Institute Professor Mildred “Millie” Dresselhaus profoundly changed our comprehension of matter—the tangible substance of the universe that possesses mass and occupies space. During her 57-year tenure at MIT, Dresselhaus played a crucial role in motivating individuals to leverage this newfound knowledge to address some of the planet’s most pressing issues, ranging from generating clean energy to combating cancer. Though she became an emerita professor in 2007, Dresselhaus, who instructed in electrical engineering and physics, stayed actively engaged in research and all facets of MIT life until her passing in 2017. She would have celebrated her 95th birthday this November.
Renowned as the “Queen of Carbon,” Dresselhaus was frequently celebrated for her groundbreaking work with one of nature’s most plentiful and adaptable materials. Due to her unquenchable curiosity about the world and her nearly sixty-year career as a scientific pioneer, we owe her substantial advancements in our understanding of carbon’s diverse forms and the companions it interacts with. In the early stages of her career, Dresselhaus utilized a then-novel technology—laser light—to delve into the intricate nature of carbon. She worked to differentiate how, for instance, flat sheets of carbon atoms behave distinctively compared to three-dimensional carbon crystals, particularly under the influence of heat, electrons, or magnetic fields. Later, she foresaw the existence of what we now recognize as carbon nanotubes, tiny cylinders created from rolled-up sheets of carbon atoms that can be exceptionally efficient at conducting electricity.
Building upon Dresselhaus’s extensive foundational research, scientists and engineers have achieved tremendous progress at the nanoscale, with structures measuring one hundred-thousandth the width of a human hair. Spherical carbon “buckyballs,” cylindrical carbon nanotubes, and two-dimensional carbon sheets known as graphene have been employed for energy storage, medical studies, building materials, and ultra-thin electronics, among many other uses. Presently, these carbon structures are still being refined for numerous innovative applications that often seem to emerge from the realm of science fiction, such as ultrafast quantum computers, efficient desalination technologies, and quantum dots with roles in biosensing and drug delivery. For her contributions, she received—among other accolades—the Kavli Prize in Nanoscience, the National Medal of Science, and the Presidential Medal of Freedom, the highest civilian honor awarded by the United States government.
However, her path to MIT, and to a position of global influence in solid-state physics, was a remarkable one. Born in Brooklyn, New York, to immigrant parents in 1930, Dresselhaus matured during an era when women were seldom welcomed as scientists or encouraged to pursue technical careers. Nevertheless, she benefited from several pivotal mentors who recognized her promise and took proactive steps to nurture a brilliant young intellect.
One such mentor was Enrico Fermi, the esteemed Italian-born nuclear physicist who was instrumental in the Manhattan Project and concluded his career as a physics professor at the University of Chicago. After earning a solo Nobel Prize in 1938 (for his work on induced radioactivity) and subsequently fleeing the Nazi regime with his Jewish spouse, Laura, Fermi emigrated to America. The story of how Fermi impacted a burgeoning Millie Dresselhaus—and, indirectly, countless students who would learn under her guidance—demonstrates how imparting knowledge to the next generation of scientists and engineers can yield enduring benefits.
In 1953, as the nuclear age was firmly established and the Cold War escalated, Dresselhaus found herself, at 22, among the new graduate students in the University of Chicago’s prestigious physics department. Although some researchers who had been involved in the Manhattan Project had since departed for various opportunities, many luminaries remained. In addition to the famous Enrico Fermi, other notable faculty included Nobel laureates Harold Urey and Maria Goeppert Mayer (with whom Dresselhaus resided for about a year as a boarder) along with physicist Leona Woods, the sole woman present during the historic 1942 fission demonstration on one of the university’s squash courts.
The university’s physics program was relatively small at that time: Dresselhaus secured a place as one of just about a dozen new graduate students that year. It turns out she was also the only female student in the department. Despite holding a master’s degree in physics from Radcliffe College and a Fulbright fellowship at the University of Cambridge, she did not feel completely prepared as she embarked on her PhD journey. And so, at the onset of her doctoral studies, she stumbled upon a trove of old exams, working through the problems both forward and backward until she felt ready.
Despite this additional practice, the coursework for first-year PhD students was grueling—so grueling that around three-quarters of all incoming physics students eventually withdrew from the program. However, Dresselhaus’s rapport with Fermi would provide an unexpected advantage.
She first encountered the unyielding scientist—who achieved significant advancements not only in the development of the atomic bomb but also in particle physics post-war—as a student in his quantum mechanics class. Through that class, Dresselhaus became acquainted with his teaching style, which she remembered as patient, inspirational, and enlightening. With a slow, deliberate, accented voice that Dresselhaus described as “halting,” Fermi expertly broke down complex topics so that all attendees could grasp them. Brilliant in both theoretical and experimental realms, he took pleasure in distilling concepts to their essence, and unlike more impatient professors engrossed in their own research, Fermi relished the opportunity to clarify physical concepts by explaining them to others. For this, he undeniably had a gift; according to Dresselhaus, thanks to the clarity with which he presented the intricacies of quantum mechanics, “any youngster could believe, upon hearing the lecture, that they understood every word.”
A key factor in the exceptional scientist’s clarity was his prohibition on note-taking. Fermi insisted on full engagement, preparing and distributing handwritten notes prior to his lectures, to prevent students from being tempted to reach for their pens or slide rules. “What was so impressive and astounding about it is that the lectures were incredibly captivating, no matter the topic,” Dresselhaus recounted in a 2001 interview.
Then came the homework, which was invariably challenging but enlightening once you solved it. At the conclusion of every class, Fermi would propose a seemingly straightforward problem to be tackled as an exercise before the next lecture. These included questions like: Why is the sky blue? Why do the sun and stars produce spectra of light? And, famously, how many piano tuners exist in Chicago? “It seemed simple until you returned home,” Dresselhaus mentioned in 2012, while receiving the Enrico Fermi Award, a lifetime achievement honor bestowed by the US Department of Energy. These types of inquiries became known collectively as “Fermi problems” and are now taught in schools worldwide, from kindergarten to graduate-level courses, as examples of how to estimate and triangulate in search of an answer, even when all the relevant—and seemingly essential—parameters are not known. When Dresselhaus was grappling with such problems, all she knew was they were due by the next session, just a day or two away, and required significant effort. “I believe we learned a great deal from him regarding problem formulation in physics, thinking about physics, problem-solving techniques, and generating our own problems,” she stated.
Indeed, throughout her career, Dresselhaus acknowledged Fermi as having taught her to “think like a physicist.” A fundamental idea behind the Fermi system, she often expressed, was the concept of single-authorship research: Graduate students were expected to conceive, execute, and publish their thesis work largely on their own, without the direct assistance of a senior faculty member. This compelled them to collaborate with others to develop a holistic understanding of physics, which they could then apply to independently developed research topics.
Fermi’s engagement with students extended beyond the classroom. He was recognized for his regular interactions with young individuals and was one of the few senior faculty members who consistently included students in his personal sphere. “It was not beneath him to relate freely with students and treat them as equals,” stated Jay Orear, a career physicist and graduate student of Fermi’s, in a collection of remembrances about his mentor. “In fact, I believe he appreciated young physics students more than some of his older colleagues.”
For Dresselhaus, this integration began quite literally on her path to school. She and Fermi lived in the same neighborhood and were both early risers who walked down Ellis Avenue to the lab each day. “I had him for class first thing in the morning. And on my way, as I walked to school, I would see him. He would cross the street and accompany me,” Dresselhaus recalled in a 2007 oral history interview. “That was just a display of friendliness, and it made a lasting impression on me.”
Whenever they encountered each other, Fermi would always dictate the discussion topic and never failed to invigorate and inspire her. “I was a very introverted youngster and would not have dreamed of proposing topics to Enrico Fermi,” she told MIT Alumni News in 2013. “He would frequently pose questions about ‘What if this and this and this were true? What if we could create this—would it be fascinating, and what could we uncover?’”
Fermi and his spouse, Laura, were well-known for hosting monthly dinners at their residence, with dancing to follow—and his students were always included. “Fermi particularly enjoyed young individuals,” noted Harold Agnew, a veteran physicist and one of his graduate students, in a remembrance published after Fermi’s passing. “The top floor of his Chicago home featured a spacious room where he invited students for square dancing.”
“I have fond memories of those dinners,” Dresselhaus mentioned in 2012. “Laura Fermi was an excellent Italian cook.” However, beyond the food, she stated, “it was the warmth and friendliness in that household that truly enhanced our enjoyment of physics—it was something more.” That “something more” inspired Dresselhaus later in her career to offer her own students at MIT a familial atmosphere in the lab, during group lunches, and at events in her home, where the distinctions between student and professor were somewhat blurred, allowing kindred spirits to enjoy one another’s company.
Dresselhaus’s relationship with Fermi lasted only a year. He had been diagnosed with terminal stomach cancer, likely a consequence of his earlier radiation exposure, and passed away on November 28, 1954. Nevertheless, he left an indelible impact that influenced her for the remainder of her life, instilling in her a commitment to public service and guiding her approach to mentoring her own students.
“The most crucial thing that young individuals require is the confidence that they can succeed. That’s my primary focus.”
“Fermi had an incredibly profound effect on the teaching of physics in the United States, and our graduate programs … are largely modeled after his manner of teaching,” Dresselhaus stated in 2001. She later added, “From him, I learned that while we do not need to lead in every domain, we can utilize our comprehension to identify connections that others might overlook.”
The extensive physical and scientific knowledge that Dresselhaus cultivated through Fermi’s teaching method benefited her in significant ways throughout her career. It proved invaluable at various times when she needed to make pivotal shifts in direction, even with minimal background in the fields to which she turned. And she relied on it as a leader of national initiatives with a varied array of stakeholders.
Yet perhaps the most remarkable lesson Dresselhaus learned from her mentor was an understanding of the qualities needed to be an exceptional teacher and advocate. “The essential thing that young individuals require is the confidence that they can succeed,” she articulated in 2012. “That’s what I concentrate on. When I mentor students, I ensure they are capable of defining and solving their own challenges. I am available to assist them if they come to me for guidance. Additionally, I guarantee they receive the necessary training for their next career step.”
By all accounts, she more than accomplished this goal. At MIT, she became a cherished professor who encouraged her students to excel and provided support, both substantial and minor, to ensure high achievement—assisting students in networking for job opportunities, inviting any student without a place to go for Thanksgiving dinner, and leading an entire recitation section for a promising engineering student who required help catching up in solid-state physics. She remarked, “I always sensed that Fermi and Rosalyn [Yalow, her undergraduate mentor at Hunter College] were invested in my career, and I strive to offer the same level of concern for my students.”
In the eight years since Dresselhaus’s passing, advancements initiated by her colleagues have left an imprint of her research—and have started branching off into increasingly captivating avenues. For instance, graphene continues to be one of the most discussed topics in science. Back in the early and mid-2010s, Dresselhaus worked on what she and her team referred to as “misoriented graphene.” She and others speculated that by twisting sheets of graphene so that their honeycomb structures are slightly offset when overlaid, researchers might introduce “interesting patterns” that could yield beneficial properties. In 2018, Dresselhaus’s MIT colleague Pablo Jarillo-Herrero turned this idea into reality: He and others discovered that when two sheets of graphene are combined into a superlattice, aligned at a “magic angle” of 1.1 degrees, the system can switch between superconducting and insulating states. This breakthrough was celebrated as a significant discovery and marked the inception of a subfield now referred to as “twistronics.” Physics World designated it as Breakthrough of the Year.
In 2018, MIT unveiled a state-of-the-art nanoscience and nanotechnology research center at the heart of the campus. The $400 million MIT.nano project had been a long time in the making; although Dresselhaus did not witness the grand opening, she eagerly anticipated its completion and the dawn of a new era of nanoscale explorations at the Institute, which would aim to broaden mankind’s grasp of physics, chemistry, materials science, energy, biology, and much more. In her later years, Dresselhaus regarded MIT.nano as an extension of her legacy.
In late 2019, the courtyard between the Institute’s Infinite Corridor and the southern side of the MIT.nano facility was dedicated in her honor. Named the Improbability Walk, the space symbolizes Dresselhaus’s astonishing rise to international recognition from her modest beginnings in Depression-era New York. It also serves as a reminder for those who might act as mentors to invest time in building relationships with younger colleagues and students, just as Enrico Fermi did with Dresselhaus and Dresselhaus did with so many at MIT. For as unlikely as it may seem, an encouraging word from a mentor can greatly enhance a young scientist’s career trajectory.
Similar to Fermi before her, Dresselhaus was passionately devoted to giving back—to students, her research community, and society in general. Throughout her 86-plus years, she freely shared her time, intellect, energy, love, and enthusiasm. In one of her final interviews, the Queen of Carbon issued a stirring invitation. “We require fresh science and new ideas, and there’s ample space for young people to join and forge careers discovering those new ideas,” she proclaimed. “This lane of life is incredibly fascinating. Come and join me!”
Adapted from Carbon Queen: The Remarkable Life of Nanoscience Pioneer Mildred Dresselhaus, by Maia Weinstock (MIT Press). Copyright 2022. Reprinted with permission.
