Quantum logic control of a transition metal ion

TL;DR

This paper demonstrates quantum logic control of a complex transition metal ion, Ti+, using a combination of thermalization and quantum-logic techniques, enabling high-resolution spectroscopy and expanding possibilities for fundamental physics and astrophysics research.

Contribution

It introduces a novel method for controlling complex ions like Ti+ with quantum logic, combining thermalization and laser techniques, for the first time.

Findings

Successful quantum state preparation of Ti+ ions.

High-resolution Zeeman structure measurements achieved.

Applicable to a wide range of ionic species for fundamental physics.

Abstract

Extending quantum control to increasingly complex systems is crucial for both advancing quantum technologies and fundamental physics. In trapped ion systems, quantum logic techniques that combine a well-controlled logic species with a more complex spectroscopy species have proven to be a powerful tool for extending the range of accessible species. Here, we demonstrate that a quantum system as complex as $^{48}$Ti$^+$ with its many metastable states can be controlled employing a combination of intrinsic thermalization due to collisions with background gas and quantum-logic techniques using a far-detuned Raman laser. The preparation of pure quantum states allows coherent manipulation and high resolution measurements of the Zeeman structure in $^{48}$Ti$^+$. The presented techniques are applicable to a wide range of ionic species giving access to a larger variety of systems for fundamental physics and constitute the first step for quantum-controlled spectroscopy of transition metals, relevant, e.g., for the interpretation of astrophysical spectra.