2024 Projects

UW Physics REU 2024 Project List


Projects are offered from the following physics subfields:

Additional projects may be added to this list. If you have a special interest not represented in the list below, feel free to contact either Gray Rybka or Arthur Barnard for help.  They may be able to design new projects that align with your interests.


Experimental Projects


Developing the next generation of rare pion decay experiment

Quentin Buat


The electron is the first elementary particle ever discovered and is arguably the most studied particle so far. It holds a unique place in science as it plays a key role in numerous physical phenomena from electricity to chemistry. In the Standard Model of Particle Physics, the muon is a copy of the electron: a different version of the same particle in a different flavour, governed by the same interaction rules. This fundamental principle, known as Lepton Flavour Universality, is a centerpiece of the Standard Model of Particle Physics—yet recent measurements from the LHCb and muon g-2 experiments indicate that it might be violated. 


The PIONEER experiment (https://arxiv.org/pdf/2203.01981.pdf) aims at measuring the charged-pion branching ratio to electrons vs muons. This quantity is known in the SM with a precision of 1 part in 1e4, which is 15 times more precise than the current experimental result. Improving the experimental sensitivity would constitute a stringent test of Lepton Flavour Universality, probing mass scales up to the PeV range.


In order to achieve the needed precision, the PIONEER experiment, based on experience gathered by the PIENU (https://arxiv.org/abs/1506.05845) and PEN (https://arxiv.org/pdf/1407.2865.pdf) experiments, will need to have an excellent timing and energy resolution, high-speed detector and electronic response and a complete event reconstruction.


The selected candidate will work on developing several aspects of the experiment, from cutting-edge algorithms for the event reconstruction to lab tests of key components of the detector.



Searching for boosted Higgs bosons in the di-tau final state

Quentin Buat


Since the discovery of the Higgs boson in 2012, ATLAS and CMS have performed a series of measurements to explore its interactions with the SM particles with more and more precision. With the wealth of data collected, Higgs bosons are now being produced copiously and we can start to explore more extreme phase-spaces. New heavy particles predicted beyond the energy reach of the LHC could still manifest themselves in the ATLAS dataset through quantum corrections. Higgs boson events produced with a very high momentum transfer from the incoming partons represent a great opportunity to look for such particles. However the decay products of the Higgs boson tend to be extremely collimated in these events and require dedicated techniques to detect them. 


ATLAS recently published a new measurement of the Higgs boson cross-sections in the di-tau final state [1]. This measurement is however limited at high Higgs boson transverse momentum by the experimental techniques employed to detect tau leptons. 


In this project, you will explore an alternate reconstruction technique [2] and design a new analysis strategy to enhance the sensitivity of the ATLAS experiment to these types of events.



Quantum Computing with Trapped Ions

Boris Blinov


In the trapped ion quantum computing lab at the University of Washington we experimentally investigate the techniques for building a conceptually new type of computational device. A quantum computer will be extremely fast at solving some important computational problems, such as the factoring and the database search. While days of practical quantum computing may be quite far in the future, we are developing the main building blocks of such a device – the quantum bits ("qubits"), the basic logic operations, the qubit readout... The physical implementation of the qubit in our lab is the hyperfine spin of a single, trapped barium ion. A student in this REU project will participate in experiments with laser-cooled, RF-trapped single ions, will help develop techniques for single- and multi-qubit manipulation via microwave-induced hyperfine transitions and ultrafast laser-driven excitations. They will gain valuable hands-on experience with lasers and optics, RF and digital electronics, and ultrahigh vacuum technology.



The Search for Dark Matter with DAMIC-M

Alvaro Chavarria


DAMIC-M will consist of an array of large-area, thick charge-coupled devices (CCDs) capable of detecting extremely small energy depositions that ionize as little as two electron-hole pairs in the silicon target. This detector will provide unprecedented sensitivity to low-mass dark matter particle candidates in the galactic halo that may interact with ordinary atoms in the target. The DAMIC-M detector will be constructed throughout 2023. The goal of this REU project is to perform a realistic estimate of the sensitivity of DAMIC-M through a series of experimental measurements and numerical simulations.



Advanced two-dimensional devices

David Cobden


In our group we investigate new physics in devices made from combinations of two-dimensional van der Waals materials, including graphene and many others. Phenomena under study include 2D topological phases, 2D superconductivity, 2D ferroelectricity, 2D magnetism and 2D phase transitions. In this project the student will learn to make their own 2D devices with a particular physics goal in mind, and then carry out a range of measurements, which are likely to include low temperature transport in high magnetic fields and suitable kinds of photoexcitation and spectroscopy.



Formation of defect qubits in crystals

Kai-Mei Fu


The Quantum Defect Lab researches the synthesis, properties and control of single defects in crystals that can be used as qubits in quantum information applications. The REU student will explore defect creation via implantation and annealing experiments. 



Quantum Simulation and Sensing with Ultracold Atoms

Subhadeep Gupta


Ultracold and trapped atoms can be precisely initialized, controlled, and detected, forming a pristine experimental platform for quantum simulation of complex many-body problems. In our lab we trap and cool atoms with laser fields to microKelvin temperatures and then control their interactions and evolution using additional lasers and magnetic fields. One possible REU project involves working on frequency control of laser setups to apply tunneling and local potential terms in quantum transport Hamiltonians. The associated hardware that the student will work with include acousto-optic modulators for laser beams, arbitrary waveform generator (AWG), and radiofrequency electronics. Another possible REU project involves programming an AWG to produce an array of laser beams for tweezer trapping of an array of single atoms for quantum simulation and information processing. The student would be involved in both the design and testing of such arrays. A third possible project is to work on optical lattice optimization for enhanced quantum sensing using atom interferometry. 



Improving Nanopore Sequencing

Andrew Laszlo


Our group develops nanotechnology for DNA and protein sequencing using nanopores (~1nm holes within thin membranes). A DNA or peptide strand can be threaded through a nanopore and the individual DNA bases or amino acids can be read off as they pass through the pore. Our work is highly multidisciplinary, involving physics, microbiology, enzymology, statistics, and signal processing. This upcoming summer we will have projects available in instrumentation and data analysis depending on the student's background and interest. 



Radiofrequency Detectors for Particle Physics

Gray Rybka


Advances in ultra low noise microwave electronics have opened the door to a new generation of detectors with extreme sensitivity to very low energy signals. This project will be related to developing detectors that have applications to astroparticle physics: axion dark matter and neutrino mass measurements.



Search for Dark Matter

Gray Rybka


Our group is operating the Axion Dark Matter eXperiment (ADMX), a detector to search for the axion, a hypothetical particle that may form the dark matter in our galaxy. We recently commissioned a new data channel that looks for axions that have recently fallen into our galactic dark-matter halo. Also, we're in the process of rebuilding the detector for its high-sensitiity scan. We welcome someone with computing and mechanical skills who can join our group and who has an interest in experimental cosmology.



2D Semiconductor Moiré Quantum Simulator

Xiaodong Xu


Many-body interactions between carriers lie at the heart of condensed matter physics. The ability to tune such interactions would open the possibility to access and control complex electronic phase diagrams on demand. Recently, moiré superlattices formed by two-dimensional materials have emerged as a promising platform for simulating quantum many-body Hamiltonian. In this project, the students will have the opportunity to learn this topic by participating in the 2D moiré superlattice fabrication (van der Waals crystal exfoliation, layer transfer, atomic force microscopy imaging, electron beam lithography) and characterization via a suite of optical techniques (e.g. photoluminescence, optical reflection, magneto-optical spectroscopy). 



Quantum electronics in two dimensions 

Matthew Yankowitz


A wide family of van der Waals (vdW) materials can be mechanically isolated down to atomic monolayer thickness. These crystals can further be mixed-and-matched and stacked on top of one another to create heterostructures with designer electronic properties. When two neighboring crystals are rotated, a geometric superlattice moiré pattern emerges which further modifies the overall device properties. The REU student will learn how to fabricate devices consisting of 2D vdW materials. Using electrical transport measurements, the student will be involved in the characterization of devices exhibiting novel tunable electronic phenomena including superconductivity, magnetism, and other effects of electronic correlations.



Theory/Numerical Modeling Projects


Nuclear and Neutrino Astrophysics

Vincenzo Cirigliano and Sanjay Reddy


We invite students interested in nuclear and neutrino astrophysics to join the Institute for Nuclear Theory for a summer research experience that will involve both lectures and individual research projects.  The first two weeks of this program will include lectures by Profs. Cirigliano and Reddy, covering key areas of nuclear and neutrino astrophysics.  The student(s) would then work on specific projects. Collaboration and discussion with other students and members of the INT will be encouraged.  The research projects are described below. 



Neutron stars, dense matter, and gravitational waves

Vincenzo Cirigliano and Sanjay Reddy


During the past decade, the detection of gravitational waves from neutron stars and black holes ushered in a new era of multi-messenger astrophysics and astronomy. It is now possible to study neutron stars, their interiors, and their dynamics by combining information from multiple messengers, electromagnetic waves (radio, optical, x-ray, and gamma-rays), neutrinos, and gravitational waves. Advances in theory and computer simulations have begun to elucidate the unique role of neutron stars in our universe.  We now appreciate that they could help us address longstanding questions in fundamental physics ranging from the nature of matter at an extreme density where quarks are likely to manifest in novel configurations to the origin of heavy elements such as gold, platinum, and uranium.      


The REU project is designed to provide the student with an overview of neutron star astrophysics and the physics of matter at extreme density. It will include writing computer programs to calculate the pressure of strongly interacting quantum matter at high density and finding solutions to the general relativistic equations of hydrostatic equilibrium that govern the structure of non-rotating and slowly-rotating compact objects. 



Neutrinos in astrophysics  

Vincenzo Cirigliano and Sanjay Reddy


Neutrinos are perhaps the most mysterious and elusive of the known particles, because they  interact very weakly and have tiny masses,  the heaviest neutrino being at least a million times lighter than the lightest charged particle.   Yet, they play a crucial role in the early universe and the evolution of stars,  as in these environments neutrinos  are copiously produced and  transport most of the energy and entropy.   Moreover, observations of solar, atmospheric, reactor, and accelerator neutrinos indicate  that a neutrino produced in a given flavor state (electron, muon, or tau)  can morph to another flavor state as it evolves,  through a quantum mechanical interference effect.  In turn, these so-called neutrino oscillations can have a big impact on the  neutron-to-proton ratio, a key quantity in determining what elements are synthesized in the early universe and the ejecta surrounding supernovae and neutron star mergers.  


The REU student will learn how neutrinos evolve in a hot and dense astrophysical medium and will perform numerical studies of neutrino evolution in various astrophysical settings, of increasing complexity. The first step will involve studying neutrino evolution in the sun.  The student will then explore generalizations relevant  to other astrophysical objects, such as supernovae, including in the simulation more and more realistic microphysics.  



Quantum Simulation with Interacting Photons

Arka Majumdar


Understanding correlated many-body effects, including high-temperature superconductivity and fractional quantum Hall physics is not only of fundamental scientific interest but also has the potential for transformational societal impact, with applications in faster, more efficient electronics and topological quantum computers. However, such systems are extremely difficult to study theoretically due to the massive computational resources required. An innovative solution is to build an alternative, well-controlled experimental platform to simulate the performance of these correlated electronic systems. Several physical systems, including cold atoms, ion traps, defect centers, and superconducting circuits, have been considered for quantum simulations. In particular, strongly interacting optical photons provide a unique approach to non-equilibrium many-body quantum simulation due to the ease of adding and destroying photons via external driving and photon loss, as well as measuring multi-photon correlations using readily available single photon detectors. Such interactions, however, require the realization and control of nonlinear optics (NLO) at the few photon level, a daunting task in practice. We have recently developed a platform using solution processed quantum dots coupled to an array of cavities. Unfortunately, in this platform, we cannot reach single photon nonlinearity easily. In the REU project, we plan to model this quantum system (using master equation and quantum trajectory method) and identify the steady-state observables, which exhibit quantum mechanical behavior, even in the absence of single photon nonlinearity. The project also aims to understand the use of this nonlinear coupled cavity array to problems such as quantum machine learning.



Light Front Quantum Mechanics

Gerald Miller


In 1947 Dirac introduced a new form of relativistic quantum mechanics in which the variable ct +z acts as a “time” coordinate and ct-z acts as a “space” coordinate. This so-called light front formalism was largely forgotten until the 1970's, when it turned out to be useful in analyzing a variety of high energy experiments. Despite the phenomenological success of this formalism, it has enjoyed only limited use in computing wave functions of particles and atomic nuclei. The present project is devoted to using the light front formalism to solve quantum mechanics problems involving bound and scattering states. A mathematically strong REU student would learn about relativistic quantum mechanics through the process of solving the relevant relativistic equations. This project would involve working on interesting and timely topics, including the role of entanglement,  and could provide great preparation for graduate school quantum mechanics, field theory or even string theory. A full year of quantum mechanics is a necessary prerequisite. 



Learning the shape of protein universe

Armita Nourmohammad


Proteins play a central role in all parts of biology from immune recognition to brain activity. A key challenge is to predict how protein sequence and structure determines function, such as the protein’s binding affinity to ligands or its enzymatic activity. With the growth of molecular data, machine learning has become a powerful tool in protein science. However, these techniques often generate black-box models, which are powerful but hard to interpret. In this project, students work to develop AI-guided approaches to protein structure-function maps, which respect the physical symmetries in the representation of proteins, and hence, result in more interpretable models of protein micro-environments that could reflect the underlying biophysics.


This project will allow students to work with protein sequence and structural data as well as implementing basic statistical methods for machine learning in Python. This project is computationally intensive and students will learn to work with high performance computing (HPC) to analyze and interpret large data. Background in biology is not necessary but students should have a strong background in statistical mechanics and should be familiar with programming languages such as Python, Julia, or others.



Information processing and control of evolving populations

Armita Nourmohammad


Adaptive Darwinian evolution is an act of information processing: populations sense and measure the state of their environment and adapt by changing their configurations accordingly. Changes of the environment result in an irreversible out-of-equilibrium adaptive evolution, with a constant flow of information. In this project students will explore the fundamental limits in evolution and ecology by combining theoretical approaches grounded in statistical physics and information theory with molecular data. In particular, we aim to develop adaptive optimal control approaches for artificial selection to drive evolving populations towards desired phenotypic targets. The efficacy of such control approaches is limited by our ability to predict evolution — a theoretical limit that we will closely study in this project.


To tackle this problem, students will develop stochastic models for the evolutionary process and apply numerical and analytical techniques to study the underlying dynamics. Background in biology is not necessary but students should have a strong background in statistical mechanics and should be familiar with programming languages such as Python, Julia, or others.



Functional organization of the adaptive immune system

Armita Nourmohammad


The adaptive immune system consists of highly diverse B- and T-cell receptors, which can recognize and specifically react to a multitude of diverse pathogens. Over the past decade, there has been a growth of sequence data on immune receptors, along with more limited information on their interactions with pathogens. Statistical inference and AI-guided approaches to interpret these high-throughput immune repertoire sequences has shed light on the generation of immune receptor diversity and how biophysical features of immune receptors are selected for different function. The goal of this project is to construct data-driven approaches to infer sequence determinants of function for B-cell receptors, as they differentiate to perform distinct functions within an individual.


This project will allow students to work with high-throughput immune receptor repertoire data and will familiarize them with statistical modeling and inverse-inference techniques. This project is computationally intensive and students will learn to work with high performance computing (HPC) to analyze and interpret large data. Background in biology is not necessary but students should have a strong background in statistical mechanics and should be familiar with programming languages such as Python, Julia, or others.



Characterization, analysis, and prototyping for LEGEND

Jason Detwiler


The Large Enriched Germanium Experiment for Neutrinoless ββ Decay (LEGEND, https://legend-exp.org/) is an international collaboration using high-purity germanium detectors to search for neutrinoless double beta-decay. This hypothesized type of beta-decay would provide unambiguous evidence for lepton number non-conservation and identify neutrinos as Majorana particles. By deploying novel-geometry germanium detectors inside of a liquid argon cryostat, LEGEND achieves high energy resolution and pulse shape discrimination from the germanium detectors while vetoing background events that deposit energy in the liquid argon scintillator. The current LEGEND-200 and future LEGEND-1000 experiments will probe neutrinoless double beta-decay lifetimes from current limits near 10^26 years to beyond 10^28 years.


There are several possible projects (or a combination of them) with LEGEND depending on student interest:


1) LEGEND-200 is currently taking science data, which requires development of new analysis techniques and routines. The student will have the opportunity to learn about digital signal processing, investigate and develop new filtering routines, and contribute to the science analysis of the experiment. Analysis is performed in Python.

 

2) In order to understand the detector response to particular backgrounds, characterization of detectors is essential. At UW, characterization test stands are used to investigate detector response to near-surface interactions of photons and charged particles. In this project, the student will help develop and test an x-ray fluorescence source for use in these test stands that will allow for investigation of the low-energy response of the detectors and characterize the active volume of the detectors.

 

3) LEGEND-1000, the next generation experiment, is currently under design with a possible start date in a few years. As part of this experiment, a specialized device to insert strings of detectors into the liquid argon cryostat without exposing the cryogen to air is required. This device is being designed and prototyped at UW, and the student will significantly contribute to the prototyping effort while learning about vacuum, gas handling, and mechanical systems.

 

4) Finally, the digital signal processing routines developed by the LEGEND collaboration for germanium detectors can also be applied to silicon detectors. In this project, the student will aid in design, data-taking, and analysis of a small experiment with a silicon detector to investigate whether digital signal processing routines can be used to perform particle discrimination between alpha and beta particles.