Coherent Manipulation of a Ca Spin Qubit in a Micro Ion Trap

TL;DR

This paper demonstrates coherent control of a calcium ion spin qubit in a micro ion trap, achieving high-fidelity operations and analyzing trap-induced heating effects.

Contribution

It introduces a method for coherent manipulation of a Ca ion spin qubit with high fidelity in a micro trap, including initialization, readout, and heating rate analysis.

Findings

Qubit initialization and readout efficiency of 99.5%

Single qubit rotation fidelity of 96%

Trap-induced heating rate of 0.3 phonons/ms

Abstract

We demonstrate the implementation of a spin qubit with a single Ca ion in a micro ion trap. The qubit is encoded in the Zeeman ground state levels mJ=+1/2 and mJ=-1/2 of the S1/2 state of the ion. We show sideband cooling close to the vibrational ground state and demonstrate the initialization and readout of the qubit levels with 99.5% efficiency. We employ a Raman transition close to the S1/2 - P1/2 resonance for coherent manipulation of the qubit. We observe single qubit rotations with 96% fidelity and gate times below 5mus. Rabi oscillations on the blue motional sideband are used to extract the phonon number distribution. The dynamics of this distribution is analyzed to deduce the trap-induced heating rate of 0.3(1) phonons/ms.