image of waves and particles and quantum equations

Making quantum waves

Tulane’s emphasis on bringing the best minds from the widest fields together for innovation and discovery is driving startling breakthroughs in one of the world’s most fascinating and consequential fields.

It may be the most important area of science you’ve never heard of.

In 1925, researchers at the University of Göttingen first used the term “quantum mechanics” to describe interconnected phenomena they found in the study of atoms and the study of light. One century later, quantum mechanics still fascinates researchers as they attempt to learn more about what happens to very, very small particles that have huge implications for all of us.

While it is a field little understood by non-scientists, absent the last century of research and discoveries in quantum mechanics, we would not have the semiconductors ubiquitous in electronics such as iPhones and MRI machines or the LEDs used in televisions, headlights and lightbulbs — to name just a few advancements.

To celebrate 100 years of quantum mechanics and broaden public understanding of the field’s importance, the U.N. General Assembly declared 2025 the UNESCO International Year of Quantum Science and Technology.

It is an anniversary Tulane embraces. From creating faster computers to developing materials for solar panels to imaging archaeological finds, quantum research takes on many forms at Tulane, reaching across disciplines to include chemistry, computer science and more.

“Quantum physics is all around us,” said Lev Kaplan, professor and engineering physics advisor in the School of Science and Engineering (SSE). “Some of the most exciting research happens when two people are working in adjacent fields. Maybe both have to do with quantum mechanics in different ways, but when they bring together their expertise, you can do something collaboratively that neither research group would be able to do on its own.”

“Some of the most exciting research happens when two people are working in adjacent fields. When they bring together their expertise, you can do something collaboratively that neither research group would be able to do on its own.”

Lev Kaplan, engineering physics advisor and professor in the School of Science and Engineering

portrait of Lev Kaplan, wearing a blue shirt and glasses and standing against a green background

Lev Kaplan

For example, Denys Bondar and Ryan Glasser, both associate professors in SSE, have published a number of studies together. Glasser’s research focuses mainly on quantum computing, while Bondar’s focuses on a field called non-linear optics, but the overlap in their work has been incredibly fruitful.

“I would not have accomplished some of the things I have without being here,” said Bondar. “It’s directly connected to being here and meeting my colleagues.”

Modern alchemy

Bondar describes his research as “alchemy as a quantum problem,” hearkening back to a time when people were trying to turn lead into gold.

Although it is theoretically possible to turn lead into gold, it is completely impractical. Bondar instead approaches it as an optical problem: How do you make a material look like another material or behave like another material?

Making some material mimic another — such as a cheaper material in place of an expensive one — can help scientists conduct research without fear of wasting resources. While this practice is currently used for research rather than commercial applications, it could lead to methods for producing better computers at a lower cost, for example, or characterizing new materials, something essential for discovering new drugs.

Bondar and his colleagues use a concept called “quantum control” to accomplish this, which means “you can use something external, like laser light, to make your quantum system do whatever you want,” said Bondar.

portrait of Denys Bondar against an orange background

Denys Bondar

A fundamental part of Bondar’s research is the properties of electrons.

“That’s where the quantum business is coming in, how light interacts, how photons interact with electrons, and how you can change this interaction, how you can steer it to the direction you want,” said Bondar.

Where classical and quantum mechanics meet

One thing quantum researchers are careful about is the distinction between “quantum mechanics” and “classical mechanics.”

Classical mechanics can be observed on the human scale and follows traditional laws of physics, many of which have been known for hundreds, if not thousands, of years. It covers things like Newtonian mechanics, of “for every action, there is an equal and opposite reaction” fame, as well as electromagnetism, which describes electricity, magnets and light.

Quantum mechanics deals instead with the smallest objects in the universe — at the atomic and subatomic levels — and how they interact with each other.

One of the things Kaplan focuses on in his research is where classical and quantum mechanics meet, to see what happens when the behaviors intersect. Kaplan’s hope is to figure out how to use quantum mechanics to make materials — like solar panels, for instance — more effective in different environments, including at higher or lower temperatures.

But at the end of the day, Kaplan, like many quantum researchers, is a theorist. “I don’t actually do experiments in my lab,” he said. “I do a combination of pencil and paper calculations and then back them up by numerical experiment simulations on the computer.”

This is why collaboration is so important to these researchers. Experimentalists and theorists must work together in order to make and prove these groundbreaking discoveries.

Using particles as light

Fred Wietfeldt, by contrast, is an experimentalist.

“Theorists, their job is to make new theories,” said Wietfeldt, professor and chair of the Department of Physics and Engineering Physics. “Experimentalists have to understand the existing theories primarily and then apply them to the experiments.”

portrait of Fred Wietfeldt

Fred Wietfeldt

Wietfeldt’s work is centered around a type of experiment called matter-wave interferometry, which measures phenomena based on how particle waves interfere with each other, like how ocean waves get bigger when they cross paths.

Wietfeldt’s research specifically focuses on neutrons, one of the particles that make up the nucleus of an atom. His experiments depend on treating neutron waves as if they are light waves. One of the most useful applications of these neutron waves is imaging. Neutron wave images work in almost the opposite way X-rays work. “If you want to see heavy material embedded in light material, use X-rays. If you want to see light material embedded in heavy material, you can use neutrons,” Wietfeldt said.

Neutron imaging has been useful for fields like archaeology, which need to be able to image the insides of artifacts without causing damage.

Wietfeldt is the only faculty member studying neutron physics at Tulane, but that has not slowed his work.

“I’ve got a nice lab, I’ve got great students, and I need those things in order to do my work,” he said. “Tulane has been great and really appreciated and facilitated the work I’m doing.”

portrait of Ryan Glasser

Ryan Glasser

A small but mighty department

The Department of Physics and Engineering Physics at Tulane is a small one, compared to many across the country, but, Bondar said, “Size, in our case, doesn’t really matter; the quality does.”

Kaplan argued that the smaller size of Tulane, and of the department, was in fact an asset for better research. “Tulane is small enough, for a research university, that it turns out to be more doable for people in our department to talk all the time to people in chemistry, or biomedical engineering, or mathematics or computer science,” he said.

He added that the university is also supportive of researchers doing this cross-collaboration and following their research wherever it takes them. “I think Tulane has always been great about just allowing people to do what they’re excited about,” said Kaplan.

“The administration and the Office of Research is all really supportive of everything,” said Glasser. “It’s a great place to be.”

It’s not just the administration and leadership that are supportive. Many researchers highlighted the friendly environment in the department among their colleagues.

“It’s a very research-active and friendly environment,” said Adrienn Ruzsinszky, professor of physics.

“Everyone gets along really well,” said Glasser. He particularly enjoys faculty meetings. “I get to see everyone in the same place at the same time!”

portrait of Adrienn Ruzsinszky

Adrienn Ruzsinszky

Imagining new materials

For all its complexity, theorists are working to simplify quantum mechanics through accessible calculations that can be used across fields. Density functional theory is one such attempt, and a successful one at that. It’s been used for everything from developing better lithium-ion batteries to creating new semiconductors.

“Density functional theory is a simplification of quantum mechanics,” said SSE professor John Perdew, one of the world’s most cited physicists and recent winner of the Benjamin Franklin Medal in Physics from the Franklin Institute.

The equations that researchers like Glasser, Bondar and Kaplan use in their work are great for working with a few particles at a time, but they would take too much computing power and time to use for the calculations Perdew performs, which involve many electrons at once.

Ruzsinszky, who also studies density functional theory, compared the way electrons behave to the way bees try not to bump into each other while flying.

“One electron has an impact on all surrounding electrons,” she said.

Density functional theory finds ways to calculate how that many electrons all impact each other while minimizing errors.  The theory is widely used by researchers working to create or study materials from multiple fields.

“The users come from condensed matter physics, from chemistry, from materials science and engineering, from geology,” said Perdew.

Ruzsinszky pointed out that some of the methods she and Perdew create are more useful to some fields than others. “It’s always kind of a balance, to find a method with the potential to be useful.”

portrait of John Perdew

John Perdew

The future of computers

Quantum computing is one of the most widely known uses of quantum physics today. As our technology evolves and we need faster and more powerful computers, researchers hope that quantum computers can fill that need.

While current quantum computers are not at the point technologically where they can be used by most people, researchers like Glasser and ShaoKai Jian, an assistant SSE professor, are researching how to use them effectively when they are.

The field involves the concept of superposition, which allows a quantum system to exist in multiple states at once, to improve computing speed and power. In place of the traditionally smallest unit of digital information — the computer bit — quantum computers use quantum bits, sometimes called qubits.

“In a classical computer, you might tell a bit to go from a zero to a one or vice versa, and there are some errors, but the errors are very small with normal computers,” Glasser said. “When you run a program [on a quantum computer], the quantum bits don’t always do what they should do.”

This conundrum causes the physical limitations that make it difficult to build these computers.

“The quantum state is very susceptible to the environment,” Jian said, noting the importance of keeping the state isolated from its environment to maintain “high fidelity.” This means the quantum system remains in the same state after time has passed. The more quantum bits are near each other in a quantum computer, the more they interact with each other and the more difficult it is to maintain that high fidelity.

portrait of ShaoKai Jian

ShaoKai Jian

Glasser is currently working on how quantum technologies can be used for artificial intelligence, specifically machine learning. One of the major issues with artificial intelligence of any kind right now is that it requires a massive amount of computing power.

“Right now, we’re in this NISQ era, which is noisy, intermediate-scale quantum era,” he said. “They’re noisy, which kind of messes up your calculations that you’re trying to do, and intermediate-scale, where we don’t have quantum computers that have as large a number of quantum bits as we really need to make them particularly useful.”

A second quantum revolution

Even as researchers look to future technologies, some of the fundamental theories of quantum mechanics are still being studied.

“Despite the fact that quantum theory is a century-old theory, the question, ‘What is quantum?’ is still unanswered,” said Bondar.

“Despite the fact that quantum theory is a century-old theory, the question, ‘What is quantum?’ is still unanswered.”

Denys Bondar, associate professor in the School of Science and Engineering

But the field is starting to turn a corner.

“We’re in what people are calling the second quantum revolution right now,” said Glasser.

When the first quantum revolution happened a century ago, scientists were discovering the basics of quantum science for the first time. Now, the field has grown enough to start using that science for practical purposes.

Tulane is ready to lead the way in this second quantum revolution not only because of the researchers and their collaborations but also because of the incredible students studying the field.

“I’ve had not only outstanding graduate students,” said Glasser, “but we’ve had a decent amount of undergraduates work in our group in the past, and they’ve all been really, really outstanding.”

Wietfeldt agrees. Every few years, he teaches a class on neutron science, and “I’ve had three Tulane undergraduate students who, after taking this one class, decided to become neutron scientists,” he said.

As bright young minds join with ever-improving technology, the future of quantum research is filled with endless possibilities.

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