Zeeman-Splitting-Assisted Quantum Logic Spectroscopy of Trapped Ions

TL;DR

This paper introduces a quantum logic spectroscopy method using Zeeman splitting to identify atomic and molecular ion states via magnetic g-factors, enabling state detection through motional sidebands.

Contribution

It presents a novel Zeeman-splitting-based quantum logic scheme for detecting ion states, including molecular rotational states, with experimental proof-of-principle demonstrations.

Findings

Successfully detected the ground electronic state of Yb+ using a logic ion.

Distinguished between different electronic states of Yb+ ions.

Discussed applicability to molecular ion rotational state detection.

Abstract

We present a quantum logic scheme to detect atomic and molecular ions in different states of angular momentum based on their magnetic $g$-factors. The state-dependent magnetic $g$-factors mean that electronic, rotational or hyperfine states may be distinguished by their Zeeman splittings in a given magnetic field. Driving motional sidebands of a chosen Zeeman splitting enables reading out the corresponding state of angular momentum with an auxillary logic ion. As a proof-of-principle demonstration, we show that we can detect the ground electronic state of a ${^{174}}$Yb$^+$ ion using ${^{171}}$Yb$^+$ as the logic ion. Further, we can distinguish between the ${^{174}}$Yb$^+$ ion being in its ground electronic state versus the metastable ${^{2}}D_{3/2}$ state. We discuss the suitability of this scheme for the detection of rotational states in molecular ions.