This thesis reports the discovery of relativistic stellar explosions outside of the gamma ray band, using optical time domain surveys. It is well known that some massive stars end their lives with the formation of a compact object (a neutron star or black hole) that launches a relativistic jet detectable from earth as a burst of gamma rays. It has long been suspected, however, that gamma ray bursts are only the tip of the iceberg in a broad landscape of relativistic explosions, and so the results presented in this thesis represent a major breakthrough. Highlights of this thesis...

This book provides guidelines and design rules for developing high-performance, low-cost, and energy-efficient quantum-dot (QD) lasers for silicon photonic integrated circuits (PIC), optical frequency comb generation, and quantum information systems. To this end, the nonlinear properties and dynamics of QD lasers on silicon are investigated in depth by both theoretical analysis and experiment.This book aims at addressing four issues encountered in developing silicon PIC:1) The instability of laser emission caused by the chip-scale back-reflection. During photonic integration, the chip-scale...

This book addresses supergravity and supergravity-motivated effective field theories in the context of cosmological model building. Extracting information about quintessence from string theory has attracted much attention in the past few years.  The question became more urgent very recently after the possibility of obtaining de Sitter space was called into question. Therefore, there is an interesting debate as to whether de Sitter space or, even, quintessence can be derived from a fundamental theory, string theory or otherwise. This is a very active field of research, and the topics covered...

Supersymmetry (SUSY) introduces superpartners of the Standard Model (SM) particles. If their masses are typically O(100 GeV) ∼ O(TeV), a lightest neutralino can be a candidate for the dark matter, and the problem is solved by canceling the correction of the Higgs boson mass. Further, SUSY can explain the experimental result of the muon magnetic moment (g-2).This book presents a search for electroweakinos—the superpartners of the SM electroweak bosons—such as charginos and neutralinos using data at the LHC collected by the ATLAS detector. Pair-produced electroweakinos decay into the...

The thesis gives the first experimental demonstration of a new quantum bit (“qubit”) that fuses two promising physical implementations for the storage and manipulation of quantum information – the electromagnetic modes of superconducting circuits, and the spins of electrons trapped in semiconductor quantum dots – and has the potential to inherit beneficial aspects of both. This new qubit consists of the spin of an individual superconducting quasiparticle trapped in a Josephson junction made from a semiconductor nanowire. Due to spin-orbit coupling in the nanowire, the supercurrent...

This thesis addresses the problem of improving the alignment of carbon nanotubes (CNTs) in transistor applications, taking a unique approach using iptycenes acting as molecular tweezers in combination with a liquid crystal solvent. As part of a project to test the effectiveness of a multi-step method, the so-calledAlignmentRelayTechnique (ART), this work contributed evidence for the selectivity and stability of ART, as well as providing the first proof-of-concept that ART can be used to create CNT field-effect transistors (FETs). The thesis effectively explains and illustrates the chemical...

This thesis focuses on the exploration of nontrivial spin dynamics in graphene-based devices and topological materials, using realistic theoretical models and state-of-the-art quantum transport methodologies. The main outcomes of this work are: (i) the analysis of the crossover from diffusive to ballistic spin transport regimes in ultraclean graphene nonlocal devices, and (ii) investigation of spin transport and spin dynamics phenomena (such as the (quantum) spin Hall effect) in novel topological materials, such as monolayer Weyl semimetals WeTe2and MoTe2. Indeed, the ballistic spin transport...

This thesis represents a breakthrough in our understanding of the noise processes in Microwave Kinetic Inductance Detectors (MKIDs). While the detection of ultraviolet to near-infrared light is useful for a variety of applications from dark matter searches to biological imaging and astronomy, the performance of these detectors often limits the achievable science. The author’s work explains the limits on spectral resolution broadening, and uses this knowledge to more than double the world record spectral resolution for an MKID suitable for optical and near-IR astrophysics, with emphasis on...

The thesis tackles two distinct problems of great interest in gravitational mechanics — one relativistic and one Newtonian. The relativistic one is concerned with the "first law of binary mechanics", a remarkably simple variational relation that plays a crucial role in the modern understanding of the gravitational two-body problem, thereby contributing to the effort to detect gravitational-wave signals from binary systems of black holes and neutron stars. The work reported in the thesis provides a mathematically elegant extension of previous results to compact objects that carry spin...

The nuclear shell model has had much success when describing nuclear structure. It is able to describe the single-particle states of nuclei, and gives understanding as to how nuclear structure evolves as the number of nucleons changes in a nucleus. This led to the discovery of the so-called magic numbers, which designate particularly stable configurations of protons and neutrons in nuclei.With the advent of radioactive ion beams, it has become possible to probe exotic nuclei to test current theories of nuclear structure. These investigations have led to the discovery of exotic nuclear...