## Research Opportunities

There are ten research areas currently offered as part of the REU program:

- Computational Astrophysics
- Experimental Condensed Matter Physics
- Accelerator physics
- Nuclear Experiment
- High Energy Physics
- Experimental Atomic and Molecular Optics (AMO)
- Theoretical AMO/Condensed Matter
- Theoretical Cosmology
- Computational Condensed Matter
- Laser Teaching Center

1. Computational Astrophysics (mentors: Alan Calder / Michael Zingale): Our computational astrophysics group is active in simulations of stellar phenomena (including various models of supernovae, X-ray bursts, novae) and related topics (exoplanet structure). We develop a suite of open source simulation codes that solve the equations of hydrodynamics on adaptive structured meshes, and are written to perform on modern supercomputers. For an REU student, we would offer a choice of project, involving:

- Performing simulations of a new science problem (likely 2-d, exploratory calculations)
- Working on visualization of simulation data
- Adding to and testing our microphysics (nuclear reaction networks, equations of state, etc.)

We would need a student who already has familiarity with programming (we use C++, Fortran, and python primarily). Working in our group, we will train the student on modern software engineering techniques, including version control with git, testing, and debugging.

2. Experimental Condensed Matter Physics (mentors: Matthew Dawber/ Xu Du/ Mengkun Liu): There are three highly active experimental condensed matter groups with labs on-site in the physics building at Stony Brook. The groups operate in a highly collaborative fashion with students working in one group having access to the equipment in the labs of the other groups. There are also common items of equipment and these are being expanded and consolidated in to a new jointly space over the next year. The focuses of the three groups are

- deposition and characterization of complex oxide thin films and multilayers (Dawber)
- Electrical transport and device physics with a focus on 2D materials (Du)
- Ultra-fast and near field IR spectroscopy (Liu).

The groups are also extensive users of nearby user facilities at BNL, in particular beamlines at NSLS-II and the nanofabrication facilities at the CFN which complement our in-house facilities. REU students working in this area would be doing very hands-on projects mastering a number of experimental apparatus. The groups have hosted many undergraduate researchers to date and also typically host an average of 3 high school students each summer through the Simons Summer Research Program. These groups could support from one to two students in each summer of the program.

3. Accelerator physics (mentor: Navid Vafaei-Najafabadi): Accelerator physics is a growing area of research with many exciting opportunities for undergraduate students in both conventional accelerator physics as well as advanced accelerator technology. The connection of the Stony Brook faculty to the Brookhaven National Laboratory (BNL) provides a unique opportunity for undergraduate students to engage in research in collaboration with a world class accelerator facility. This connection is further reinforced by Center for Accelerator Science and Education (CASE), which seeks to train the next generation of accelerator scientists and engineers. This organization is supported by the resources and active participation of staff from both BNL and Stony Brook University. The students will be able to contribute to the experiments in the field of plasma-based particle accelerators, where accelerating forces a thousand times greater than the conventional particle accelerators can be generated. One such experiment currently under way uses the laser and electron-beam facilities at the Accelerator Test Facility at BNL to experimentally study the properties of plasma waves generated by lasers. This project will give the students hands on training on a number of areas, including particle acceleration, high power laser physics, laser and particle beam diagnostics, and scientific data analysis. Example of previous projects by undergraduate students include writing data acquisition and analysis software, studying and designing plasma and electron beam diagnostics, and testing the experimental apparatus.

4. Nuclear Experiment (mentors:
Abhay Deshpande,
Klaus Dehmelt,
Axel Drees,
Tom Hemmick,

Joanna Kiryluk): Our Nuclear Physics program is ranked 3rd in the United States, and
our experimental group offers a number of exciting projects for undergraduates.

The relativistic heavy ion group (PI’s Hemmick, Drees, and Dehmelt) had established a long history of mentoring REU students in the last period of NSF support and typically took three such students each summer. The current projects involve three basic thrusts:

- sPHENIX is an upgrade to the PHENIX experiment (for which SBU held a leading role). SBU is in charge of the construction of the Time Projection Chamber (TPC) for sPHENIX. Opportunities range from physics simulation, to mechanical design, to electronic design, to test beam experiments, and finally construction and commissioning of the detector itself.
- SoLID is a newly proposed experiment at Jefferson Lab that will investigate deep inelastic scattering (DIS) and parity-violating DIS using the recent upgrade of CEBAF to 12 GeV. SBU is doing R&D and will perform construction of the high reflectivity mirrors for the SoLID cherenkov detector. This work involves high vacuum work.
- The Electron-Ion Collider (EIC) is listed in the nuclear physics long range plan as the top priority for new construction. SBU has been a leader in the R&D program developing new detector technologies for EIC. This work has included unique large area gas-based Cherenkov detectors, standard TPC’s, and TPC specializing in particle ID through the development of “cluster counting techniques”.

The research involves both bench experiments as beam experiments to build and prove new technologies. The effort at JLab focuses on parity violation experiments and precision electron beam polarimetry needed for the success of those experiments. The list of experiments is long, but the principle ones include PREX/CREX, MOLLER and SOLID. All of these are planned in the next 2-7 years using the 12 GeV upgraded Continuous Beam Accelerator Facility (CEBAF). REU projects associated with these experiments would involve working on polarimetry, analysis of data in years 2019-onwards, and simulations of detector responses for those being designed at this time.

Joanna Kiryluk is part of the IceCube experiment at the South Pole which studies the Universe by observing high-energy neutrinos. REU students will have the opportunity to participate in this cutting-edge science in the emerging field of neutrino particle astrophysics. They will contribute to analysis of existing and simulated data to reconstruct and identify the flavor of high-energy tau and electron neutrinos with deep learning (neural network) methods and techniques. Kiryluk will supervise one to two students annually.

5. High Energy Physics (Mentors: John Hobbs, Giacinto Piacquadio, Dmitri Tsybychev): The Stony Brook ATLAS group would like to propose 2 or 3 projects for undergraduate research under the supervision of Prof. J. Hobbs, Assist. Prof. G. Piacquadio and Assoc. Prof. D. Tsybychev. The group is co-leading several physics measurements based on the analysis of the proton proton collision data recorded with the ATLAS Experiment and delivered by the LHC accelerator at CERN in Geneva. These include the measurement of Higgs decays to b-quarks , the search for the rare Higgs decays to muons and the search for Higgs → aa → bbμμ, where a is a hypothesized new intermediate pseudo-scalar. The undergraduate research projects will be focused on one of these analyses. By now, a large dataset has been recorded at the unprecedented center of mass energy of 13 TeV, corresponding to approximately 140fb-1, thanks to the excellent performance of the LHC and of the ATLAS Detector. This performance comes at a price, and the analysis of the data has to cope with larger data collecting rates, making the online signal selection challenging, and with high contamination from pile-up, i.e. additional unwanted soft interactions that are the irreducible by-product of the higher rates.

Experimental progress therefore requires not only the analysis of the additional data, but also the design of smarter analyses. Understanding the physics of LHC collisions, how these are recorded with the ATLAS detector and how to deal with these challenges constitutes an intellectually stimulating environment for a student, at the same time it can be overwhelming if a student is not provided the right tools to filter out the relevant information. Therefore, for each of the students, one specific challenge will be isolated, for example the re-optimization of specific aspects of the analysis selection, which is typically connected to better understanding the features of the signal as opposed to the backgrounds, or a selective reduction of the contamination from pile-up, or a project to tackle a specific systematic uncertainty such as the b-jet calibration. The large data typically required for any of these analysis will be processed in such a way to present the student with data (real data and the corresponding simulated processes) in a format that can be typically analyzed on a single computer, and can be processed within a reasonable time.

The project will be divided in two phases. In the first phase, the student will be learning the skills needed to be successful on his project: on one side they will learn more about the physics of proton-proton collisions, and interactions due to quantum chromodynamics and electroweak processes, on the other side they will start to link this knowledge with the content of the data they are provided with, for which they will be learning the use of the ROOT software framework, using and potentially improving their C++ programming skills. In a second phase, when the student is confident enough about the tools used and the physics involved, the problem to tackle will be more clearly defined (also depending on the level of skills), and the student will be given at least one month to work on it. In all phases the student will be followed closely by both an experienced post-doc in the group and one faculty member, that will be identified among the faculty members of the group as responsible for a specific project. To maximize the probability of success, the problem to tackle will be “outsourced” from the original (and more complex) analysis, with the idea that, after successful completion, the findings will be integrated back into the main ATLAS analysis code. The project will end with a presentation to the ATLAS Stony Brook group’s weekly meeting and with a presentation of the results to the relevant ATLAS working group meeting.

6.
Experimental Atomic and Molecular Optics (Mentors:
Tom Allison,
Eden Figueroa,
Harold

Metcalf,
Dominik Schneble,
Tom Weinacht): Experimental AMO research in our department is carried on in five laboratories.
It spans an enormously wide range, covering almost all of the areas of current interest
in the field. All AMO faculty have welcomed undergraduates in our labs, and an REU
grant to our department would expand the possibilities to a larger and wider range
of students.

- In the time resolved spectroscopy lab under the guidance of Tom Weinacht, there are opportunities for students to design and test new optical systems for imaging, and manipulating the spatial and temporal properties of femtosecond time scale laser pulses. They could also work on developing software and hardware for data acquisition, as well as approaches for the interpretation of experimental measurements.
- The ultracold-atom lab under the guidance of Dominik Schneble produces gaseous atomic samples in the nanokelvin regime and studies their exotic quantum-mechanical behavior using advanced optical techniques. REU students would have the opportunity to learn about diode lasers and optics, ultrahigh vacuum, as well as data acquisition and analysis. They would be able to contribute through self-contained projects relating to laser stabilization, acousto-optics, optical atom trapping and imaging, and software and electronics development.
- Using polychromatic light to study ultra-strong optical forces on neutral He atoms is one topic of study in Harold Metcalf’s lab. One of the exploited transitions occurs in the telecom wavelength region so there is a wide range of fiber-optic instrumentation whose implementation for atomic physics is an extremely beneficial experience for students. There are Ti:Sapph lasers pumped by vanadates, fiber amplifiers, and of course, diode lasers frequency locked to atomic transitions and phase-locked to one another. Along with the physics of laser cooling and coherent exchange of momentum between atoms and light, the technological experiences has shown to be indeed important for students’ careers.
- The quantum information lab of Eden Figueroa offers summer projects for REU students to work hands-on in the laboratory. The projects are aimed at teaching students valuable experimental methods that are common in modern day quantum optics and quantum information research. Among possible projects are the construction and optimization of optical resonators, design of temperature-stabilized systems for nonlinear crystals, and the setting of an external cavity diode laser tuned to atomic transitions.
- The ultrafast, ultraviolet spectroscopy research in Tom Allison’s lab offers students the opportunity to learn about and use instruments in two extreme domains. These are times on the femto-second scale and on wavelengths that are invisible. The work seeks to unravel the complicated electronic and vibrational motions of atoms and molecules ionized by this kind of radiation.

7. Theoretical AMO/Condensed Matter (mentor: Tzu-Chieh Wei): The research interests in the group of Tzu-Chieh Wei include theoretical quantum information, condensed-matter physics, and quantum optics. He has extensive experience in supervising students at various stages for research, from high-school students to graduate students. For REU students, he has projects appropriate for junior and senior undergraduate students, briefly described below:

- Quantum information regards characterization of information processing under the laws of quantum mechanics, and the most notable potential applications include quantum computation and quantum communication. One important notion is entanglement. An REU project will expose students to this characteristic trait of quantum mechanics, how to characterize and quantify entanglement, and how entanglement can be used in various scenarios.
- Condensed-matter physics: REU students will learn essential theoretical and numerical tools to examine simple and yet nontrivial models. The numerical methods will include either Monte Carlo simulations or tensor-network techniques in solving many-body systems, either classical or quantum and will be applied to study phases of matter and their transitions.
- REU students interested in quantum optics will learn to characterize the quantum nature of light and how light interact with atoms. They will also interact with experimental groups and help to apply theoretical quantum optical tools to study experimental findings.

8. Theoretical Cosmology (mentor: Marilena LoVerde): The cosmology group at Stony Brook is active in a variety of research topics with connections to many other areas of physics, from particles and fields to astronomy. Theoretical cosmology research at Stony Brook spans the range of small pencil and paper or Mathematica-based projects to projects using large computer simulations to model the formation and evolution of structure in the Universe. An advanced undergraduate student would have the opportunity to get involved in a cosmology research at either end of the spectrum, depending on their background and interest. An REU student in this group would be offered a choice of project involving: producing visualizations of existing simulations of the gravitational evolution of structure, measuring new properties of large-scale structure in existing simulations, extending and testing a simple analytic model for new physics, or studying a toy model of a relativistic system. A student in this group would learn basic programming skills and good coding practices, and participate fully in the regular journal club and weekly meetings of the cosmology group

9. Computational Condensed Matter (mentors: Marivi Fernandez Serra, Phil Allen): The groups of Professor Marivi Fernandez-Serra and Professor Phil Allen have been collaborating since 2008. The research in both groups is focused on computational and theoretical condensed matter physics. The two groups are independent from an academic viewpoint, but students at the two groups interact are part of a single large group. Group meetings are common and often the two faculty will co-supervise each others students. This offers a very favorable and friendly environment for undergrad students interested on doing research in their area. Fernandez-Serra’s group is middle sized, with an average of 3 graduate students and one post-doctoral researcher. Undergraduate students often work with the group during the summer and both Professor Allen and Fernandez-Serra have covered summer students out of their research grants during the last 8 years. Fernandez-Serra regularly teaches the undergraduate course “PHY 277, Computation for Physics and Astronomy”. This is an introductory course to computational Physics and a number of students at the end of the course request to do a computational research project. Many of the undergraduate students that have worked with professor Fernandez-Serra have taken this course with her and ended doing a summer research project with her group.

Fernandez-Serra’s research is very multidisciplinary. In her group, students develop and apply methods to study the atomic and electronic dynamics of complex materials. One of the main research areas is the study of fundamental properties of liquid water using quantum mechanical simulations. They also apply their methods to study the interface between water and functional elements such as materials that can catalyze chemical reactions. This offers a plethora of research opportunities for undergraduate students with different interests. For those aiming to do a more computational project there are always new algorithmic and analysis tools to be developed. In particular, the group is currently developing a library of python subroutines to analyze order in complex systems using machine learning techniques such as deep neural networks and support vector machines. This is a very attractive computational project for an undergraduate student. The tools developed so far have only been used to study order in pure liquid water, but they can be extended to identify relevant chemical motifs at the water/solid interface that are favorable for for water dissociation, the splitting of water into hydroxyl (OH−) and proton (H+) ions. This is a necessary first step for the water oxidation reaction in which holes from the solid (semiconductor) material combine with the hydroxyl ions to produce molecular oxygen. At Fernandez Serra’s group research is ongoing to find optimal materials to catalyze this specific reaction. One very attractive side of this research is that the students also will get to interact with the group working on the experimental side of the same project (Professor Dawber’s group).

For students with less coding interests there are other projects, more applied, that
will involve learning to use an electronic structure code like “SIESTA”, a code for
which Fernandez-Serra is a co-developer. This will allow them to study in detail the
physical properties of a material of interest to the ongoing research within the two
groups. In particular, there is a large interest on studying the optical and transport
(both electrical and thermal) properties of materials. In the recent past, an undergraduate
student from Smith College, Carissa Moore worked with the two groups on a related
project, resulting in a publication [1]. The two groups are highly committed to undergraduate
education, and strongly encourage the participation of undergraduate students with
their groups. In addition, Fernandez-Serra is a core member of the Institute for Advanced
Computational Sciences (IACS).

10. Laser Teaching Center

The
Laser Teaching Center (LTC) housed in a dedicated 1100 square-foot suite, has been a permanent facility
within our Department, since its founding in 1995. Over the years we have mentored
and guided many dozens of students, roughly equal number of men and women, from a
widely diverse range of ethnicity and backgrounds. Students are guided by our carefully
chosen mentors for our summer program, but there are ongoing projects and tutorials
throughout the academic year. It provides hands-on, individual educational projects
in optical physics and technology for students at all levels, even our graduate students.
Our high school alumni are admitted to the highest ranking colleges in the country,
and our undergraduate alumni go to the very best graduate schools. Their career trajectories
are astounding: the LTC provides a launching pad for students into graduate school,
industrial and/or government labs, internships, and other career opportunities.

In the summer of 2016 the undergraduate projects included a method for broad-spectrum measurement
of retardation for characterizing unlabeled optical elements often collected in laboratories,
study of the diffraction patterns from cylinders offset parallel to laser beam propagation,
and the generation and conversion of transverse Gaussian laser modes into Laguerre-Gaussian
beams. Students working on all three of these projects were invited to present their
work at the 100th anniversary celebration of the OSA, in conjunction with the DLS’
Symposium on Undergraduate Research in October. In the summer of 2017 the projects
were the use of a cat’s-eye reflector to cancel the displacement of a beam diffracted by
an AOM so it can always be coupled into a fiber, use of an SLM to invert the effect
of an optical mode converter that produces Laguerre-Gaussian beams to measure its
effectiveness, and application of optical tweezers for laser trapping of polystyrene
microspheres. We envisage some REU projects could be done entirely within the LTC,
while for others the Center could play a role in providing resources to students doing
projects in AMO or Accelerator Physics.