A single ion as a shot noise limited magnetic field gradient probe

Abstract

It is expected that ion trap quantum computing can be made scalable through protocols that make use of transport of ion qubits between sub-regions within the ion trap. In this scenario, any magnetic field inhomogeneity the ion experiences during the transport, may lead to dephasing and loss of fidelity. Here we demonstrate how to measure, and compensate for, magnetic field gradients inside a segmented ion trap, by transporting a single ion over variable distances. We attain a relative magnetic field sensitivity of ΔB/B_0 ~ 5*10^{-7} over a test distance of 140 \micro m, which can be extended to the mm range, still with sub \micro m resolution. A fast experimental sequence is presented, facilitating its use as a magnetic field gradient calibration routine, and it is demonstrated that the main limitation is the quantum shot noise.

5 pages, 3 figures

References in corpus (3)

• 14-qubit entanglement: creation and coherence
• Complete methods set for scalable ion trap quantum information processing
• Optimization of segmented linear Paul traps and transport of stored particles

Cited by in corpus (7)

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• Two-Dimensional Arrays of RF Ion Traps with Addressable Interactions
• Estimation of gradients in quantum metrology
• Single-ion microwave near-field quantum sensor
• Entangled states of trapped ions allow measuring the magnetic field gradient of a single atomic spin
• Simulation of Quantum Magnetism in Mixed Spin Systems with Impurity Doped Ion Crystal