J. Watkins
A5049387606- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Quantum Computing Algorithms and Architecture
- Radiation Detection and Scintillator Technologies
- Quantum Information and Cryptography
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Astrophysics and Cosmic Phenomena
- Nuclear physics research studies
- Low-power high-performance VLSI design
- Quantum many-body systems
- Nuclear Physics and Applications
- Quantum and electron transport phenomena
- Atomic and Molecular Physics
- Quantum chaos and dynamical systems
- Quantum, superfluid, helium dynamics
- VLSI and FPGA Design Techniques
- Atmospheric Ozone and Climate
- Quantum-Dot Cellular Automata
- Astronomical and nuclear sciences
- CCD and CMOS Imaging Sensors
- Dietary Effects on Health
- Numerical Methods and Algorithms
- Genetics, Aging, and Longevity in Model Organisms
Michigan State University
2019-2024
Carleton University
2018-2023
The Ohio State University
2023
Baker Engineering (United States)
2021
National Superconducting Cyclotron Laboratory
2019-2020
Institute for Physics
2019
University of Massachusetts Amherst
2019
Stanford University
2013
A search for neutrinoless double-beta decay ($0\nu\beta\beta$) in $^{136}$Xe is performed with the full EXO-200 dataset using a deep neural network to discriminate between $0\nu\beta\beta$ and background events. Relative previous analyses, signal detection efficiency has been raised from 80.8% 96.4$\pm$3.0% energy resolution of detector at Q-value improved $\sigma/E=1.23\%$ $1.15\pm0.02\%$ upgraded detector. Accounting new data, median 90% confidence level half-life sensitivity this analysis...
The projected performance and detector configuration of nEXO are described in this pre-Conceptual Design Report (pCDR). is a tonne-scale neutrinoless double beta ($0νββ$) decay search $^{136}$Xe, based on the ultra-low background liquid xenon technology validated by EXO-200. With $\simeq$ 5000 kg enriched to 90% isotope 136, has half-life sensitivity approximately $10^{28}$ years. This represents an improvement about two orders magnitude with respect current results. Based experience gained...
We present a stochastic quantum computing algorithm that can prepare any eigenvector of Hamiltonian within selected energy interval $[E-\epsilon, E+\epsilon]$. In order to reduce the spectral weight all other eigenvectors by suppression factor $\delta$, required computational effort scales as $O[|\log \delta|/(p \epsilon)]$, where $p$ is squared overlap initial state with target eigenvector. The method, which we call rodeo algorithm, uses auxiliary qubits control time evolution minus some...
Quantum metrology allows for measuring properties of a quantum system at the optimal Heisenberg limit. However, when relevant states are prepared using digital Hamiltonian simulation, accrued algorithmic errors will cause deviations from this fundamental In work, we show how due to Trotterized time evolution can be mitigated through use standard polynomial interpolation techniques. Our approach is extrapolate zero Trotter step size, akin zero-noise extrapolation techniques mitigating...
We apply deep neural networks (DNN) to data from the EXO-200 experiment. In studied cases, DNN is able reconstruct relevant parameters—total energy and position—directly raw digitized waveforms, with minimal exceptions. For first time, developed algorithms are evaluated on real detector calibration data. The accuracy of reconstruction either reaches or exceeds what was achieved by conventional approaches over course Most existing event classification in particle physics trained Monte Carlo...
This paper presents techniques for designing nanoelectromechanical relay-based logic circuits using six-terminal relays that behave as universal gates. With proper biasing, a compact 2-to-1 multiplexer can be implemented single relay. Arbitrary combinational functions then well-known binary decision diagram (BDD) techniques. Compared to CMOS-style implementation four-terminal relays, the BDD-based result in lower area without major impact on performance metrics such delay, and energy (when...
Liquid xenon (LXe) is employed in a number of current and future detectors for rare event searches. We use the EXO-200 experimental data to measure absolute scintillation ionization yields generated by $\ensuremath{\gamma}$ interactions from $^{228}\mathrm{Th}$ (2615 keV), $^{226}\mathrm{Ra}$ (1764 $^{60}\mathrm{Co}$ (1332 keV 1173 keV) calibration sources, over range electric fields. The $W$ value that defines recombination-independent energy scale measured be...
Charge radii of the unstable Ca36 and Ca38 nuclei were recently determined used to compute differences in charge between mirror ΔRch for Ca36−S36 Ca38−Ar38 pairs. Given correlation slope symmetry energy L at nuclear saturation density, we deduce L=5–70 MeV, which rules out a large fraction models that predict "stiff" equation state. This is most precise determination this model based on electromagnetic probes ground states. The range consistent with earlier analyses from both laboratory...
In the current era of noisy quantum devices, there is a need for algorithms that are efficient and robust against noise. Towards this end, we introduce projected cooling algorithm computation. The able to construct localized ground state any Hamiltonian with translationally-invariant kinetic energy interactions vanish at large distances. term "localized" refers localization in position space. method can be viewed as analog evaporative cooling. We start an initial support over compact region...
We present a search for electron-recoil signatures from the charged-current absorption of fermionic dark matter using EXO-200 detector. report an average background rate $6.8\ifmmode\times\else\texttimes\fi{}{10}^{4}\text{ }\text{ }\mathrm{cts}\text{ }{\mathrm{kg}}^{\ensuremath{-}1}\text{ }{\mathrm{yr}}^{\ensuremath{-}1}\text{ }{\mathrm{keV}}^{\ensuremath{-}1}$ above 4 MeV and find no statistically significant excess over our projection. Using total $^{136}\mathrm{Xe}$ exposure 234.1 kg yr,...
A search for Majoron-emitting modes of the neutrinoless double-beta decay $^{136}$Xe is performed with full EXO-200 dataset. This dataset consists a total exposure 234.1 kg$\cdot$yr, and includes data detector upgrades that have improved energy threshold relative to previous searches. lower limit T$_{1/2}^{\rm{^{136}Xe}}>$4.3$\cdot$10$^{24}$ yr at 90\% C.L. on half-life spectral index $n=1$ Majoron was obtained, factor 3.6 more stringent than from EXO-200, corresponding constraint...
The hyperfine coupling constants of neutron deficient $^{37}\mathrm{Ca}$ were deduced from the atomic spectrum $4s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}\phantom{\rule{0.16em}{0ex}}\ensuremath{\leftrightarrow}\phantom{\rule{0.16em}{0ex}}4p\phantom{\rule{0.16em}{0ex}}^{2}P_{3/2}$ transition in Ca ii, measured using collinear laser spectroscopy technique. ground-state magnetic-dipole and spectroscopic electric-quadrupole moments determined for first time as...
Context: The New York City (NYC) Test & Trace Corps (Test Trace), under Health + Hospitals (NYC H+H), set out to provide universal access COVID-19 testing. partnered with numerous organizations direct mobile testing from concept through implementation reduce COVID-19-related health inequities. Program: employs a community-informed model deliver the hardest-hit, underserved communities. Community partners, uniquely knowledgeable of residents they serve, are engaged as decision makers and...
Compared with time independent Hamiltonians, the dynamics of generic quantum Hamiltonians $H(t)$ are complicated by presence ordering in evolution operator. In context digital simulation, this difficulty prevents a direct adaptation simulation algorithms for dependent simulation. However, there exists framework within theory dynamical systems which eliminates adding "clock" degree freedom. work, we provide computational framework, based on reduction, encoding as systems. As result, make two...
Compared with time-independent Hamiltonians, the dynamics of generic quantum Hamiltonians <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><a:mi>H</a:mi><a:mo stretchy="false">(</a:mo><a:mi>t</a:mi><a:mo stretchy="false">)</a:mo></a:math> are complicated by presence time ordering in evolution operator. In context digital simulation, this difficulty prevents a direct adaptation many simulation algorithms for time-dependent simulation. However, there...
Generative Adversarial Networks trained on samples of simulated or actual events have been proposed as a way generating large datasets at reduced computational cost. In this work, novel approach to perform the simulation photodetector signals from time projection chamber EXO-200 experiment is demonstrated. The method based Wasserstein Network - deep learning technique allowing for implicit non-parametric estimation population distribution given set objects. Our network real calibration data...
We show that a one-dimensional chain of trapped ions can be engineered to produce quantum mechanical system with discrete scale invariance and fractal-like time dependence. By we mean replicates itself under rescaling distance for some factor, fractal is signal invariant the time. These features are reminiscent Efimov effect, which has been predicted observed in bound states three-body systems. demonstrate ion controlled two independently tunable parameters. also discuss extension $n$-body...
We report on a comparison between the theoretically predicted and experimentally measured spectra of first-forbidden nonunique β-decay transition 137Xe(7/2−)→137Cs(7/2+). The experimental data were acquired by EXO-200 experiment during deployment an AmBe neutron source. ultralow background environment EXO-200, together with dedicated source analysis procedures, allowed for collection pure sample decays, estimated signal to ratio more than 99 1 in energy range from 1075 4175 keV. In addition...
Product formulae are a popular class of digital quantum simulation algorithms due to their conceptual simplicity, low overhead, and performance which often exceeds theoretical expectations. Recently, Richardson extrapolation polynomial interpolation have been proposed mitigate the Trotter error incurred by use these formulae. This work provides an improved, rigorous analysis techniques for task calculating time-evolved expectation values. We demonstrate that, achieve $\epsilon$ in time $T$...
The rodeo algorithm is an efficient for eigenstate preparation and eigenvalue estimation any observable on a quantum computer. This makes it promising tool studying the spectrum structure of atomic nuclei as well other fields many-body physics. only requirement that initial state has sufficient overlap probability with desired eigenstate. While exponentially faster than well-known algorithms such phase adiabatic evolution preparation, yet to be implemented actual device. In this work, we...
We introduce a new scheme for quantum circuit design called controlled gate networks. Rather than trying to reduce the complexity of individual unitary operations, objective networks is toggle between all operations needed with fewest number gates. illustrate our approach using specific class networks, reversal gates, estimate eigenvalues two-qubit Hamiltonian via Rodeo Algorithm. A five-fold reduction in gates observed as compared an equivalent standard use Quantinuum H1-2 and IBM Perth...