Micromotion minimization using Ramsey interferometry

Abstract

We minimize the stray electric field in a linear Paul trap quickly and accurately, by applying interferometry pulse sequences to a trapped ion optical qubit. The interferometry sequences are sensitive to the change of ion equilibrium position when the trap stiffness is changed, and we use this to determine the stray electric field. The simplest pulse sequence is a two-pulse Ramsey sequence, and longer sequences with multiple pulses offer a higher precision. The methods allow the stray field strength to be minimized beyond state-of-the-art levels, with only modest experimental requirements. Using a sequence of nine pulses we reduce the 2D stray field strength to $(10.5\pm 0.8)\mathrm{mV}{\mathrm{m}}^{-1}$ in $11\mathrm{s}$ measurement time. The pulse sequences are easy to implement and automate, and they are robust against laser detuning and pulse area errors. We use interferometry sequences with different lengths and precisions to measure the stray field with an uncertainty below the standard quantum limit. This marks a real-world case in which quantum metrology offers a significant enhancement. Also, we minimize micromotion in 2D using a single probe laser, by using an interferometry method together with the resolved sideband method; this is useful for experiments with restricted optical access. Furthermore, a technique presented in this work is related to quantum protocols for synchronising clocks; we demonstrate these protocols here.

arXiv commentMain text: 14 pages, 18 figures. Appendix: 5 pages, 4 figures

References in corpus (46)

• Quantum-enhanced measurements: beating the standard quantum limit
• Reference frames, superselection rules, and quantum information
• An ${}^{27}$Al${}^{+}$ quantum-logic clock with systematic uncertainty below $10^{-18}$
• Entanglement-free Heisenberg-limited phase estimation
• A trapped single ion inside a Bose-Einstein condensate
• Integrated multi-wavelength control of an ion qubit
• Dynamics of a cold trapped ion in a Bose-Einstein condensate
• Integrated optical multi-ion quantum logic
• Complete methods set for scalable ion trap quantum information processing
• Coupled quantized mechanical oscillators
• Observation of Cold Collisions between Trapped Ions and Trapped Atoms
• Single Ion Quantum Lock-In Amplifier
• Quantum-enhanced sensing of displacements and electric fields with large trapped-ion crystals
• Trapped-ion antennae for the transmission of quantum information
• Quantum algorithm for distributed clock synchronization
• Demonstrating Heisenberg-limited unambiguous phase estimation without adaptive measurements
• Robust Calibration of a Universal Single-Qubit Gate-Set via Robust Phase Estimation
• A single ion coupled to an optical fiber cavity
• Quantum methods for clock synchronization: Beating the standard quantum limit without entanglement
• Precise determination of micromotion for trapped-ion optical clocks
• Quantum-state transfer from an ion to a photon
• Tunable spin-spin interactions and entanglement of ions in separate wells
• Buffer gas cooling of a trapped ion to the quantum regime
• Linear Paul trap design for an optical clock with Coulomb crystals
• A high-precision rf trap with minimized micromotion for an In+ multiple-ion clock
• Active Stabilization of Ion Trap Radiofrequency Potentials
• Implementation of a symmetric surface electrode ion trap with field compensation using a modulated Raman effect
• On the application of radio frequency voltages to ion traps via helical resonators
• Photon collection from a trapped ion--cavity system
• Prospects for atomic clocks based on large ion crystals
• Electron impact ionization loading of a surface electrode ion trap
• A far-off-resonance optical trap for a Ba${}^{+}$ ion
• An ion ring in a linear multipole trap for optical frequency metrology
• Rydberg excitation of a single trapped ion
• Parameter Estimation with Mixed-State Quantum Computation
• Ion trajectory analysis for micromotion minimization and the measurement of small forces
• Experimental demonstration of cheap and accurate phase estimation
• Probing Time Dilation in Coulomb Crystals in a high-precision Ion Trap
• Operation of a planar-electrode ion-trap array with adjustable RF electrodes
• Direct Observation of Ion Micromotion in a Linear Paul Trap
• Minimization of ion micromotion using ultracold atomic probes
• Highly-polarizable ion in a Paul trap
• Measuring ion oscillations at the quantum level with fluorescence light
• Measurement of ion displacement via RF power variation for excess micromotion compensation
• Testing the Robustness of Robust Phase Estimation
• Minimizing rf-induced excess micromotion of a trapped ion with the help of ultracold atoms