“If I ever write a memoir, I think I’ll call it All the Right Decisions for All the Wrong Reasons,” says Bharath Kannan SM ’18, PhD ’22, cofounder and CEO of Atlantic Quantum, a Cambridge-based startup working to build a scalable quantum computer. “In my life, many pivotal choices stemmed from trusting my intuition, rather than careful reasoning, and more often than not, they’ve led to positive outcomes.”
One of those intuitive choices was to come to MIT for graduate school. The son of immigrant parents from Chennai, India, Kannan was born and raised in New Jersey. He studied physics with a special focus on computer science and quantum computing at Rutgers University, where he finished his bachelor’s degree in three years. “I always knew I would do a PhD,” says Kannan. “But what convinced me to come [to MIT] was the campus visit. As soon as I saw the place I said, ‘This is it.’”
Shortly after arriving on campus to start his graduate studies in fall 2016, he contacted Professor William D. Oliver, the director of the MIT Center for Quantum Engineering. “Will was just forming a laboratory to work on superconducting quantum hardware. He said I could be part of the first cohort. Once again, without really exploring the many alternative quantum platforms here at MIT, I trusted my gut and said I was in.”
The idea of quantum computing was first launched in the 1980s. “The basic information unit of a classical computer, the bit, works in a binary language. It is either a one or a zero,” explains Kanan. “And because of the way information is encoded, classical computers struggle to simulate certain complex quantum mechanical systems. The fundamental computational element in a quantum computer is a quantum bit, or qubit, which can exist in a so-called ‘quantum superposition,’ a state where the qubit is in a combination of 0 and 1. This difference in the way information is encoded is one of the key differences between quantum and classical computers. A processor built using these principles of quantum mechanics, in theory, could enable a powerful new class of computers that can solve certain problems of interest today’s computer cannot.”
At MIT, Kannan worked with the Engineering Quantum Systems Group to help develop a new architecture to connect quantum processors. Following his graduation in July 2022, he and six other MIT colleagues founded Atlantic Quantum. The startup raised $9 million, much of it from The Engine, the venture capital firm spun out of MIT in 2016 to focus on “Tough Tech.”
“I never intended to start or work at a startup,” says Kannan. “I’m the child of immigrants, raised to study hard, get a good job, and stick with it. But there was something about staying connected to MIT and its awesome community that drew me in. It was a shot at building something big from the ground up. So, once again, I found myself going with my gut rather than a by-the-book plan.”
It will take many years of engineering before anyone builds a useful fault-tolerant quantum computer. But we believe our technology has one of the best chances of building a viable quantum computer.
The road to building a viable quantum computer is strewn with hurdles. At Atlantic Quantum, Kannan and his colleagues are focusing on the biggest two. The first hurdle is the error rate. Physical errors occur in qubits roughly once in every 100 operations. A second problem is scale. A viable quantum computer would require millions of qubits, each with its own microprocessor, to generate the complex signals necessary for operation. The sheer volume of hardware makes even the thought of a functional quantum computer hard to imagine.
“To make matters even more complicated, when you try to simplify the control signal system, you tend to increase the error rate,” says Kannan. “And when you try to reduce the error rate, you typically make the circuitry and signals even more complicated, which requires even more sophisticated hardware. Approaching these problems one at a time can feel like a zero-sum game. So, we decided to approach them both at once.”
Atlantic Quantum’s solution to the joint problem is based on a new type of qubit—the fluxonium qubit—which operates at a much lower frequency than the type used by most companies. This lower frequency is akin to putting headphones on the qubit: The noise is still there, but the qubit “hears” less of it. This translates into fewer errors. It also reduces the complexity and cost of electronics needed to operate the system. “It will take many years of engineering before anyone builds a useful fault-tolerant quantum computer,” says Kannan, who was named one of MIT Tech Review’s 35 Innovators Under 35 in 2023. “But we believe our technology has one of the best chances of building a viable quantum computer.”
Photo: Nana Kusi Minkah.
Interested in learning more about quantum? Register now for the November 15 MIT Alumni Forum, “Quantum: the Hope, the Hype, and the Glory,” to hear about modern applications and the future promise of quantum technologies from MIT professor Peter H. Fisher, an expert in dark matter and particle physics.