Research & Innovation

Igor Pikovski Receives $777K Sloan Partnership Grant for First-Ever Experiments of the Gravity-Quantum Interface

The assistant professor of physics has a hunger for exploring nature’s ‘big questions’

Quantum gravity — which combines Einstein’s gravity with the principles of quantum mechanics — has long been relegated to the realm of the theoretical. And while the smartest physicists of the last century-plus have been attempting to combine the two theories, there remains no accepted solution. In response, Igor Pikovski, an assistant professor of physics at Stevens Institute of Technology, is taking a different approach: looking for experimental evidence with quantum technologies. His team was recently awarded a grant totaling $4 million, with $776,668 allotted to Stevens, to develop the first experiments where quantum mechanics and general relativity both have measurable effects. His proposed experiments, once thought impossible, have the potential to bridge the understanding of these seemingly incompatible foundations of physics.

Funded through a partnership of the Gordon and Betty Moore Foundation, the Simons Foundation, the Alfred P. Sloan Foundation and the John Templeton Foundation, the five-year research project is led by the University of Colorado Boulder in collaboration with Stevens Institute of Technology and the University of California Berkeley. The experiments will be performed in Boulder and Berkeley by Jun Ye and Shimon Kolkowitz, leaders in atomic clock development, while the Pikovski research group at Stevens will develop the theoretical ideas.

Professional headshot of Igor PikovskiIgor Pikovski, Assistant Professor, Department of Physics

An 'impossible' experiment

One of the biggest mysteries of modern physics is that there exist two established and tested theories that work well: Einstein’s theory of relativity, and quantum theory. The problem is, by current understanding, the theories seem incompatible.

Pikovski explained, “Einstein's theory of gravity, which has been tested so many times, was developed 100 years ago. And that's a wonderful theory and it works. And then we have quantum theory, which was made to describe the atomic world, particles and so forth. And that also works very well. Now, the problem is, they don't match, they don't fit together. We have no idea even how to mathematically combine them. Nothing works.”

He admits he initially thought the experimental study of quantum gravity was an impossible order. This journey began for him, as often happens in science, as a happy accident.

“As a student, I was exploring what type of research one could do. And of course I knew there is the big problem of quantum gravity, and everybody wants to work on it and solve it. It's very hard, and I ended up wanting to go into this field,” Pikovski related. “I accidentally met an experimental physicist [Dirk Bouwmeester at University of California Santa Barbara] who works in the lab, and he told me something very exciting. 

“He said, Look, we’re trying to design experiments to try and address these questions.

“I told him, This is not possible. Everybody knows it’s not possible, that we would need to fly to a black hole in order to do such experiments.

“He said, No, no, no. There are new ideas out there, and it’s actually possible.”

Since that initial interaction, Pikovski’s goal has been to think of new ways to test this interface. While he describes the typical theoretical physicist’s lab as “just our offices and our blackboard,” he is excited to advance the theoretical to the experimental.

In this project, Pikovski and team will develop ultra-precise atomic clocks to perform novel tests of foundational general relativity principles and examine the intersection of quantum mechanics and general relativity. The resulting “tabletop” experiments — conducted at a scale typical of a university research lab — hold the potential to advance the foundational principles of both quantum mechanics and general relativity.

‘At the start of something new’

Pikovski is fascinated by the mysteries of quantum physics and what makes it special.

“Our work specifically is very blue-sky research…it's not driven by concrete problems that we might have, or we need a solution to solve something. It's rather more trying to understand what nature is about and why it behaves the way it does and uncover new laws about it,” he said.

We have many, many big questions still. We have hardly even scratched the surface of what we understand in the universe, which is why it’s so exciting.
Igor PikovskiAssistant Professor, Department of Physics

“So it's really just about a curiosity-driven approach to big questions in nature. Surprisingly, we have many, many big questions still. We have hardly even scratched the surface of what we understand in the universe, which is why it’s so exciting.”

Among the open questions in quantum physics, scientists still don't know how quantum phenomena might matter when gravity comes into play. “Another big part of physics,” Pikovski remarked, “we don't even fully know what is exactly special about quantum phenomena.”

Although he cannot yet predict practical applications of the tabletop experiments he is designing with this mega-grant, Pikovski pointed out that deep understanding and learning “for the sake of learning” has historically led to many new technological applications, such as the laser and quantum computing.

“Quantum physics has become popular in the last decade or so because people figured out that we can build quantum information devices with it, so we can build quantum computers with it, quantum cryptography. And that took 100 years!” he said. “So we are now at the start of something new, where we can enable novel opportunities and technologies using quantum physics, but it's just from a deeper understanding of what's actually happening there.” 

His research will focus on atomic clocks, which are perhaps the most precise instruments ever built. They are foundational for many technologies, such as global positioning systems (GPS).

“We want to show that [atomic clocks] can also push into the gravity-quantum realm,” he explained.

A photo of the quantum clock laboratory setupThe atomic clock in the experimental laboratory: The glowing blue dots pictured here are ultra-cold strontium atoms in a vacuum chamber, cooled close to absolute zero temperature. These atoms are interrogated by a laser to serve as atomic clocks.CREDIT: Shimon Kolkowitz

Students bring creativity to ‘big open questions’ 

Pikovski relates to his students who are passionate about what he calls the “big open questions” of nature. Often the emphasis in academia is practical, but Pikovski has not forgotten his sense of wonder, and he encourages these qualities in his students as well.

As quantum physics is revolutionizing industry today, students of physics can look forward to practical applications of their studies. While Pikovski is excited by these ever-growing possibilities, he admits that “the true answer [of why I research] is really just because we are curious. I think if you really want to find out what the world is made of, it's actually really well-suited for students because these kinds of big questions are what usually excite students.”

Pikovski works with undergraduates, graduates, and even high school students in the lab and in the classroom. Just as they learn from him, he also learns from his students.

“It's always very rewarding because they come with a fresh perspective. They have ideas that are maybe new. And that's exactly what one needs in this kind of field, because we want to be open-minded about how we would approach things,” he said.

‘Space to do exciting research’

Pikovski feels that Stevens offers a supportive path for early-career academics to find their voice and establish their research. He says that both his colleagues and his students are “extremely gifted.”

“Stevens is very open to new initiatives, new ideas, and just giving space to do exciting research. I appreciate it very much, and I enjoy this place mostly for that reason,” he said.

We are now at the start of something new, where we can enable novel opportunities and technologies using quantum physics.
Igor PikovskiAssistant Professor, Department of Physics

With the students, colleagues, and resources in hand that he needs, Pikovski is eager to keep asking — and hopefully even answer — some big questions.

“It will be hard, but [we aim] to outline what experiments one can think of with quantum technologies, and somehow find new cases for them in order to really see how gravity and quantum physics intertwine. That's our big goal. I think there are some very exciting approaches that one can find…to show what type of experiments we could potentially do to at least answer some small aspects of this big question.”

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