Taking the SMART Path

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Category: Department News

Published: Thursday, January 26 2023 00:01

In 2021, when Isabelle Brooks left her home in Minnesota to study physics at the University of Maryland, she knew it would mean a big transition—from an all-girls high school with fewer than 500 students to a huge college campus with more than 40,000 students. It turned out to be even more exciting than she expected.

“It was definitely a culture shock,” Brooks recalled. “I told my roommate it was crazy to me that I kept seeing so many faces I didn’t recognize. I was around so many different people doing so many differIsabelle Brooksent things—it was a really cool and exciting experience.”

Brooks’ experiences have exceeded her expectations in more ways than one, and although she’s only a sophomore she’s already charting her path toward a career in physics. One big boost in that direction came last year when she was awarded a Department of Defense SMART (Science, Mathematics, and Research for Transformation) Scholarship. 

SMART Scholars receive full tuition for up to five years and hands-on internship experience working directly with an experienced mentor at one of over 200 innovative laboratories across the Army, Navy, Air Force and Department of Defense, plus a stipend and full-time employment with the Department of Defense after graduation. 

This summer, Brooks will intern at a U.S. Army facility in Maryland. 

“I’ll be working at Aberdeen Proving Ground with the Department of Defense,” Brooks said. “The lab I’ll be working with focuses on satellite communications and other innovative technologies for our armed forces. It’s super exciting.”

Physics in the family

Always a strong student, Brooks got an early introduction to physics thanks to her father who studied physics when he was in college.

“My dad was my biggest influence,” she explained. “He’s a patent attorney now and he works with a lot of science and technology, which has been super cool to watch as I’ve been growing up.”

Despite her interest in her dad’s work, Brooks wasn’t initially drawn to physics herself.

“My dad was always like, ‘It’s really important to study science,’ but I didn’t really want to,” Brooks recalled. “My freshman year in high school I actually did not do well in my introductory physics class at all, I didn’t like the content and I told my dad, ‘I’m never doing this.’”

All it took was one class to change her mind.

“In my senior year I ended up taking honors physics and I had the best, most supportive most influential professor who helped me understand that I am really good at this and there is an opportunity for me to do much more with it,” she said. “After that, it really made sense to me—I liked seeing how physics is playing out in the real world, and I knew this was something I wanted to do.”

So many possibilities

In the summer after Brooks’ first year at UMD, one of her relatives who works with the Defense Department encouraged her to apply for the SMART Scholarship to help her achieve her dream of a degree in physics. Months later she got the news she was hoping for.

“I was checking my inbox every day and when I saw the email I was shaking because I knew this had to be it,” she recalled. “When I opened the email and got the good news that I’d received the scholarship I just felt so honored. There are just so many possibilities that can come from this.”

Since then, regular check-in meetings with her SMART mentor James Mink, Chief of the Tactical Systems Branch (SATCOM) have helped Brooks learn more about the opportunities ahead and prepare for her summer internships. This summer—and every summer until she graduates—she’ll work directly with her mentor at the U.S. Army DEVCOM C5ISR Center - Aberdeen Proving Ground, gaining valuable hands-on experience and training that will prepare her for a full-time position there after graduation.

Brooks credits her participation in the FIRE (First-Year Innovation and Research Experience) program and her work with the Simulating Particle Detection research group for helping her build a strong foundation for her research, which has also focused on the challenges of quantum Fourier transforms—mathematical models that help to transform the signals between two different domains. 

She’s gained more confidence in herself and her abilities every step of the way.

“My parents always raised me to believe I could do anything I put my mind to, overcome any obstacle, but I think coming to such a big school, at first I wasn’t sure if I could really do this,” she recalled. “But now I just feel like I’ve opened up so much more confidence in myself and an awareness of my ability and my strength as a student, and that feels really good.”

Brooks continues to explore her fascination with physics in exciting and unexpected ways, thanks to professors who challenge and inspire her. Her favorite class this year was PHYS 235: The Making of the Atomic Bomb.

“It’s taught by Professor Sylvester Gates, who I think is the coolest person ever,” Brooks said. “I was so excited when I was in that class, but it was definitely hard. If I wasn’t a physics major, I think I’d be crying with the problem sets we had and the material we worked on, but that class and a lot of my physics classes have pushed me to think in new ways.”

It's been less than two years since Brooks came to UMD from a small Minnesota high school, but now as she pursues her passion for physics and looks ahead to the opportunities that will come with her SMART Scholarship, she’s thinking big.

“I just have this feeling that I can do a lot more with my life and my education than I ever grasped,” she explained. “I think with this Defense Department scholarship I’ll most likely pivot towards applied research and satellite communication technology, and knowing that the work I’ll be doing will actually support people who fight for our country is incredibly amazing. I can’t wait to make a difference.”

Written by Leslie Miller

When Higgs Fly

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Category: Department News

Published: Thursday, January 26 2023 00:01

When Christopher Palmer was a physics graduate student at UC San Diego, he had to decide whether to specialize in supersymmetry or search for the Higgs boson.

Though there was no experimental evidence of the Higgs boson’s existence at the time, Palmer was convinced that this elusive elementary particle—believed to be linked to a field that gave mass to everything in the universe—was somewhere out there.Chris Palmer

“The Higgs boson is such a cornerstone of a very well-established theory called electroweak theory,” Palmer said. “It could be a lack of imagination on my part, but I could not imagine the Higgs boson not existing.”

He trusted his gut and dedicated his studies to the Higgs, which set him on course to Switzerland to join one of the experiments at the Large Hadron Collider (LHC) beginning in 2010. Luck was on his side, and he ended up being part of the research group that recorded the highest number of Higgs bosons in their analyses, contributing to the particle’s official discovery the following year.

He hasn’t looked back since. In March 2021, Palmer became an assistant professor of physics at the University of Maryland, where he continues to study the Higgs in search of the next big discovery.

‘Deeply weird’ physics

Palmer’s first academic love wasn’t actually physics—it was math.

“I loved math in high school, so I thought, ‘Yeah, I’ll do math in college,’ but that was sort of my ‘hobby major’—and I’m glad it was because I ended up not enjoying mathematical proofs that much,” he said with a laugh.

A fascination with what existed “beyond Earth” prompted Palmer to declare a second major in astronomy as an undergraduate student at USC. But it wasn’t until he took an upper-level course in quantum mechanics—and became enamored with its mathematical intricacies—that he developed a deeper appreciation for physics. 

“It was a new way to use many different aspects of math,” Palmer said. “There’s linear algebra and complex numbers. Taking these integrals and mixing all that up in a pot was really fun for me. But there was also some new physics that was deeply weird, and I couldn’t get enough of it.”

Palmer needed only one quantum mechanics course to meet the requirements of an astronomy major but enjoyed it so much that he took two. After graduating with a bachelor’s degree in mathematics and astronomy in 2007, he took a short drive south to UC San Diego to continue his studies—this time as a Ph.D. student in physics.

Right place, right time

Once Palmer decided to search for the Higgs boson, he joined the Compact Muon Solenoid (CMS) experiment at the LHC. Palmer teamed up with a group that was looking for evidence of the Higgs boson’s decay into two photons during proton-proton collisions.

This turned out to be a serendipitous assignment. His group ultimately saw an enormous excess of Higgs bosons in their analysis. 

“At the time in 2011, no one else at CMS had actually seen much of anything in their data, and in my analysis there was the biggest excess of Higgs boson particles in any of CMS’ searches,” Palmer said. “The discovery was literally happening at my fingertips.”

Palmer was so focused on the work that he didn’t have time to get excited about the actual discovery of the Higgs boson, which was confirmed and publicized in 2012.

“There was a whole lot of double- and triple-checking everything in early 2012. I wasn’t sleeping all that much,” he said. “I got excited afterward.” 

With one major discovery under his belt, Palmer was hooked on Higgs. After earning his Ph.D. in 2014, he became a postdoctoral researcher at Princeton University, where he participated in luminosity experiments and studied the Higgs boson’s decay to bottom quarks—the “most elusive decay” anyone had observed up to that point. 

In 2021, Palmer joined UMD with plans to study signatures of the Higgs boson in greater detail and depth, while also having the flexibility to explore other research interests down the line. 

“One of the things that I really love about this department is that there are so many different types of research that are represented by the faculty,” Palmer said. “In 10 years, if I want to do something different, I don’t know any place where it would be easier.”

Continent-spanning research

Palmer continues to participate in LHC experiments, and much of his work can be done without ever leaving campus. He is part of a team that is studying a new CMS detector, called the MIP Timing Detector, that will more precisely measure charged particles. Because the CMS experiment will need to be operational at -30 degrees Celsius, Palmer and his team are building a cold box at UMD to test components of the detector under extreme conditions.

This research is funded by a Department of Energy grant, which also supports the work of Physics Professor Sarah Eno and Associate Professor Alberto Belloni. Though all three faculty members are involved in LHC experiments, Palmer said they each have their own interests and areas of expertise, which keeps things interesting.

“It’s nice to see what other people are doing, and you don’t always get that when you work in a group that has all the same physics interests,” Palmer said. “It’s also good for the students because they really get to see what is going on in vastly different corners of the experiment, which is important in a giant experiment like CMS that has 3,000-some people in it.” 

In addition to his research, Palmer works to make physics a more inclusive field and is currently exploring ways to improve student mentorship and support for students from historically underrepresented groups. He serves on the executive committee of the American Physical Society’s Forum on Diversity & Inclusion, as well as the College of Computer, Mathematical, and Natural Sciences’ Diversity & Inclusion Advisory Council. He is also the director of Pathway to Physics PhD (P3), a UMD fellowship program that offers fully funded physics degrees, with priority given to applicants from historically Black colleges and universities and minority-serving institutions.

Eye on the collider

When he’s not busy with campus initiatives or teaching classes, Palmer keeps tabs on the data flowing out of the LHC. A monitor next to his office door displays numbers and charts showing the latest data from LHC experiments, including the luminosity measurements that Palmer specializes in. 

“Most of the time I’m engaged in my classes and meetings and other things that I’m immediately involved with,” Palmer said, “but I’m always keeping an eye on what’s going on at the LHC out of the corner of my eye.”

Palmer’s research—and a touch of luck—brought him face-to-face with some of the biggest discoveries in physics. When the next uncharted phenomenon shows up in an experiment, Palmer doesn’t want to miss it.

Written by Emily Nunez

Calling All Experimentalists, Designers, Fixers and Tinkerers

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Category: Department News

Published: Thursday, January 26 2023 00:01

Two of the best-kept secrets in the University of Maryland’s Department of Physics are its Vortex Makerspace and a small class held in the makerspace that is dedicated to the practical skills needed for physics experimentation.

Since 2019, Professor Daniel Lathrop has taught a unique 400-level laboratory course in the Vortex Makerspace (formerly the Physics Welding Shop), which is tucked behind the John S. Toll Physics Building. Designed to teach students hands-on ways to bring their ideas to life, the class touches on topics such as carpentry, circuitry and 3D printing. Lathrop guides the students as they design, plan, build and demo their creations inspired by the semester’s physics lecture topics. But it’s not all about a student’s ability to build from scratch, Lathrop said.

“One thing I really wanted to accomplish with this class was to expose students to skills that they wouldn’t usually come across in their conventional classroom studies,” Lathrop explained. “That not only includes how to make things with their hands but also how to develop soft skills like leadership, budgeting, communication and teamwork—all qualities that are needed in real-life careers in physics.”

To simulate the kinds of situations, goals and challenges that physics experimentalists often encounter, Lathrop wove together 12 weeks of interactive lectures, field trips, training sessions and demonstrations. As his unique lesson plans for the class quickly spread by word of mouth, physics majors eager for a more hands-on learning experience registered for the class.

One of those students, Alexandra Pick-Aluas (B.S. ’22, physics), first heard glowing reviews about Lathrop’s class from two friends and was intrigued by the prospect of a lab elective that could give her a sneak peek into the professional future she hoped to pursue. She realized quickly that the class was unlike any she’d ever taken. 

“We were given an introduction to welding, which was obviously something I never tried before,” Pick-Aluas explained. “I learned how to weld pieces of metal together and got to see the difference in outcomes for the different metals I used. For example, aluminum is really easy to melt and that’s one reason why it’s a notoriously difficult metal to weld. It’s one thing to read about it, but it’s a much more enlightening experience to actually see it in action in front of me.”PHYS 499X students demonstrate their Spring 2022 semester project, a liquid nitrogen-cooled superconducting loop. From left to right: Peiyu Qin, Alexandra Pick-Aluas, Meyer Taffel, Noah Doney, Ankith Rajashekar, Brian Robbins, and Dylan Christopherson. Image courtesy of Daniel Lathrop.

Welding was just one skill Pick-Aluas developed during the class. For their final project, Pick-Aluas and her group members built a superconducting loop—an infinitely flowing electric current with no power source—with materials like scrap metal, a bicycle wheel spoke and superconducting tape. Guided by Lathrop, they designed a suitable prototype within a limited budget, ordered their required materials from specialized vendors, constructed their design and wrote a manual explaining how their project functioned.  

“Even though our project didn’t exactly work the way we originally wanted it to, the entire process it took to make the superconducting loop is something I’ll always remember,” Pick-Aluas said. “Professor Lathrop says that in reality, failures and setbacks should be expected before making progress.”

She hopes that more physics majors take PHYS 499X before they graduate. For Pick-Aluas, who is now assisting Lathrop in his lab as she prepares for graduate school, the expertise she gained from the course helped shape her own career goals. 

“At first, I was a little intimidated, but the class made me feel a lot more comfortable with these skills. Potentially applying them on the job is a little less daunting to me now,” Pick-Alaus explained. “PHYS 499X is a really good overview of what you can expect in a real-life physics-related profession, whether it’s in academia or in industry.” 

Beyond the class, physics majors can also use the Vortex Makerspace—which is housed within the same single-room building as PHYS 499X—for all their experimentalist aspirations. Thanks to key efforts from UMD Physics Director of Education Donna Hammer, Vortex provides a dedicated time and place for students to work on meaningful projects of their own. Equipped with saws, welders, wires, wrenches and other knickknacks ready for students to use, the makerspace also encourages students to walk in and chat with Vortex’s ‘shop managers’ if they need additional guidance, resources or someone to simply bounce ideas off of.

“We’re open four afternoons a week to anyone during the semester—no experience or background necessary,” said Jake Lyon, a senior physics major and vice president of the Vortex Makerspace. “Vortex frequently holds training sessions and workshops for a variety of topics, like intro into basic coding or circuitry.”

Jake Lyon (right) teaches a student how to solder a simple circuit at the UMD Physics Vortex Makerspace.Lyon became involved with the makerspace as a sophomore. Over the next few years, he attended a variety of training sessions and eventually developed an arsenal of handy skills from 3D printing to soldering. Then he tested this newly acquired knowledge, applying it to the projects he took on at the makerspace, including his personal favorite, fixing a broken megaphone. He believes taking the megaphone apart, figuring out how it worked and diagnosing what went wrong was an experience that will stay with him long after he graduates.

“The Vortex is a fantastic place to learn and get comfortable with the basic parts of fabrication with the right equipment while also getting to know the physics makers community,” Lyon said. “We facilitate learning but try to encourage teamwork and communication with everyone as well.”

In addition to the activities held during the semester, the Vortex Makerspace also offers a series of summer programs, including the Physics Makers Camp for high school students looking to get a head start on creative thinking and design, run by Outreach Coordinator Angel Torres. And although Vortex is run by physics undergraduates, Lyon said the organization welcomes anyone who wants to bring a project to life.

“We have a good lineup of ideas for workshops in the spring semester, so anyone—including non-physics majors—looking to acquire a new handy skill or two is welcome to stop by,” Lyon said. “Just bring an idea and we’ll bring the tools.” 

Written by Georgia Jiang 

Nathan Schine Twists Photons and Cools Atoms in a Unique Quantum Dance

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Category: Department News

Published: Thursday, January 26 2023 00:01

Deepening our understanding of the quantum world and developing new tools to peer into it is a very active area of physics research today. In this crowded field full of diverse theoretical ideas and physical tools, Assistant Professor and JQI Fellow Nathan Schine has managed to carve out a distinctive space for himself and his lab.Nathan Schine

Schine’s research program manipulates the interactions between atoms and photons—the particles that make up light—in novel, well-controlled ways in order to simulate other, harder-to-probe quantum phenomena. To coax the photons into new simulation patterns, Schine is using unique arrangements of mirrors to bounce photons around. He is also strategically placing atoms in the photons’ way with the help of precisely controlled laser beams. To boot, the atoms he is using (ytterbium) have a relatively complex structure, giving Schine extra avenues to explore. He has been able to create this unique niche by combining the experimental expertise he gained from graduate school and postdoctoral research with his theoretical big-picture savvy.

Schine has been slowly homing in on his academic sweet spot for much of his life. Growing up, his interests were broad—they included science and math, but also history and other areas of the humanities. “It wasn't like I knew from an early age that I was going to go be a physicist,” Schine says.

Science wasn’t outside the realm of Schine’s imagination, however. His father was a chemistry teacher, his mother had a degree in math, and his grandfather was a physics professor at Vanderbilt University. 

Keeping his options open, Schine attended Williams College. Ranked first among U.S. liberal arts colleges by U.S. News and World Report, Williams boasts an unusually strong science and math program. Schine was interested in math, but eventually found it to be too abstract for his taste. “When math got into proving the existence of a solution to a problem and not actually solving the problem, I sort of lost the thread a bit,” he recalls. Instead, he found that the part of math he enjoyed most could be gotten through physics, so he dove deeper into the subject. 

An undergraduate research project sealed the deal for Schine as a physicist and experimentalist. He started working in the lab of his soon-to-be quantum mechanics professor, Barclay Jermain Professor of Natural Philosophy at Williams Protik Majumder, midway through his sophomore year.

Under Majumder’s supervision, Schine started to get a taste for experimental physics. He was performing spectroscopic measurements on indium atoms as a sophomore and continued working with Majumder until he graduated. Indium, with its three loosely bound, outermost electrons, is hard to model theoretically, and Majumder’s lab collaborated with theorists to benchmark their calculations and zero in on precise values. 

Schine relished the chance to make a real contribution to the project. He also found joy in tinkering in the lab, finding his calling as an experimentalist. “I liked the day-to-day aspects of it, the actual process of building a laser or something,” Schine says. “A lot of it is very tactile and building up this sort of Rube Goldberg device that happens to be useful for physics—that, I think, is a lot of fun.”

Majumder had a slightly different take on what set Schine apart in his lab. “He was really unusual, even as a 20-year-old, in being able to balance comfortably the very hands-on build stuff with the bigger intellectual picture, which is obviously something that's been characteristic of his career since then,” Majumder says. Schine’s research with Majumder culminated in a senior thesis and a peer-reviewed publication. 

Schine was inspired by his undergraduate research experience and decided to pursue graduate school. His chops setting up lasers and other experimental equipment meant he could hit the ground running and start contributing right away to the brand-new lab of Jonathan Simon at the University of Chicago. 

The lab Simon was envisioning involved filling an optical cavity—a set of mirrors trapping light and bouncing it back and forth between them—with ultracold rubidium atoms. The idea was to use the photons themselves as a quantum playground, used to re-create and study quantum phenomena that happen in other, less accessible settings. 

A lot of the interesting quantum phenomena that appear in real materials are hard to peer into at the quantum level but are nevertheless important for our daily lives because of their ubiquitous applications in technology. In Simon’s lab, precisely controlled photons can play a similar role to electrons inside of a material. Studying how these photons behave in a cavity and measuring them directly can then give clues about what happens inside the chunks of material. 

There is one obvious limitation for photons playing the part of electrons: They don’t have an electric charge. And charged electrons—specifically in magnetic fields—are responsible for a range of interesting material effects that might need simulating. 

Back in the early 1980s, physicists discovered one such effect.  A thin layer of semiconductor placed inside a strong magnetic field was found to conduct electricity in very precise chunks. As the magnetic field is increased, the conductivity doesn’t change for a while—it stays at one plateau—and then hops abruptly to another plateau. This is known as the integer quantum Hall effect (IQHE) because the plateaus appeared at very regularly spaced integer values.

Even more strangely, for very cleanly engineered semiconductors, experimentalists found sub-plateaus within the plateaus, appearing at precise fractions of the previous integer values. They termed this, predictably, the fractional quantum Hall effect (FQHE). The origins of these fractional plateaus are largely still a mystery, although physicists are pretty certain that it has something to do with interactions between electrons giving rise to unexpected collective behaviors. If there was a way to simulate the full quantum theory of the FQHE, it might reveal new insights into what’s going on. 

Simon and Schine, along with their labmates, hatched a plan. They conceived of a new way to make photons behave as though they have charge and live in a magnetic field that could, in principle, allow the photons to interact with each other and simulate the FQHE. Their plan involved a wonky cavity: four mirrors aligned to bounce light around in a twisted bow-tie configuration over and over again, with one of the mirrors slightly askew, as in the diagram shown below.

Photons and atoms in Schine’s tilted bow-tie cavity. (Credit: Nathan Schine/JQI)

Schine and his labmates focused on what happened along a plane at the center of this cavity. There, the photons were analogous to electrons traveling inside a thin material like in either of the Hall effects. The twisted mirror configuration causes the photons to twist around, much like electrons precess around inside a magnetic field. 

With careful cavity design, they were able to make the analogy come to life and make their photons replicate the IQHE in its full glory. They published this result in the journal Nature. 

To go beyond integer quantum Hall physics, the particles need to interact with one another—not just pass through each other, like photons are wont to do. That’s where atoms entered the picture. Previously, scientists had worked out a technique that allows atoms to serve as an intermediary through which photons can talk to each other. 

In parallel with the twisted cavity work, Simon’s lab had been working on this atom-assisted approach to making photons interact with each other. This involved cooling a gas of rubidium atoms to extremely low temperatures, just a touch above absolute zero. Then, the light was tuned to a particular color that would allow one of the rubidium atoms to absorb a single photon. This atom then prevented any nearby atoms from absorbing a photon, ensuring no other photon got too close. This created an effective interaction between photons, where they were averse to being too close to one another. 

The next step was to combine the two techniques: put the rubidium inside the skewed bowtie cavity. The cavity makes photons act like electrons in a magnetic field, and the atoms create a medium through which the photons can interact. The combination created the right conditions for FQHE physics. Although short-lived, the photons in Schine’s experiment appeared to indeed exhibit the hallmarks of fractional quantum Hall physics. Schine and his labmates published this result in the journal Nature. 

This was the first time the fractional quantum Hall effect had been simulated in any medium. For his graduate work, Schine was named a finalist for a thesis prize from the American Physical Society’s Division of Atomic Molecular and Optical Physics, the most prestigious thesis award in this field. 

Schine was still circling around his ultimate niche, though, and he sought to broaden his experimental skillset during his postdoctoral studies. He joined the group of Adam Kaufman at JILA at the University of Colorado Boulder (sometimes snarkily called JQI West). Kaufman’s lab manipulates atoms with light, using a tool called optical tweezers—laser beams focused down to a very narrow spot, intense enough to hold an atom in place. 

Schine, Kaufman, and collaborators used these optical tweezers to put a new spin on atomic clocks, which are the most precise timekeepers we have. They work by counting the intrinsic ticking of individual atoms. Precise as they are, scientists are actively working on making them even more so, both for better technology like navigation and geolocation and for scientific inquiries, like the basic nature of fundamental constants and gravity. 

The team endeavored to use a fundamentally quantum property—entanglement—to make pairs of atoms tick in tandem, thereby making the clock more precise. They cooled a gas of strontium atoms just above absolute zero and used optical tweezers to create a large array of atom pairs. These pairs were then made to interact using the same trick Schine had used during his graduate work: one atom absorbing a photon prevented another atom nearby from doing so as well, thus making their behavior depend on one another. Generating entangled atoms like this is a promising way to improve clock performance. They published this work in the journal Nature Physics. 

Now, Schine is starting to build up his own lab here at the University of Maryland. When deciding exactly what kind of experiment to embark upon, Schine was guided by his graduate school advisor Simon’s philosophy. “There are different strategies for setting up experiments,” Schine says. “But I think Jon’s was very much to build something that no one else has done before experimentally—to put ourselves in an area where there's a lot of low-hanging fruit.” Schine explained that this will involve combining his optical cavity expertise with an array of tweezer-trapped atoms, now using ytterbium. For instance, he predicts this will allow dramatic improvements in performing quantum measurements, which is an essential part of quantum computing or quantum simulation experiments. 

As Schine is assembling his lab and unique research program, he encourages interested students and postdocs to reach out to him. And, according to Schine’s undergraduate adviser, Schine’s teaching and mentoring abilities promise to be excellent. “One of the things we really work hard at in a place like Williams,” Majumder says, “is to make sure our students are not just the ones who can get into the lab, hide in a corner and just do amazing work. And that really comes through with Nathan. He's just such a good explainer of what he's doing. And he's so enthusiastic—it's very infectious.”

Story by Dina Genkina