How Harvard Came to the Cutting Edge of Quantum Research

For the past few years, Harvard has publicly been ramping up its investment in quantum science research across the University.

In 2021, the University announced one of the first Ph.D. programs in Quantum Science and Engineering. The following year, it announced a research partnership with Amazon Web Services focused on quantum networking. Months later, in March 2023, Physics professor Mikhail Lukin — whose research is focused on quantum science — received a University Professorship, the highest faculty rank at the University and one of the most prestigious recognitions Harvard awards.

At the heart of Harvard’s rapidly burgeoning quantum research complex is the Harvard Quantum Initiative, which launched six years ago and which is at the center of Harvard’s expansion of research into the field.

The HQI, led by Lukin, Evelyn L. Hu, a professor of Applied Physics and Electrical Engineering, and Physics professor John M. Doyle, describes itself as a “community of researchers with an intense interest in advancing the science and engineering of quantum systems and their applications” on its website.

“We felt a new organization was needed to properly focus resources on an efficient way to launch an effective education and research program in this new intellectual area, while facilitating translation and interaction with industry,” Hu wrote in an emailed statement to The Crimson on behalf of HQI.

Now, six years after the founding of HQI, Harvard’s quantum research has expanded dramatically, bringing with it strong new industry partnerships, cutting edge research, and even helped consolidate funding from the Department of Defense and the federal government.

‘Puts Us On the Map’

When it was first founded in 2018, the HQI was a formalization of existing collaborations within the Physics department.

“The reason why this even exists was that there was quite a bit of collaboration and talking to each other before,” said Susanne F. Yelin, a professor of Physics in residence.

Since then, quantum researchers at Harvard have seen an increase in funding and thus a growth in the research groups, something Yelin said was “really nice.”

“How to pay my students, it's just not my main concern anymore, and this is really nice,” she said. “I started with a group of something like two, three people here at Harvard, and I think right now I have about 20.”

“We are really lucky that there are a lot of people who are so exciting and willing to, as donors, pour a lot of money into this,” she added, pointing to the construction of the HQI’s new building at 60 Oxford Street, which is scheduled to be completed this spring.

Formalizing the collaboration also increases visibility of the institute’s work, according to Yelin.

“It also puts us on the map in the sense of ‘Hello, we are here, we are working on quantum,’” she said.

Liu Mengke, a postdoc at HQI, said the creation of the HQI has benefited postdocs like her. During the annual HQI symposium, professors and postdocs come together to discuss their work, which Liu said is an “opportunity for a good exposure to other PI’s.”

Liu said the symposium is also an opportunity for students and postdocs to “get some advice from those older generations.”

The HQI has also provides other opportunities for researchers to interact with experts in the field, including through a quantum information seminar series organized by Anurag Anshu, a Computer Science professor at the institute.

Indranil Halder, a postdoctoral fellow at HQI, said the featured experts are “much more accessible” through the seminars.

Still, Liu said there are improvements the HQI can make to better serve students.

“HQI is already a good platform for us, but I think there’s a lot more it can do,” she said. “Having a good mix or mingle together between the students from different backgrounds, maybe coffee hours,” she added.

‘The Impossible Happens Much Faster’

Harvard has long received federal funding for its quantum research, including from the Defense Advanced Research Projects Agency, or DARPA, the Department of Defense’s research branch. DARPA has coordinated research across universities with its Optimization with Noisy Intermediate-Scale Quantum devices, or ONISQ, program.

The ONISQ program was born out of the idea that noisy qubits, whose usefulness was believed to be limited to fundamental studies, could extend beyond to impact applications of quantum processors.

Mukund Vengalattore, the ONISQ program manager, said DARPA works towards “forging a community” where scientists work together collaboratively to advance achievement.

“Usually the impossible happens much faster than you think it can,” Vengalattore said.

In 2020, a research team led by Lukin — the University Professor and HQI co-director — and including collaborators from outside Harvard received a grant that would end up totaling nearly $9.5 million dollars from DARPA for work on quantum bits, the basic unit of information in quantum computing.

In classical computing—also known as traditional computing—the basic unit of information is a binary bit. It can represent zero or one—two states—whereas a qubit can represent any amount of states.

Last December, nearly four years later, Lukin’s team created the first quantum circuit with logical quantum bits — an advancement toward fault-tolerant quantum computing and a significant step in reducing the computational errors which quantum computing is prone to.

According to math and theoretical science professor Arthur M. Jaffe, the work at HQI focused on quantum computing is the product of experts from several different fields working together.

“Just as when biology and chemistry came together some years ago to merge into biochemistry, another merging is taking place. Physics, mathematics, and computer science are ripe to converge with the birth of new quantum mathematics which one might call ‘quantum computer science,’” Jaffe wrote in an emailed statement.

Still, there are difficulties with collaborating across fields and bridging the gap between theoretical and experimental quantum science.

Liu, the postdoc, said that she is an experimentalist and while she wants to collaborate with researchers from different backgrounds, there often are challenges in communication.

“Sometimes it’s a little hard to find a common platform so we understand each other's language, but we chat with them a lot,” Liu said.“We got a lot of data and we want them to help us understand,” she added.

Despite the challenges, there are efforts to bridge that gap through class requirements. Liu said one solution to this is “asking experimental students to take some theory classes, and theory students to take some experimental classes.”

‘An Incredibly Exciting Time’

Beyond research, though, HQI also focuses on both working with industry partners and helping professors spin off their own research into private companies — something that researchers say is helpful to expanding research capabilities.

In her emailed statement, Hu, the HQI co-director, wrote that “we believe that translation of the knowledge into real-world applications is also very important, and it’s best done by bridging the cutting-edge research & education done in academic labs with leading industry players.”

While Amazon is perhaps HQI’s most prominent industry partner, the initiative is also working with other companies, including QuEra Computing – a company Lukin co-founded that commercializes quantum computers from the research conducted at Harvard and MIT labs.

Vladan Vuletić, one of QuEra’s co-founders and a MIT professor, said industry partnerships like QuEra are important because they provide stability to researchers who otherwise rely on graduate students.

“We might need better engineering than graduate students can provide, who stay a finite time,” Vuletić said. “Once quantum computing becomes feasible at a larger scale, then at some point, it probably won’t be possible to be done in university labs anymore and would require dedicated people and permanent staff.”

QuEra CEO Alexander Keesling also stressed the importance of having industry professionals.

“Unlike a research lab that has a small number of people that are hyper focused on pushing the boundaries of understanding, here we have a mixture of physicists, engineers of different types, software engineers, electrical engineers,” HE SAID

QuEra is working to expand its industry and scientific partnerships. According to Keesling, QuEra is working with the Lawrence Berkeley National Lab – a federally funded lab at the University of California Berkeley –, BMW, and academics working on machine learning.

But Yan Qi Huan, an HQI graduate fellow and current doctoral student, said while the investment into quantum research is important, people in the field should be careful about “overhyping” quantum science developments.

“I think at the same time amongst some people, there's a fear of overhyping certain companies or certain releases over exaggerating the potential of quantum technologies like quantum computing,” Yan said.

Vengalattore, the DARPA program manager, also emphasized the need for caution in assessing progress in the field.

“We don’t want to go around declaring victory in a premature manner, but victory can take many forms,” Vengalattore said.

In the future, Vuletić sees academic and industry working in tandem to advance quantum computing.

“I see kind of a parallel effort between something that is we take what we know, and we make it bigger and more reliable.” he said. “At the universities, the research goes on to find better systems, better ways of making quantum gates and reliable hardware.”

As researchers and industry experts look to the future of quantum computing, Keesling emphasized the enormous progress in the quantum computing industry.

“This is an incredibly exciting time for the industry, for quantum computing,” he said. “I can tell you that when I started my Ph.D., let alone my undergraduate, the quantum computing industry did not really exist.”