Resolved-sideband Micromotion Sensing in Yb$^{+}$ on the 935 nm Repump Transition

TL;DR

This paper demonstrates a novel method for sensing ion micromotion in Yb$^{+}$ ions using the 935 nm repump transition, offering a low-overhead, surface-electrode compatible approach for quantum applications.

Contribution

The authors introduce a resolved-sideband micromotion sensing technique utilizing the 935 nm repump transition in Yb$^{+}$ ions, which is simpler and more compatible with surface traps than existing methods.

Findings

Successful measurement of 3D micromotion in Yb$^{+}$ ions.

Method shows low technical overhead and high compatibility with surface-electrode traps.

Applicable to both $^{172}$Yb$^{+}$ and $^{171}$Yb$^{+}$ isotopes.

Abstract

Ions displaced from the potential minimum in a RF Paul trap exhibit excess micromotion. A host of well-established techniques are routinely used to sense (and null) this excess motion in applications ranging from quantum computing to atomic clocks. The rich atomic structure of the heavy ion Yb$^{+}$ includes low-lying $^{2}\text{D}_{3/2}$ states that must be repumped to permit Doppler cooling, typically using a 935 nm laser coupled to the $^{3}\text{D}[3/2]_{1/2}$ states. In this manuscript we demonstrate the use of this transition to make resolved-sideband measurements of 3D micromotion in $^{172}$Yb$^{+}$ and $^{171}$Yb$^{+}$ ions. Relative to other sensing techniques our approach has very low technical overhead and is distinctively compatible with surface-electrode ion traps.