Three-dimensional rearrangement of single atoms using actively controlled optical microtraps

Abstract

We propose and demonstrate three-dimensional rearrangements of single atoms. In experiments performed with single ⁸⁷Rb atoms in optical microtraps actively controlled by a spatial light modulator, we demonstrate various dynamic rearrangements of up to N = 9 atoms including rotation, 2D vacancy filling, guiding, compactification, and 3D shuffling. With the capability of a phase-only Fourier mask to generate arbitrary shapes of the holographic microtraps, it was possible to place single atoms at arbitrary geometries of a few μm size and even continuously reconfigure them by conveying each atom. For this purpose, we loaded a series of computer-generated phase masks in the full frame rate of 60 Hz of the spatial light modulator, so the animation of phase mask transformed the holographic microtraps in real time, driving each atom along the assigned trajectory. Possible applications of this method of transformation of single atoms include preparation of scalable quantum platforms for quantum computation, quantum simulation, and quantum many-body physics.

Atom-by-atom assembly of defect-free one-dimensional cold atom arrays

“…We use optical microtraps to directly extract individual atoms from a laser-cooled cloud [10][11][12] and employ recently demonstrated trapping techniques [13][14][15][16][17] and single-atom position control [18][19][20][21][22] to create desired atomic configurations. Central to our approach is the use of single-atom detection and real-time feedback [18,21,22] to eliminate the entropy associated with the probabilistic trap occupation [11] (currently limited to ninety percent even with advanced loading techniques [23][24][25]). Related to the fundamental concept of "Maxwell's demon" [8,9], this method allows us to rapidly create large defect-free atom arrays and to maintain them for long periods of time, providing an excellent platform for large-scale experiments based on techniques ranging from Rydberg-mediated interactions [26][27][28][29][30] to nanophotonic platforms [31,32] and Hubbard model physics [16,17,33].…”

“…We use optical microtraps to directly extract individual atoms from a laser-cooled cloud [10][11][12] and employ recently demonstrated trapping techniques [13][14][15][16][17] and single-atom position control [18][19][20][21][22] to create desired atomic configurations. Central to our approach is the use of single-atom detection and real-time feedback [18,21,22] to eliminate the entropy associated with the probabilistic trap occupation [11] (currently limited to ninety percent even with advanced loading techniques [23][24][25]).…”

Number-resolved imaging of $^{88}$Sr atoms in a long working distance optical tweezer

“…For imaging, we investigate a newly available type of camera based on an array of singlephoton-counting avalanche photodiodes. The low readout noise and high frame rate enables the presence of an atom to be determined with 0.989 (6) fidelity in an exposure time of just 200 µs. By employing existing Sisyphus cooling techniques [15,21], we show that it is possible to identify two atoms in the tweezer with a fidelity of 0.83 (2), but at the expense of a longer imaging time (30 ms) and higher loss.…”

Single atom movement with dynamic holographic optical tweezers

“…* straups@quantum.msu.ru An accepted way to resolve this problem is to create randomly filled array of tweezers, experimentally determine the tweezers that are filled with single atoms and to reconfigure these tweezers into a desired structure. Fully loaded 2D and 3D structures consisting of up to 50 atoms were created with an additional fully steerable dipole trap [16,22] or using computer generated dynamic holographic masks displayed on a spatial light modulator (SLM) [23][24][25].…”