All-optical control of nuclear spin qudits in Alkaline-earth neutral atoms

Qudits with dimension d>2, can provide a powerful platform for quantum information processing [1].  We study encoding a d=10 level qudit in the nuclear spin of a ⁸⁷Sr atom.  The spin can be controlled by rapidly changing rf-magnetic fields [2], but bandwidth limitations may restrict controllability.  In this work we propose to control the qudits encoded in the nuclear spin in the ¹S₀  ground-state optically, using of vector and tensor light shifts [3] induced by a bichromatic field coupling to the ³P₁ excited-state. By modulating the polarization of this field, quantum optimal control techniques can be used to implement any unitary map in the group SU(10). These techniques benefit from foundational work in cesium [4], continued advances in optical clock based quantum information processing [5].

References:

1. [1] Y. Want et al, Frontiers in Physics 8 589504 (2020)
   
   [2] S. Omanakuttan et al, Phys. Rev. A 104, L060401(2021)
   
   [3] I. H. Deutsch and P. S. Jessen, Optics Communications 283, 681 (2010)
   
   [4] S. Chaudhury et. al, Phys. Rev. Lett.  99, 163002 (2007)
   
   [5] A. Cooper et al, Phys. Rev. X 8, 041055 (2018)