Current Position
Research Scientist - Google AI Quantum
Research Area
Quantum Information Physics
Research Type
Experimentalist
Education
Ph.D. 2025, Yale University
Advisor
Robert Schoelkopf
Dissertation Title
Controlling and protecting quantum information in superconducting oscillators
Dissertation Abstract
Modern quantum experiments allow the precise manipulation and measurement of many-body quantum states, pushing quantum mechanics from a testable theory to a utilizable technology. The central promise of these systems is to process quantum information for exponential advantages in computing, sensing, and communication. An interesting way to achieve such a processor is to store and manipulate quantum information in the continuous-variable (bosonic) phase space of light. Since photons in free-space do not talk to each other, such an approach necessarily requires the introduction of nonlinearity through strong light-matter couplings. However, since all matter is lossy, this inevitably introduces a trade-off between the speed of control and the inherited decoherence of the light.
This thesis achieves controllable bosonic systems by trapping microwave light in the standing waves of a superconducting oscillator, and making it interact with Josephson junction-based nonlinearities. I first demonstrate novel ways to exchange single photons between two oscillators through carefully constructed driven nonlinearities, achieving several orders of magnitude higher fidelity than previously possible. I then introduce ways to utilize such a high-fidelity coupler to dynamically couple light and matter, in a way that breaks the trade-off between universal control and inherited decoherence. Finally, I theoretically show how such universal control can autonomously protect any appropriate error-correction code in the bosonic mode, against a full Lindbladian error channel. Together, this thesis provides a promising path towards fault-tolerant bosonic quantum processors.