Low-Entropy States of Neutral Atoms in Polarization-Synthesized Optical Lattices

Abstract

We create low-entropy states of neutral atoms by utilizing a conceptually new optical-lattice technique that relies on a high-precision, high-bandwidth synthesis of light polarization. Polarization-synthesized optical lattices provide two fully controllable optical lattice potentials, each of them confining only atoms in either one of the two long-lived hyperfine states. By employing one lattice as the storage register and the other one as the shift register, we provide a proof of concept using four atoms that selected regions of the periodic potential can be filled with one particle per site. We expect that our results can be scaled up to thousands of atoms by employing an atom-sorting algorithm with logarithmic complexity, which is enabled by polarization-synthesized optical lattices. Vibrational entropy is subsequently removed by sideband cooling methods. Our results pave the way for a bottom-up approach to creating ultralow-entropy states of a many-body system.

Defect-Free Assembly of 2D Clusters of More Than 100 Single-Atom Quantum Systems

“…For the submicron spaced periodic potentials of optical lattices, the preparation of a central region with nearunity filling has been demonstrated in two-dimensional (2D) quantum gas microscopes [7,[14][15][16][17][18][19]. Accurate repositioning of individual atoms has been implemented for four atoms in a one-dimensional polarization-synthesized optical lattice [20], but unrestricted individual atom transport remains a challenge in these lattices for higher atom numbers and dimensionality.…”

Atomic “bomb testing”: the Elitzur–Vaidman experiment violates the Leggett–Garg inequality

“…At the core of our realization of the Elitzur-Vaidman experiment with trapped atoms are polarization-synthesized (PS) optical lattices, which were recently introduced by Robens et al [28]: two one-dimensional, periodic optical potentials can be independently shifted along their common longitudinal direction to selectively transport atoms in either one of two internal states, |↑� and |↓�. In essence, two copropagating laser beams of opposite circular polarization interfere with a third, counterpropagating, linearly polarized beam.…”

“…Compared to former realizations of state-dependent optical lattices, PS optical lattices have replaced the polarization control formerly based on an electro-optic modulator by a direct synthesis of light polarization, which enable arbitrary, state-dependent displacements of atoms. Polarization synthesis is realized through rf-control of the optical phases (0.1 • RMS phase jitter) of two overlapped beams with opposite circular polarization [28].…”

Super-resolution microscopy of single atoms in optical lattices

“…x NA N f (assuming only shot noise), the twenty times larger collection solid angle and the four times narrower PSF should enable single-site resolution with exposure times around ( · ) » 1000 ms 16 20 3 ms.…”

“…Single-atom localization methods are employed in our laboratories ever since to measure the spatial probability distribution of atoms performing discrete-time quantum walks [12,18,19]. Recent experiments in our laboratory beyond single particle physics require resolving the position of each individual atom in small clusters at high filling factors, even when each lattice site is occupied [20]. By exploiting the discreteness of the atoms' positions in the lattice, we demonstrate in this manuscript new methods that enable resolving clusters of atoms with high reliability.…”