Meet Susanna Todaro

Advisor: Isaac Chuang

Institution: Massachusetts Institute of Technology

Bio:  Dr. Susanna Todaro is an IC Postdoctoral Fellow at the Massachusetts Institute of Technology. She received her Ph.D. in Physics in 2020 from the University of Colorado in Boulder, where she studied techniques for scaling up trapped-ion quantum computing systems in the Ion Storage Group at the National Institute of Standards and Technology. She currently continues to study trapped ion quantum computing in the lab of Isaac Chuang at MIT, closely collaborating with researchers at MIT-Lincoln Laboratory. Her current research focuses on novel qubit encodings in trapped ion systems.

Abstract:

Trapped-ion quantum information experiments have generally encoded the qubit either between sublevels of the ground electronic state or between the ground state and a long-lived metastable state. These qubit encodings have enabled exciting results, including high-fidelity two-qubit gates and the implementation of rudimentary quantum algorithms on trapped-ion quantum computers.  However, many proposals for scaling to larger trapped-ion systems rely on the use of a second ion species as a sympathetic coolant or an ancilla, which introduces substantial increased experimental complexity.

I am investigating another category of qubits: the metastable qubit, in which the qubit is encoded in sublevels of a long-lived metastable state. Qubits in this metastable manifold would be largely insensitive to scattered laser light addressing a neighboring qubit in the ground state manifold and vice versa. This could enable quasi-dual species operation, in which many of the applications of dual-species ion trapping, such as sympathetic cooling or ancilla qubits in quantum error correcting codes, could be implemented in a chain of identical ions. This would improve the vibrational mode structure and potentially reduce experimental complexity. I am towards metastable qubit operations using sublevels of the 2D5/2 state of Sr+ and Ba+ ions, which have accessible visible and infrared transition wavelengths and an appropriate atomic structure for encoding quantum information in a metastable qubit.