Caltech undergraduate Yiyi Cai is set to join the 2025 cohort of Gates Cambridge Scholars at the University of Cambridge in the upcoming year. Originally from Beijing, Cai moved to the United States when she began high school, and she will be pursuing an MPhil in advanced computer science.
Cai’s specific focus lies in quantum computing, a domain she first encountered during her high school years. “Back then, I really had no clue how to begin or the resources necessary to do so,” she states. “At that point, I was mostly focused on becoming a software engineer. I was passionate about computer programming.”
“Upon my arrival at Caltech, I realized this was the hub for quantum computing and quantum information. This is essentially where it originated,” Cai reflects. “I actively sought out avenues to dive into this field. After my second year, Professor John Preskill [Richard P. Feynman Professor of Theoretical Physics and the Allen V. C. Davis and Lenabelle Davis Leadership Chair of the Institute for Quantum Science and Technology] graciously decided to take me on for a summer internship. I’m very grateful for that opportunity.”
“Simply being at the IQIM [the Institute for Quantum Information and Matter] at Caltech was immensely motivating. Each year, a diverse group of postdoctoral researchers and graduate students joins with a variety of fascinating interests, making them incredible individuals to engage with,” Cai observes. During a SURF (Summer Undergraduate Research Fellowship) in Preskill’s group, Cai delved into the theoretical dimension of quantum information, a niche that merges computer science and physics, examining how quantum mechanics can be utilized to innovate and understand new computing models.
“The core concept of quantum computers revolves around how we can harness quantum mechanical phenomena for computation. In broad terms, it can be viewed as how nature—through quantum mechanics—facilitates computation,” Cai explains. “An intriguing analogy I came across was comparing it to having a bucket of water for simulating fluid mechanics; you could use advanced computations on current machines to model all the water’s movements. However, what if instead of simulating, you utilized the bucket of water itself for the work? Envision that bucket as a quantum computer, where the system’s behavior constitutes the computation itself. That encapsulates the fundamental idea of quantum computing: allowing nature to operate under its physical laws to process information and execute computation—and ideally achieve greater efficiency.”
Cai expresses her excitement about the chance to study at Cambridge, where several new faculty members focused on quantum computing have recently been recruited. “I had planned to initiate a PhD in computer science at Stanford next year, but I will defer for a year to seize the Gates Cambridge opportunity,” Cai clarifies. “I consider myself very fortunate that 2025 coincides with their 25th anniversary, prompting them to select 25 additional scholars.”
Cai envisions using this year to investigate various subjects so that upon her return to the United States for her PhD at Stanford, she will have clearer goals. At Cambridge, she will be among 99 other scholars globally, chosen for their exceptional intellectual prowess, dedication to enhancing others’ lives, and potential for leadership. The Gates Cambridge Scholarship program was initiated in 2000 by the Bill and Melinda Gates Foundation, providing full scholarships for graduate studies across all disciplines available at the University of Cambridge.