Southwest Quantum Information and Technology

Implementing qudit quantum logic gates on nuclear spins in Strontium-87 atoms

Presenting Author: Sivaprasad Omanakuttan, University of New Mexico CQuIC
Contributing Author(s): Anupam Mitra, Michael J. Martin, Ivan H Deutsch

We study the ability to implement quantum logic gates on states of the I=9/2 nuclear spin in 87Sr, a d=10 dimensional qudit, using quantum optimal control. For one-qudit SU(10) gates through a combination of nuclear spin-resonance and a tensor AC-Stark shift, by solely modulating the phase of a radio-frequency magnetic field, the system is quantum controllable. We numerically study the quantum speed-limit, optimal parameters, and the fidelity of arbitrary state preparation and full SU(10) maps including the presence of decoherence due to optical pumping. We also study the use of robust control to mitigate some dephasing due to inhomogeneities in the light shift. We find that, we can prepare an arbitrary Haar-random state with average fidelity 0.9992, and an arbitrary Haar-random SU(10) unitary map with average fidelity 0.9923. The addition of Rydberg dressing together with the techniques above allows us to create any symmetric entangling two-qudit gate, such as CPHASE. Our techniques can be used to encode any qudit from d=2 to d=10 in the nuclear spin and thus provides a good platform to explore the various possibilities of quantum information processing of qudits including metrological enhancement with qudits, quantum simulation, and universal quantum computation

Read this article online: https://arxiv.org/abs/2106.13705, 9499R

(Session 5 : Thursday from 12:00pm-2:00 pm)