UChicago students gain hands-on experience in quantum lab

A lightbulb didn’t go off for UChicago College student Diangen (Dana) Lin. Instead, inspiration struck with the glow of atoms.

While taking the Quantum Engineering Laboratory course at UChicago Pritzker School of Molecular Engineering, Lin was able to use a magneto-optical trap to laser-cool atoms very close to absolute zero.

“Once the atoms are trapped, they glow. You can see the fluorescence from atoms in kind of a cloud,” Lin said. “That's just one of the most amazing parts. On top of that, we're able to move the atoms by moving a magnet near the trap.”

Normally, Lin would have to wait until a master’s or Ph.D. program to interact one-on-one with the building blocks of the universe. But in the Quantum Engineering Laboratory, undergraduates get to learn what it’s like to work with state-of-the-art quantum systems.

“We are creating a first-in-the-nation undergraduate program in quantum engineering,” said Asst. Prof. Alex High, who designed the course along with Asst. Prof. Hannes Bernien. “It seemed natural to develop a lab course that reflects the expertise of our impressive faculty and PME’s strengths in different quantum experiments.”

The class, which debuted this past Winter Quarter, helped molecular engineering major and fourth-year College student, Allie Weary decide to change her studies from the chemistry track to the quantum track.

“At times, it seems like all the cool chemistry has been done,” Weary said. “In quantum, there's all the cool quantum still left to do.”

Meeting Alice and Bob

Weary’s “aha” moment came when she created a quantum random number generator.

She had, of course, learned in her studies about quantum cryptography. She had gone through the lessons about how to use randomly generated numbers to generate an uncrackable, unhackable message from party A to party B—from Alice to Bob, in cryptography shorthand. And she knew how to use the quantum aspects of single photons to generate truly random numbers.

She knew it all, in theory.

“You hear about Alice and Bob, but you've never seen Alice and Bob,” Weary said.

That changed when Weary and her lab partner did it themselves, creating photonic qubits that they then used to send encrypted messages back and forth. It clicked.

“We are doing things with all the math that I've been learning about for the past three years,” she said.

One of Weary’s classmates, fourth-year Addison NewRingeisen, a molecular engineering and economics double-major, shared that wonder.

“It's night and day. To actually see something and build with your hands and transmit a message of your own is so much different than learning about it in a theoretical context,” NewRingeisen said. “I don't think it fully clicks until you have the opportunity to use your hands and see it take place in real life.”

This was exactly the intent of the course.

Putting the pieces together

“You have to find the right pieces—and the right people—to put something like this together,” said Prof. Aashish Clerk, who envisioned the course as part of a new quantum track for UChicago undergraduates. “We had no template, but we knew we had an opportunity to build something at PME that was completely new and innovative.”

When High joined PME six years ago, he was tasked with helping design the undergraduate curriculum for the quantum track. A lab course was a long-term—but vital—goal. When Bernien joined PME a few years later, High found a “like-minded” partner to design the experiments and develop the lab space.

The space and cutting-edge hardware they organized also is used for innovative PME educational outreach programs such as the weeklong high-school program Quantum Quickstart and TeachQuantum, which trains teachers from South Side Chicago high schools how to teach their own students about quantum concepts and technologies.

But the course for undergrads was still a major goal. High and Bernien needed to find a teacher.

"We were lucky that we found Danyel Cavazos, who is extremely good experimentally but also extremely good at teaching," Bernien said. “Danyel is enthusiastic about the material and conveys that enthusiasm to the students.”

Expanding the portfolio

The course currently offers students a chance to develop hands-on experience on three different state-of-the-art quantum engineering platforms: entangled photons, ultracold atoms and nitrogen-vacancy centers.

“We are providing our students with experience in a broad range of different systems,” Bernien said.

In the first three weeks, an entangled photon source teaches the basics of making photonic qubits, violating Bell inequalities and sending quantum secure messages. The magneto-optical trap and the glowing clouds that captivated Lin teach about laser-cooling. And in the third experiment block, students learn about quantum sensing by using a diamond with spin defects to detect magnetic fields.

These all reflect cutting-edge research done by PME faculty.

“The idea in the future is to keep expanding the portfolio of experiments that we have,” Cavazos said. “We want to continue to take advantage of the different research projects that principal investigators lead at PME and then incorporate them into this class.”

The course has been an eye-opener for students. Weary switched her studies to focus on quantum. Lin is currently an undergraduate researcher working in PME Professor Allison Squires’ lab. And NewRingeisen hopes to take this experience into industry, first using his double major in Molecular Engineering and Economics to enter grad school, then the startup world.

“This experience at PME in quantum research as an undergrad has given me an edge during the application process and also been a nice culminating class to bring all of the concepts I've learned in the past three years together,” NewRingeisen said.

—Adapted from an article first published by the Pritzker School of Molecular Engineering.