S10-P32 magnetic quadrupole transition in neutral strontium

We present a detailed investigation of the ultranarrow magnetic-quadrupole ^S1₀-^P3₂ transition in neutral strontium and show how it can be made accessible for quantum simulation and quantum computation. By engineering the light shift in a one-dimensional optical lattice, we perform high-resolution spectroscopy and observe the characteristic absorption patterns for a magnetic quadrupole transition. We measure an absolute transition frequency of 446 ,647 ,242 ,704 (2 ) kHz in ⁸⁸Sr and an ⁸⁸Sr-⁸⁷Sr isotope shift of +62.91 (4 ) MHz. In a proof-of-principle experiment, we use this transition to demonstrate local addressing in an optical lattice with 532 nm spacing with a Rayleigh-criterion resolution of 494 (45 ) nm. Our results pave the way for applications of the magnetic quadrupole transition as an optical qubit and for single-site addressing in optical lattices.