PQI Distinguished Seminar - Cindy Regal

Motional Kerr-Cat States of an Atom in an Optical Tweezer Abstract Schrödinger cat states enable quantum information to be encoded in a superposition of classically distinct states, and constitute a powerful resource for quantum computing and enhanced metrology. Creating such states in the phase space of an oscillator requires a nonlinearity, typically inherited from an auxiliary degree of freedom such as atomic spin or a Josephson junction. Neutral atoms trapped in reconfigurable optical tweezer arrays - one leading platform for quantum science and computing - provide an intrinsic nonlinearity via the motion of a single atom in a tightly focused trap. However, this self-Kerr mechanism has not previously been exploited for cat-state generation, and remains largely unexplored as a resource for motional-state control. We realize Schrödinger cat states in the quantized motion of a single neutral atom trapped in an optical tweezer. By modulating the depth and position, we demonstrate parity control of both Kerr-cat and Fock states alongside tunable nonlinearity, establishing a spin- and species-independent framework for controlling motion in tweezers. We further show that the cat-state encoding is intrinsically robust against trap-frequency fluctuations that otherwise limit the fidelity of direct Fock-state transitions. These results establish Kerr-based control of neutral-atom motion as a new paradigm for bosonic-state engineering in optical tweezers. Bio Cindy Regal is a Professor of Physics at the University of Colorado, Boulder and the Baur-SPIE Chair at JILA. She completed her PhD at CU Boulder in 2006, followed by postdoctoral research at the Californian Institute of Technology as a Millikan Fellow. In her PhD she studied strongly interacting fermionic pairs in an ultracold atomic gas. After her postdoctoral work in quantum optics, she joined the faculty at the University of Colorado in 2010. Her research group has focused on accessing novel regimes of quantu