars.
Nominated as an outstanding Ph.D. thesis by The University of Queensland, Australia Introduces a new microphotonic paradigm of probing microscopic behaviour of two-dimensional superfluid helium Presents a set of measurements of superfluid dynamics in new regimes which, until this work, were thought to be experimentally inaccessible Provides a comprehensive and clear introduction covering the basics of superfluidity, cavity optomechanics, and whispering-gallery-mode resonators
Yauhen Sachkou
2D Quantum Fluid Two-Dimensional Superfluid 2D Superfluid Helium Third Sound Quantized Vortex Vortex Dynamics Topological Phase Transition Cavity Optomechanics Whispering-Gallery-Mode Resonator quantum liquid astrophysical superfluids