arXiv subjects

Theodor Lukin Yelin

Publications and source records attributed to Theodor Lukin Yelin.

3 recordsLinked to original sources

arXiv2025

Assembling a Bose-Hubbard superfluid from tweezer-controlled single atoms

Quantum simulation relies on the preparation and control of low-entropy many-body systems to reveal the behavior of classically intractable models. The development of new approaches for realizing such systems therefore represents a frontier in quantum science. Here we experimentally demonstrate a new protocol for generating ultracold, itinerant many-body states in a tunnel-coupled two-dimensional optical lattice. We do this by adiabatically connecting a near-ground-state-cooled array of up to 50 single strontium-86 atoms with a Bose-Hubbard superfluid. Through comparison with finite-temperature quantum-Monte-Carlo calculations, we estimate that the entropy per particle of the prepared many-body states is approximately $2 k_B$, and that the achieved temperatures are consistent with a significant superfluid fraction. This represents the first time that itinerant many-body systems have been prepared from rearranged atoms, opening the door to bottom-up assembly of a wide range of neutral-atom and molecular systems.

cond-mat.quant-gas↗

arXiv2025

Autoionization-enhanced Rydberg dressing by fast contaminant removal

Rydberg dressing is a powerful tool for entanglement generation in long-lived atomic states. While already employed effectively in several demonstrations, a key challenge for this technique is the collective loss triggered by blackbody-radiation-driven transitions to contaminant Rydberg states of opposite parity. We demonstrate the rapid removal of such contaminants using autoionization (AI) transitions found in alkaline-earth-like atoms. The AI is shown to be compatible with coherent operation of an array of optical clock qubits. By incorporating AI pulses into a stroboscopic Rydberg dressing (SRD) sequence, we enhance lifetimes by an order of magnitude for system sizes of up to 144 atoms, while maintaining an order of magnitude larger duty cycle than previously achieved. To highlight the utility of our approach, we use the AI-enhanced SRD protocol to improve the degree of spin-squeezing achieved during early-time dressing dynamics. These results bring Rydberg dressing lifetimes closer to fundamental limits, opening the door to previously infeasible dressing proposals.

cond-mat.quant-gas↗

arXiv2024

Multi-qubit gates and Schrödinger cat states in an optical clock

Many-particle entanglement is a key resource for achieving the fundamental precision limits of a quantum sensor. Optical atomic clocks, the current state-of-the-art in frequency precision, are a rapidly emerging area of focus for entanglement-enhanced metrology. Augmenting tweezer-based clocks featuring microscopic control and detection with the high-fidelity entangling gates developed for atom-array information processing offers a promising route towards leveraging highly entangled quantum states for improved optical clocks. Here we develop and employ a family of multi-qubit Rydberg gates to generate Schrödinger cat states of the Greenberger-Horne-Zeilinger (GHZ) type with up to 9 optical clock qubits in a programmable atom array. In an atom-laser comparison at sufficiently short dark times, we demonstrate a fractional frequency instability below the standard quantum limit using GHZ states of up to 4 qubits. However, due to their reduced dynamic range, GHZ states of a single size fail to improve the achievable clock precision at the optimal dark time compared to unentangled atoms. Towards overcoming this hurdle, we simultaneously prepare a cascade of varying-size GHZ states to perform unambiguous phase estimation over an extended interval. These results demonstrate key building blocks for approaching Heisenberg-limited scaling of optical atomic clock precision.

quant-ph↗