Professor Thomas M. Crawford could host 1-3 undergraduate students in his laboratory
to work on nanotechnology projects related to the physics of magnetic nanoparticles
and quantum magnetic field sensing.
One undergraduate project applies AC magnetic fields to magnetic nanoparticles, using
a technique called Magnetic Particle Spectroscopy or MPS. By varying the AC frequency,
changes in how the nanoparticles “relax” each time the field is cycled can be measured
and correlated with the type of relaxation physics involved. For example, in Brownian
relaxation, the particle physically rotates to align with a local magnetic field,
which is in contrast to Néel relaxation, where the particle spins themselves rotate
internally with the field, independent of the physical orientation of the particle.
By varying the AC frequency to nanoparticles colloidally suspended in fluid, as well
as to particles immobilized on surfaces, the relative magnitude and transition between
such relaxation mechanisms can be mapped and understood as a function of nanoparticle
material properties. These dependencies are important for an improved understanding
the physics of relaxation in these materials, as well as for using them in important
applications from medicine to catalysis to sensing.
A second undergraduate project involves quantum-optical measurement of magnetic fields.
By optically-pumping defects implanted in single crystal diamond (called Nitrogen-Vacancy
or NV centers because when a Nitrogen displaces a Carbon it must include an empty
diamond lattice site adjacent to it), which act like a single spin, the resulting
photoluminescence can depend strongly on the applied magnetic field via the Zeeman
effect. This effect, called Optically Detected Magnetic Resonance or ODMR, allows
measurement of magnetic fields down to femtoTesla. Using a confocal microscope, groupings
of NV Centers can be imaged and used to detect local magnetic fields and/or nuclear
spins of magnetic nanoparticles, as well as other spin-active compounds such as PFAS
or combustion products. ODMR can thus enable highly-sensitive magnetometry as well
as NMR and ESR of single molecules.
A third undergraduate project involves nanomanufacturing diffractive optical elements
and using a combination of light sources to study spectral responses of the nanomanufactured
films. Here an undergraduate will nanomanufacture a standalone diffraction grating
built entirely from magnetic nanoparticles, and will then test that grating in an
optical spectrograph test-bed. In addition to studying diffracted spectra and how
the spectra depend on the nanomanufacturing process, the student could move on to
study changes in the film’s optical properties in response to both thermal and magnetic
stimuli.
Large language models like ChatGPT are poised to become an essential component of
education. Dr. Crittenden aims to develop a system of interacting AIs that behave:
as a clone of the instructor, as a peer mentor, as a graduate-level tutor, and as
a performance assessor, all of which will work together, talking to each other, to
assist a hypothetical student taking a physics course.
Working directly with Dr. Crittenden, the REU student can be involved in every step
of the project. The student will learn multiple approaches to tuning the behavior
of AIs including prompt engineering and Retrieval-Augmented Generation and the use
of state-of-the-art AI system programming tools such as DSPy and LangChain to link
multiple AIs together to form a system that assesses and responds to a hypothetical
physics student. The goal is a team of always-available guides and assistants to
the physics student, tailored to each particular instructor's approach to every course,
rather than the average response that simply asking ChatGPT directly gives. There
will be a great deal of flexibility in the particular tasks the REU student will work
on, and no programming skill is required; AIs speak English and, moreover, they are
quite capable of assisting with any Python code that needs to be generated.
Theoretical research led by Dr. Gudkov is related to testing the standard model of
particle interactions and to the search for new physics in low-energy interactions.
This includes theoretical studies of the feasibility of searches for manifestations
of new physics beyond the standard model in fundamental neutron physics, with emphasis
on fundamental symmetries and "exotic" interactions. Research topics include studies
of time reversal invariance violation (TRIV) in neutron-nucleus scattering, parity
violating (PV) effects in nuclear interactions, and possible manifestations of new
physics in neutron decays and in interactions of neutrons with nuclei. The research
program provides theoretical support to the experimental programs in fundamental neutron
physics at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory,
the Japanese SNS at J-PARC, and the European Spallation Source, which are focused
on the study of neutron properties, neutron β-decay, neutron-antineutron oscillations,
and PV or TRIV effects.
A REU student working directly with Dr. Gudkov will learn basic approaches to the
study of symmetries in particle and nuclear physics and will contribute to computer
simulations of some proposed experiments. Many parameters related to reactions involving
neutrons and protons have, in recent years, been measured and evaluated by a number
of different groups. The student will work with this wealth of data to estimate the
strengths of PV or TRIV effects observable in the next generation of proposed experiments,
as functions of the neutron energies involved.
Prof. Rongying Jin’s research lies in the area of experimental condensed matter physics.
This is a highly interdisciplinary field requiring perspectives from physics, chemistry,
materials science, and engineering. The objective of her research is to apply the
experimental tools of materials synthesis, compositional tuning, and crystal growth
to address cutting-edge issues in quantum materials. Her effort has been devoted
to (1) the development of new quantum materials with intriguing properties (superconductivity,
quantum magnetism, nontrivial topology, thermoelectrics, multiferroics, etc.); (2)
the investigation of physical properties: charge, spin, and heat transport, magnetization,
specific heat, microscopic (magnetic force microscopy, scanning tunneling microscopy,
transmission electron microscopy), and spectroscopic (angle-resolved photoemission,
and neutron scattering) measurements; and (3) collaboration with theorists/computational
scientists for atomic-level understanding of the observed phenomena. Under the guidance
of senior researchers (postdoctoral fellows and graduate students), REU researchers
will have opportunities to participate in materials synthesis and/or physical properties
measurements including electrical, magnetic, thermal, and thermodynamical properties.
Particle theory research led by Dr. Petrov pertains to understanding the structure
of the fundamental electroweak Lagrangian at the smallest scales and developing theoretical
tools needed for the "clean" interpretation of results from experiments probing the
origins of mass and CP-violation. In recent years, Dr. Petrov has worked on various
problems in the theory and phenomenology of strong, electromagnetic, and weak interactions.
REU research topics include studies of the properties of heavy hadrons, applications
of effective field theories to problems in quantum chromodynamics (QCD), particle
astrophysics, neutrino physics, and the physics of CP-violation. The research program
significantly overlaps with the current research interests of USC's experimental particle
and nuclear physics groups.
A student will learn and apply numerical fitting techniques used in the studies of
charmed meson decays under various flavor-SU(3)-breaking assumptions. The student's
primary task would be to learn and apply fits of theoretical parameters describing
meson decays to experimental data. The fits produced by the student will be the main
outcome of the summer project.
In 2010, high-precision studies of muonic hydrogen found notably smaller values for
the proton charge radius than earlier results that have been extracted from elastic
electron scattering data and through the spectroscopy of atomic hydrogen. The MUon
Scattering Experiment (MUSE) at the Paul Scherrer Institute has been developed by
an international collaboration of researchers to address this "proton-radius puzzle."
The experiment will measure elastic electron-proton and muon-proton scattering data
with positively and negatively charged beams in a four-momentum-transfer range from
0.002 to 0.08 GeV². Each of the four data sets will allow the extraction of the proton
charge radius. In combination, the data test possible differences between the electron
and muon interactions and provide novel data on two-photon exchange effects in the
scattering process. Dr. Strauch is the spokesperson for the experiment. His group
has built two double-plane time-of-flight scintillator walls, veto detectors, and
beam-line monitors for MUSE. The present efforts include the development of a full
Monte Carlo simulation of the experiment, the study of radiative corrections, and
the analysis of calibration and first production data.
Three USC graduate and 15 undergraduate students have worked on research projects
related to MUSE; three of them were REU students. Topics for future REU students
include a Monte Carlo simulation of the time response for the MUSE scintillation detectors,
the improvement of the experiment model in the simulation, the study of background
from particle scattering off inactive support structures in the experiment, the development
of procedures to monitor and determine detector calibrations from production data,
the improvement on the digitization of simulated data and comparison of the results
with data, and analysis of time-of-flight data to determine the muon beam momentum.
These projects will be performed under the supervision of Dr. Strauch, with the collaboration
of the graduate students in the experimental nuclear physics group. The participants
will also be part of meetings involving the other two faculty members in the group,
as well as outside collaborators.
The main focus of Dr. Wu's laboratory is on using nonlinear optical second harmonic
generation (SHG) polarimetry technique to investigate interesting phase transitions
in a variety of fascinating quantum materials, including superconductors, topological
insulators, semi-metals, etc.
A student working on this project will first complete a week of rigorous training
on how to handle and set up optical components (such as mirrors and lenses) safely
and how to use them to excite and collect optical signals from a practice sample.
They will learn about the basics of material properties, such as crystal symmetries,
and how they can be identified using SHG. They will learn how to clean and prepare
samples for optical measurements during the second week and will discover how to use
x-ray diffraction to perform preliminary measurements in order to first identify the
target crystal plane for SHG. The majority of their time will be spent actively collaborating
with a graduate student in Dr. Wu's group, collecting SHG data as a pair. The REU
student will also participate in the data analysis process, using programs like Igor,
Python, and Mathematica.
Dr. Wu will be closely monitoring the progress of the REU students. In addition to
a traditional lab notebook, they will be expected to keep a Powerpoint research journal
with thorough notes, illustrations, and graphs. In addition to their experimental
results, their research journals will include information gleaned from the scientific
literature, which they will be reviewing with Dr. Wu's guidance. During the weekly
research group meetings and Zoom meetings with collaborators, they will present their
overall progress and outcomes using the Powerpoint diaries. The students will attend
the SmartState weekly journal clubs, where they will be exposed to the latest research
on relevant topics. In addition, they will be given the opportunity to present a
journal article to the center members. They can polish their scientific communication
skills in a welcoming and encouraging environment during group meetings and journal
clubs.
Dr. Tahani has led the upgrade of a unique telescope design known as the Dragonfly
Telephoto Array (Dragonfly) to enable optical polarization observations through the
new Dragonfly Polarimetry (DragonflyPol) capability. She is currently leading wide-field
optical polarization sky surveys and targeted observations that, for the first time,
provide sensitive, wide-area maps of faint optical polarization across diffuse Galactic
and cosmic environments. These data open a new window on how interstellar dust, scattering,
and magnetic fields shape the Milky Way and other astrophysical systems. The team
has been observing a range of environments, including regions influenced by energetic
events such as supernova remnants. These observations enable senior undergraduates
to work with frontier datasets and build strong skills in calibration, data reduction,
analysis, and programming.
Dr. Tahani’s group currently includes two PhD students, two undergraduate researchers,
and an incoming postdoctoral scholar, and is part of international collaborations
with colleagues around the world. With a mix of physics and astronomy backgrounds,
the group emphasizes careful mentorship, collaborative problem-solving, and a welcoming
research environment. REU students will gain both independent and team-based research
experience across the full workflow; from data reduction and quality assessment to
data processing, analysis, and scientific interpretation. Students will develop skills
in observational astronomy and computational analysis while contributing to projects
that trace the “invisible threads” of magnetism in the Universe.
Applying pressure is a powerful method for modifying the crystal structure and physical
properties of materials, often uncovering novel magnetic and electronic states that
cannot be accessed through other means. In this REU project, the undergraduate student
will explore how applying pressure changes the behavior of quantum magnetic materials
and drives them into new phases. This project is designed for students with a strong
interest in hands-on experimental research and discovery.
The student will gain research experience with high pressure techniques and learn
how to generate extreme pressures in the laboratory. They will perform low-temperature
electrical transport and magnetic measurements to observe how material properties
change under compression and learn how to analyze and interpret experimental data.
In addition, the student will have the opportunity to travel to national user facility,
such as the Advanced Photon Source at Argonne National Laboratory to participate in
synchrotron X-ray experiments. This experience will introduce the student to large-scale
research facilities and provide training in the basic principles of X-ray physics
and data analysis, while exposing them to collaborative, team-based scientific research.
Challenge the conventional. Create the exceptional. No Limits.