Alumni
Faustin Carter Daniel Prober 
Physicist HRL Laboratories A transitionedgesensorbased 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 spinflip 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 Volker Werner 
Deceased Structure of A = 76 Nuclei and FastTiming Studies of the RareEarth 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 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 pairproduced 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 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 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 HadronicallyDecaying 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 Simon Mochrie 
Novel opticalbased 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, machinelearning based classification methodology, called perturbation expectationmaximization (pEM), which simultaneously analyzes... more 

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 3point correlation functions involving the supercurrent multiplet or the global symmetry current superfield. Next, we combine this superembedding formalism with the... more 

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 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 twolevel 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 qubitphoton logic, we encode quantum information into the amplitude and phase of coherent state superpositions in a resonator, also known as... more 
Tomas Aronsson John Harris 
Cross section of bottom electrons in protonproton collisions in the ALICE experiment Highenergy heavyion collisions at the LHC allow for the study of the properties of the quarkgluon 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 Vincent Moncrief 
Pricing Quant RBS Wormhole Solutions to the Bianchi IX WheelerDeWitt Equation using the Euclideansignature Semiclassical Method A Euclideansignature semiclassical 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 semiclassical ansatz, we solve the relevant WheelerDeWitt equation asymptotically by integrating a set of linear transport equations along the flow of a suitably chosen solution to the corresponding Euclideansignature HamiltonJacobi equation. For the MoncriefRyan (or ‘wormhole... more 

Alexander Cerjan A. Douglas Stone 
Postdoc Penn State University Fundamental physics and device design using the steadystate ab initio laser theory In this thesis we generalize and extend the steadystate 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 twolevel atoms, leading to the wellknown Maxwell Bloch laser equations. The result is a set of coupled nonlinear wave equations that treats the openness of the cavity exactly and the nonlinear modal interactions to infinite order. Most gain media have more than two... more 

Andrew Leister Sarah Demers 
Data Scientist Senior Freddie Mac A Search for Z' Gauge Bosons Decaying to TauAntitau Pairs in ProtonProton 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 Daniel Prober 
Engagement Manager McKinsey and Company Prospects for Ultrasensitive 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 farinfrared, 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 nanoscale dimensions, there are few charge carriers in graphene systems per unit... more 

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 higherorder radiative corrections to the Higgs squaredmass. 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 