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We report the preparation of Bose-Einstein condensates (BECs) by integrating laser cooling with a grating magneto-optical trap (GMOT) and forced evaporation in a magnetic trap on a single chip. This new approach allowed us to produce a $6…

Degenerate quantum gases are instrumental in advancing many-body quantum physics and underpin emerging precision sensing technologies. All state-of-the-art experiments use evaporative cooling to achieve the ultracold temperatures needed for…

Preparation of molecular quantum gas promises novel applications including quantum control of chemical reactions, precision measurements, quantum simulation and quantum information processing. Experimental preparation of colder and denser…

Atomic Physics · Physics 2021-04-29 Zhendong Zhang , Liangchao Chen , Kaixuan Yao , Cheng Chin

Not all generate-and-test search algorithms are created equal. Bayesian Optimization (BO) invests a lot of computation time to generate the candidate solution that best balances the predicted value and the uncertainty given all previous…

Neural and Evolutionary Computing · Computer Science 2020-05-11 Gongjin Lan , Jakub M. Tomczak , Diederik M. Roijers , A. E. Eiben

We experimentally and numerically investigate thermalization processes of a trapped $^{87}$Rb Bose gas, initially prepared in a non-equilibrium state through partial Bragg diffraction of a Bose-Einstein condensate (BEC). The system evolves…

Quantum Gases · Physics 2018-07-18 D. J. Brown , A. V. H. McPhail , D. H. White , D. Baillie , S. K. Ruddell , M. D. Hoogerland

Ensembles of particles governed by quantum mechanical laws exhibit fascinating emergent behavior. Atomic quantum gases, liquid helium, and electrons in quantum materials all show distinct properties due to their composition and…

In cosmological evolution, it is the homogeneous scalar field (inflaton) that drives the universe to expand isotropically and to generate standard model particles. However, to simulate cosmology, atomic gas research has focused on the…

Quantum Gases · Physics 2024-01-23 Ke Wang , Han Fu , K. Levin

Ultra-cold atomic gases are unique in terms of the degree of controllability, both for internal and external degrees of freedom. This makes it possible to use them for the study of complex quantum many-body phenomena. However in many…

Quantum Physics · Physics 2020-09-30 Rick Mukherjee , Frederic Sauvage , Harry Xie , Robert Löw , Florian Mintert

Bose-Einstein condensation (BEC) in a gas has now been achieved. Alkali atoms ($^{87}Rb$, $^{23}Na$ and $^{7}Li$) have been cooled to the point of condensation (temperature of 100 nK) using laser cooling and trapping, followed by magnetic…

Quantum Physics · Physics 2016-09-08 Luca Salasnich

We study the optimization of evaporative cooling in trapped bosonic atoms on the basis of quantum kinetic theory of a Bose gas. The optimized cooling trajectory for $^{87}$Rb atoms indicates that the acceleration of evaporative cooling…

Statistical Mechanics · Physics 2009-11-07 Makoto Yamashita , Masato Koashi , Tetsuya Mukai , Masaharu Mitsunaga , Nobuyuki Imoto , Takaaki Mukai

Continuously measured interacting quantum systems almost invariably heat, causing loss of quantum coherence. Here, we study Bose-Einstein condensates (BECs) subject to repeated weak measurement of the atomic density and describe several…

Quantum Gases · Physics 2023-06-28 Evan P. Yamaguchi , Hilary M. Hurst , I. B. Spielman

State engineering of quantum objects is a central requirement in most implementations. In the cases where the quantum dynamics can be described by analytical solutions or simple approximation models, optimal state preparation protocols have…

The recent achievement of Bose-Einstein condensation of chromium atoms [1] has opened longed-for experimental access to a degenerate quantum gas with long-range and anisotropic interaction. Due to the large magnetic moment of chromium atoms…

Other Condensed Matter · Physics 2007-05-23 Axel Griesmaier , Jürgen Stuhler , Tilman Pfau

We present and characterize an experimental system in which we achieve the integration of an ultrahigh finesse optical cavity with a Bose-Einstein condensate (BEC). The conceptually novel design of the apparatus for the production of BECs…

Other Condensed Matter · Physics 2016-08-16 Anton Öttl , Stephan Ritter , Michael Köhl , Tilman Esslinger

The dynamics of Bose-Einstein condensation in a three-dimensional harmonic trap is studied explicitly including the Bogoliubov approximation for temperatures below the critical one. To model the evolution towards equilibrium at each cooling…

Quantum Gases · Physics 2015-06-22 A. Camacho-Guardian , M. Mendoza López , V. Romero-Rochín , R. Paredes

We report on the successful extension of production of Bose-Einstein Condensate (BEC) to rare species. Despite its low natural abundance of 0.13%, $^{168}$Yb is directly evaporatively cooled down to BEC. Our successful demonstration…

Atomic Physics · Physics 2021-10-01 Seiji Sugawa , Rekishu Yamazaki , Shintaro Taie , Yoshiro Takahashi

At low-temperatures a gas of bosons will undergo a phase transition into a quantum state of matter known as a Bose-Einstein condensate (BEC), in which a large fraction of the particles will occupy the ground state simultaneously. Here we…

We present an experimental apparatus that produces Bose-Einstein condensates (BECs) of $^{87}$Rb atoms at a rate of 1 Hz. As a demonstration of the system's ability to operate continuously, 30 BECs were produced and imaged in 32.1 s.…

Atomic Physics · Physics 2014-12-30 Daniel M. Farkas , Evan A. Salim , Jaime Ramirez-Serrano

This paper investigates numerical methods for approximating the ground state of Bose--Einstein condensates (BECs) by introducing two relaxed formulations of the Gross--Pitaevskii energy functional. These formulations achieve first- and…

Numerical Analysis · Mathematics 2025-07-30 Jing Guo , Yongyong Cai , Dong Wang

The problem of understanding how a coherent, macroscopic Bose-Einstein condensate (BEC) emerges from the cooling of a thermal Bose gas has attracted significant theoretical and experimental interest over several decades. The pioneering…