Zeeman Degenerate Sideband Cooling in ${}^{176}$Lu${}^{+}$

Abstract

We explore degenerate Raman sideband cooling in which neighboring Zeeman states of a fixed hyperfine level are coupled via a two-photon Raman transition. The degenerate coupling between $|F,m_F⟩\to |F,m_F-1⟩$ facilitates the removal of multiple motional quanta in a single cycle. This method greatly reduces the number of cooling cycles required to reach the ground state compared to traditional sideband cooling. We show that near ground state cooling can be achieved with a pulse number as low as $\bar{n}$ where $\bar{n}$ is the average phonon number in the initial thermal state. We demonstrate proof-of-concept in ${}^{176}{\mathrm{Lu}}^{+}$ by coupling neighboring Zeeman levels on the motional sideband for the $F=7$ hyperfine level in ${}^3{D}_1$. Starting from a thermal distribution with an average phonon number of 6, we demonstrate near ground-state cooling with $\sim 10$ pulses. A theoretical description is given that applies to any $F$ level and demonstrates how effective this approach can be.

9 pages, 9 figures

References in corpus (16)

• Quantum computing with trapped ions
• Single-Ion Atomic Clock with $3\times 10^{-18}$ Systematic Uncertainty
• Heating of trapped ions from the quantum ground state
• Single ion-qubit exceeding one hour coherence time
• Dynamical polarizability of atoms in arbitrary light fields: general theory and application to cesium
• Zero-Point cooling and low heating of trapped 111Cd+ ions
• Sympathetic ground state cooling and time-dilation shifts in an ${}^{27}{\text{Al}}^{+}$ optical clock
• Linear Paul trap design for an optical clock with Coulomb crystals
• Resolved-sideband laser cooling in a Penning trap
• Efficient sympathetic motional ground-state cooling of a molecular ion
• Erasure-cooling, control, and hyper-entanglement of motion in optical tweezers
• Single-qubit gates with errors at the $10^{-7}$ level
• A Single Laser System for Ground-State Cooling of 25-Mg+
• Scalable, high-fidelity all-electronic control of trapped-ion qubits
• VECSEL systems for generation and manipulation of trapped magnesium ions
• Optimized pulsed sideband cooling and enhanced thermometry of trapped ions