Degree Date: December, 2015
Faustin Carter's picture
Faustin Carter
Daniel Prober

HRL Laboratories

A transition-edge-sensor-based instrument for the measurement of individual He2* excimers in a superfluid 4He bath at 100 mK
This dissertation is an account of the first calorimetric detection of individual He2* excimers within a bath of superfluid 4He. When superfluid helium is subject to ionizing radiation, diatomic He molecules are created in both the singlet and triplet states. The singlet He2* molecules decay within nanoseconds, but due to a forbidden spin-flip the triplet molecules have a relatively long lifetime of 13 seconds in superfluid He. When He2* molecules decay, they emit a ~15 eV photon. Nearly all... more
Nathan Cooper's picture
Nathan Cooper
Volker Werner

Structure of A = 76 Nuclei and Fast-Timing Studies of the Rare-Earth Region
Photon strength of nuclei has been a topic of recent intrigue due to postulated exotic modes of excitation, such as a neutron skin resonance, as well as the difficulty of its measurement near the neutron separation energy. The large number of levels up to the neutron separation energy, a region of particular interest in the calculation of nuclear reaction probabilities, causes detailed and accurate measurements to be close to the threshold of current experimental limits. This talk will begin... more
Daniel Guest's picture
Daniel Guest
Paul Tipton/Tobias Golling

A Search for Scalar Charm Quarks with the ATLAS Detector at the LHC
This thesis presents the results of a search for pair-produced scalar charm quarks with the ATLAS detector at the LHC. The search uses 20.3 fb^-1 of data collected during the sqrt(s) = 8 TeV 2012 run. Each charm quark decays to neutrilinos and charm quarks, resulting in a final state consisting of two charm jets and missing transverse energy. A novel `charm tagging' algorithm was developed to separate this signature from backgrounds, and is discussed in detail. As no evidence of physics... more
Eric Holland's picture
Eric Holland
Robert Schoelkopf
Staff Scientist

Lawrence Livermore National Laboratory

Cavity State Reservoir Engineering in Circuit Quantum Electrodynamics
Engineered quantum systems are poised to revolutionize information science in the near future. A persistent challenge in applied quantum technology is creating controllable, quantum interactions while preventing information loss to the environment, decoherence. In this thesis, we realize mesoscopic superconducting circuits whose macroscopic collective degrees of freedom, such as voltages and currents, behave quantum mechanically. We couple these mesoscopic devices to microwave cavities forming... more
Emma Ideal's picture
Emma Ideal
Sarah Demers
Research Scientist, Core Data Science


A Search for the Standard Model Higgs Boson Produced in Association with a Vector Boson and Decaying to a Hadronically-Decaying Tau Pair at ATLAS
On July 4, 2012, the discovery of the Higgs boson was simultaneously announced by the ATLAS and CMS collaborations. Since then, evidence for its decay to tau leptons has been claimed. As of now, there have been no Higgs discoveries in any of its associated production modes. For this thesis, a search for the Higgs boson produced in association with a vector boson V = W^(+-), Z and decaying to a tau lepton pair was conducted using 2012 ATLAS data. The data corresponds to 20.3 fb^(-1) of 8 TeV... more
Peter Koo's picture
Peter Koo
Simon Mochrie

Novel optical-based methods and analyses for elucidating cellular mechanics and dynamics
Resolving distinct biochemical interaction states by analyzing the diffusive behaviors of individual protein trajectories is challenging due to the limited statistics provided by short trajectories and experimental noise sources, which are intimately coupled into each protein’s localization. In the first part of this thesis defense, I will describe a novel, machine-learning based classification methodology, called perturbation expectation-maximization (pEM), which simultaneously analyzes... more
Daliang Li's picture
Daliang Li
Witold Skiba
Postdoctoral Associate

Harvard University

Covariant Methods for Superconformal Field Theories
In this thesis, we develop manifestly covariant methods for 4 dimensional, N = 1 superconformal field theories. First, we generalize the embedding formalism in conformal field theories (CFTs) to N = 1 superconformal field theories (SCFTs). As applications we construct manifestly superconformally covariant expressions for 2- and 3-point correlation functions involving the supercurrent multiplet or the global symmetry current superfield. Next, we combine this superembedding formalism with the... more
Tudor Petrescu's picture
Tudor Petrescu
Karyn Le Hur

Topological phases with ultracold atoms and photons
In the first part of the talk, we introduce two–dimensional lattice tight–binding models that realize the quantum anomalous Hall effect (QAHE). For a Kagome lattice whose degrees of freedom are photons in microwave resonators, we discuss protocols to access the local Berry curvature and the Chern number of Bloch bands from the semiclassical dynamics of wavepackets. We proceed to Haldane’s model for QAHE on the honeycomb lattice, but with repulsively interacting bosons at unit... more
Brian Vlastakis's picture
Brian Vlastakis
Robert Schoelkopf

Controlling coherent state superpositions with superconducting circuits
Quantum computation requires a large yet controllable Hilbert space. While many implementations use discrete quantum variables such as the energy states of a two-level system to encode quantum information, continuous variables could allow access to a larger computational space while minimizing the amount of required hardware. With a toolset of conditional qubit-photon logic, we encode quantum information into the amplitude and phase of coherent state superpositions in a resonator, also known as... more
Degree Date: May, 2015
Tomas Aronsson's picture
Tomas Aronsson
John Harris

Cross section of bottom electrons in proton-proton collisions in the ALICE experiment
High-energy heavy-ion collisions at the LHC allow for the study of the properties of the quark-gluon plasma (QGP). Heavy quarks, charm and bottom, produced in the initial hard scattering processes of the collision are excellent probes of the QGP. When heavy quarks traverse the QGP they are expected to lose energy and such energy loss is predicted to be smaller than for gluons and light quarks. On the other hand, recent experimental data indicate larger energy loss than expected. Heavy flavor... more
Hongchul Joseph Bae's picture
Hongchul Joseph Bae
Vincent Moncrief
Pricing Quant


Wormhole Solutions to the Bianchi IX Wheeler-DeWitt Equation using the Euclidean-signature Semi-classical Method
A Euclidean-signature semi-classical method is used to construct both ground and excited state solutions to the canonically quantized Bianchi IX (Mixmaster) cosmological models. Employing a modified form of the semi-classical ansatz, we solve the relevant Wheeler-DeWitt equation asymptotically by integrating a set of linear transport equations along the flow of a suitably chosen solution to the corresponding Euclidean-signature Hamilton-Jacobi equation. For the Moncrief-Ryan (or ‘wormhole... more
Alexander Cerjan's picture
Alexander Cerjan
A. Douglas Stone

Penn State University

Fundamental physics and device design using the steady-state ab initio laser theory
In this thesis we generalize and extend the steady-state ab initio laser theory (SALT), first developed by Tureci and Stone, and apply it problems in laser design. SALT as first formulated modeled the gain medium as identical two-level atoms, leading to the well-known Maxwell Bloch laser equations. The result is a set of coupled non-linear wave equations that treats the openness of the cavity exactly and the non-linear modal interactions to infinite order. Most gain media have more than two... more
Andrew Leister's picture
Andrew Leister
Sarah Demers
Data Scientist Senior

Freddie Mac

A Search for Z' Gauge Bosons Decaying to Tau-Antitau Pairs in Proton-Proton Collisions with the ATLAS Detector
Although the Standard Model of Particle Physics has been generally successful in modeling fundamental particles and their interactions, it does not incorporate many observed physical phenomena. Many theoretical models attempting to explain physics beyond the Standard Model have been developed, several of which include one or more additional neutral gauge bosons, or Z'. The potential mass range of a Z' is quite large and for some models includes Z' masses at the TeV scale. A search... more
Christopher McKitterick's picture
Christopher McKitterick
Daniel Prober
Engagement Manager

McKinsey and Company

Prospects for Ultra-sensitive Terahertz Photon Detection with Graphene
This dissertation investigates a new scheme for the detection of terahertz (THz) photons. The vast majority of photons visible to outer space observatories occur in the far-infrared, but there do not yet exist detectors sensitive enough to accurately measure the faintest signals. I propose to use graphene, a single atomic layer of graphite, as the detecting element to observe these weak sources. As a result of its nano-scale dimensions, there are few charge carriers in graphene systems per unit... more
Xiaoxiao Wang's picture
Xiaoxiao Wang
Tobias Golling

Search for a supersymmetric partner of the top quark using boosted top quark identification with the ATLAS detector
The Higgs discovery at the LHC has brought new attention to the hierarchy problem and the theory of Supersymmetry (SUSY). The supersymmetric partner of the top quark - the top squark (stop), is of paramount importance as it contributes the largest higher-order radiative corrections to the Higgs squared-mass. Naturalness arguments favor a light stop, making it a good candidate for discovery at the LHC. A search of the stop pair production in final states with one isolated lepton, jets, and... more