1
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Lu J, Ginis V, Lim SWD, Capasso F. Helicity and Polarization Gradient Optical Trapping in Evanescent Fields. PHYSICAL REVIEW LETTERS 2023; 131:143803. [PMID: 37862648 DOI: 10.1103/physrevlett.131.143803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 09/13/2023] [Indexed: 10/22/2023]
Abstract
Optical traps using nonconservative forces instead of conservative intensity-gradient forces expand the trap parameter space. Existing traps with nonconservative helicity-dependent forces are limited to chiral particles and fields with helicity gradients. We relax these constraints by proposing helicity and polarization gradient optical trapping of achiral particles in evanescent fields. We further propose an optical switching system in which a microsphere is trapped and optically manipulated around a microfiber using polarization gradients. Our Letter deepens the understanding of light-matter interactions in polarization gradient fields and expands the range of compatible particles and stable trapping fields.
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Affiliation(s)
- Jinsheng Lu
- Harvard John A. Paulson School of Engineering and Applied Sciences, 9 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Vincent Ginis
- Harvard John A. Paulson School of Engineering and Applied Sciences, 9 Oxford Street, Cambridge, Massachusetts 02138, USA
- Data Lab and Applied Physics, Vrije Universiteit Brussel, 1050 Brussel, Belgium
| | - Soon Wei Daniel Lim
- Harvard John A. Paulson School of Engineering and Applied Sciences, 9 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Federico Capasso
- Harvard John A. Paulson School of Engineering and Applied Sciences, 9 Oxford Street, Cambridge, Massachusetts 02138, USA
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2
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Li J, Chen X, Ruschhaupt A. Fast transport of Bose-Einstein condensates in anharmonic traps. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2022; 380:20210280. [PMID: 36335948 PMCID: PMC9653254 DOI: 10.1098/rsta.2021.0280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
We present a method to transport Bose-Einstein condensates (BECs) in anharmonic traps and in the presence of atom-atom interactions in short times without residual excitation. Using a combination of a variational approach and inverse engineering methods, we derive a set of Ermakov-like equations that take into account the coupling between the centre of mass motion and the breathing mode. By an appropriate inverse engineering strategy of those equations, we then design the trap trajectory to achieve the desired boundary conditions. Numerical examples for cubic or quartic anharmonicities are provided for fast and high-fidelity transport of BECs. Potential applications are atom interferometry and quantum information processing. This article is part of the theme issue 'Shortcuts to adiabaticity: theoretical, experimental and interdisciplinary perspectives'.
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Affiliation(s)
- Jing Li
- Department of Physics, University College Cork, Cork, T12 H6T1 Ireland
| | - Xi Chen
- Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080 Bilbao, Spain
- EHU Quantum Center, University of the Basque Country UPV/EHU, 48940 Leioa, Spain
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3
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Seo M, Do IH, Lee H, Yu DH, Seo S, Hong HG, Han JH, Park SE, Lee SB, Kwon TY, Mun J, Lee JH. Moving-frame imaging of transiting cold atoms for precise long-range transport. OPTICS EXPRESS 2022; 30:25707-25717. [PMID: 36237095 DOI: 10.1364/oe.464087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 06/20/2022] [Indexed: 06/16/2023]
Abstract
Transporting cold atoms between interconnected vacuum chambers is an important technique for increasing the versatility of cold atom setups, particularly for those that couple atoms to photonic devices. In this report, we introduce a method where we are able to image the atoms at all points during transport via moving optical dipole trap. Cooled 87Rb atoms are transported ∼50 cm into an auxiliary vacuum chamber while being monitored with a moving-frame imaging system for which in-situ characterization of the atom transport is demonstrated. Precise positioning of the atoms near photonic devices is also tested across several tapered fibers showing an axial positioning resolution of ∼450 μm.
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4
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Li X, Luo X, Wang S, Xie K, Liu XP, Hu H, Chen YA, Yao XC, Pan JW. Second sound attenuation near quantum criticality. Science 2022; 375:528-533. [PMID: 35113717 DOI: 10.1126/science.abi4480] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Second sound attenuation, a distinctive dissipative hydrodynamic phenomenon in a superfluid, is crucial for understanding superfluidity and elucidating critical phenomena. Here, we report the observation of second sound attenuation in a homogeneous Fermi gas of lithium-6 atoms at unitarity by performing Bragg spectroscopy with high energy resolution in the long-wavelength limit. We successfully obtained the temperature dependence of second sound diffusivity [Formula: see text] and thermal conductivity κ. Furthermore, we observed a sudden rise-a precursor of critical divergence-in both [Formula: see text] and κ at a temperature of about 0.95 superfluid transition temperature [Formula: see text]. This suggests that the unitary Fermi gas has a much larger critical region than does liquid helium. Our results pave the way for determining the universal critical scaling functions near quantum criticality.
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Affiliation(s)
- Xi Li
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
| | - Xiang Luo
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
| | - Shuai Wang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
| | - Ke Xie
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
| | - Xiang-Pei Liu
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
| | - Hui Hu
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.,Centre for Quantum Technology Theory, Swinburne University of Technology, Melbourne, VIC 3122, Australia
| | - Yu-Ao Chen
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
| | - Xing-Can Yao
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
| | - Jian-Wei Pan
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
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5
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Abstract
Bose–Einstein condensates (BECs), a state of matter formed when a low-density gas of bosons is cooled to near absolute zero, continue to motivate novel work in theoretical and experimental physics. Although BECs are most commonly studied in stationary ground states, time-varying BECs arise when some aspect of the physics governing the condensate varies as a function of time. We study the evolution of time-varying BECs under non-autonomous Gross–Pitaevskii equations (GPEs) through a mix of theory and numerical experiments. We separately derive a perturbation theory (in the small-parameter limit) and a variational approximation for non-autonomous GPEs on generic bounded space domains. We then explore various routes to obtain time-varying BECs, starting with the more standard techniques of varying the potential, scattering length, or dispersion, and then moving on to more advanced control mechanisms such as moving the external potential well over time to move or even split the BEC cloud. We also describe how to modify a BEC cloud through evolution of the size or curvature of the space domain. Our results highlight a variety of interesting theoretical routes for studying and controlling time-varying BECs, lending a stronger theoretical formulation for existing experiments and suggesting new directions for future investigation.
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Affiliation(s)
- Robert A. Van Gorder
- Department of Mathematics and Statistics, University of Otago, PO Box 56, Dunedin 9054, New Zealand
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6
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Li J, Chen Z, Liu Y, Kollipara PS, Feng Y, Zhang Z, Zheng Y. Opto-refrigerative tweezers. SCIENCE ADVANCES 2021; 7:7/26/eabh1101. [PMID: 34172454 PMCID: PMC8232904 DOI: 10.1126/sciadv.abh1101] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 05/12/2021] [Indexed: 05/29/2023]
Abstract
Optical tweezers offer revolutionary opportunities for both fundamental and applied research in materials science, biology, and medical engineering. However, the requirement of a strongly focused and high-intensity laser beam results in potential photon-induced and thermal damages to target objects, including nanoparticles, cells, and biomolecules. Here, we report a new type of light-based tweezers, termed opto-refrigerative tweezers, which exploit solid-state optical refrigeration and thermophoresis to trap particles and molecules at the laser-generated cold region. While laser refrigeration can avoid photothermal heating, the use of a weakly focused laser beam can further reduce the photodamages to the target object. This novel and noninvasive optical tweezing technique will bring new possibilities in the optical control of nanomaterials and biomolecules for essential applications in nanotechnology, photonics, and life science.
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Affiliation(s)
- Jingang Li
- Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA
| | - Zhihan Chen
- Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA
| | - Yaoran Liu
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX 78705, USA
| | | | - Yichao Feng
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an, Shaanxi 710062, China
| | - Zhenglong Zhang
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an, Shaanxi 710062, China
| | - Yuebing Zheng
- Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA.
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX 78705, USA
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
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7
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Unnikrishnan G, Beulenkamp C, Zhang D, Zamarski KP, Landini M, Nägerl HC. Long distance optical transport of ultracold atoms: A compact setup using a Moiré lens. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:063205. [PMID: 34243520 DOI: 10.1063/5.0049320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/26/2021] [Indexed: 06/13/2023]
Abstract
We present a compact and robust setup to optically transport ultracold atoms over long distances. Using a focus-tunable moiré lens that has recently appeared in the market, we demonstrate transport of up to a distance of 465 mm. A transfer efficiency of 70% is achieved with a negligible temperature change at 11 μK. With its high thermal stability and low astigmatism, the moiré lens is superior to fluid-based varifocal lenses. It is much more compact and stable than a lens mounted on a linear translation stage, allowing for simplified experimental setups.
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Affiliation(s)
- G Unnikrishnan
- Institut für Experimentalphysik und Zentrum für Quantenphysik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - C Beulenkamp
- Institut für Experimentalphysik und Zentrum für Quantenphysik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - D Zhang
- Institut für Experimentalphysik und Zentrum für Quantenphysik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - K P Zamarski
- Institut für Experimentalphysik und Zentrum für Quantenphysik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - M Landini
- Institut für Experimentalphysik und Zentrum für Quantenphysik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - H-C Nägerl
- Institut für Experimentalphysik und Zentrum für Quantenphysik, Universität Innsbruck, 6020 Innsbruck, Austria
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8
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Chen X, Fan B. The emergence of picokelvin physics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2020; 83:076401. [PMID: 32303019 DOI: 10.1088/1361-6633/ab8ab6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The frontier of low-temperature physics has advanced to the mid-picokelvin (pK) regime but progress has come to a halt because of the problem of gravity. Ultracold atoms must be confined in some type of potential energy well: if the depth of the well is less than the energy an atom gains by falling through it, the atom escapes. This article reviews ultracold atom research, emphasizing the advances that carried the low-temperature frontier to 450 pK. We review microgravity methods for overcoming the gravitational limit to achieving lower temperatures using free-fall techniques such as a drop tower, sounding rocket, parabolic flight plane and the International Space Station. We describe two techniques that promise further advancement-an atom chip and an all-optical trap-and present recent experimental results. Basic research in new regimes of observation has generally led to scientific discoveries and new technologies that benefit society. We expect this to be the case as the low-temperature frontier advances and we propose some new opportunities for research.
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Affiliation(s)
- Xuzong Chen
- Institute of Quantum Electronics, Department of Electronics, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, People's Republic of China
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9
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Lasnoy E, Wagner O, Edri E, Shpaisman H. Drag controlled formation of polymeric colloids with optical traps. LAB ON A CHIP 2019; 19:3543-3551. [PMID: 31555788 DOI: 10.1039/c9lc00672a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Optical trapping is a powerful optical manipulation technique for controlling various mesoscopic systems that allows formation of tailor-made polymeric micro-sized colloids by directed coalescence of nucleation sites. However, control over the size of a single colloid requires constant monitoring of the growth process and deactivation of the optical trap once it reaches the required dimensions. Moreover, producing more than one colloid requires moving the sample to a pristine location where the process must be repeated. Here, we present a novel method for continuous control over formation of polydimethylsiloxane colloids based on directed coalescence induced by optical traps under flow inside microfluidic channels. Once the drag force on a growing colloid exceeds the trapping force, it leaves the optical trap, and a new colloid starts to form at the same location. We demonstrate repeatability of the process and selectively produce colloids with radii of ∼1-14 μm by controlling the laser intensity and flow rate. In addition, holographic optical tweezers are used to show how multiple optical traps in 3D could be used to influence a significant cross section of the micro-channel, thus forming a light-controlled assembly line for colloidal formation.
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Affiliation(s)
- Erel Lasnoy
- Department of Chemistry and Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, 5290002, Israel.
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10
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Abstract
Acoustic tweezers use sound radiation forces to manipulate matter without contact. They provide unique characteristics compared with the more established optical tweezers, such as higher trapping forces per unit input power and the ability to manipulate objects from the micrometer to the centimeter scale. They also enable the trapping of a wide range of sample materials in various media. A dramatic advancement in optical tweezers was the development of holographic optical tweezers (HOT) which enabled the independent manipulation of multiple particles leading to applications such as the assembly of 3D microstructures and the probing of soft matter. Now, 20 years after the development of HOT, we present the realization of holographic acoustic tweezers (HAT). We experimentally demonstrate a 40-kHz airborne HAT system implemented using two 256-emitter phased arrays and manipulate individually up to 25 millimetric particles simultaneously. We show that the maximum trapping forces are achieved once the emitting array satisfies Nyquist sampling and an emission phase discretization below π/8 radians. When considered on the scale of a wavelength, HAT provides similar manipulation capabilities as HOT while retaining its unique characteristics. The examples shown here suggest the future use of HAT for novel forms of displays in which the objects are made of physical levitating voxels, assembly processes in the micrometer and millimetric scale, as well as positioning and orientation of multiple objects which could lead to biomedical applications.
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Affiliation(s)
- Asier Marzo
- Faculty of Engineering, University of Bristol, BS8 1TR Bristol, United Kingdom;
- UpnaLab, Universidad Pública de Navarra, Campus Arrosadia, 31006 Pamplona, Spain
| | - Bruce W Drinkwater
- Faculty of Engineering, University of Bristol, BS8 1TR Bristol, United Kingdom
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11
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Porter MD, Giera B, Panas RM, Shaw LA, Shusteff M, Hopkins JB. Experimental characterization and modeling of optical tweezer particle handling dynamics. APPLIED OPTICS 2018; 57:6565-6571. [PMID: 30117897 DOI: 10.1364/ao.57.006565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 07/05/2018] [Indexed: 06/08/2023]
Abstract
We report a new framework for a quantitative understanding of optical trapping (OT) particle handling dynamics. We present a novel three-dimensional particle-based model that includes optical, hydrodynamic, and inter-particle forces. This semi-empirical colloid model is based on an open-source simulation code known as LAMMPS (large-scale atomic/molecular massively parallel simulator) and properly recapitulates the full OT force profile beyond the typical linear approximations valid near the trap center. Simulations are carried out with typical system parameters relevant for our experimental holographic optical trapping (HOT) system, including varied particle sizes, trap movement speeds, and beam powers. Furthermore, we present a new experimental method for measuring both the stable and metastable boundaries of the optical force profile to inform or validate the model's underlying force profile. We show that our framework is a powerful tool for accurately predicting particle behavior in a practical experimental OT setup and can be used to characterize and predict particle handling dynamics within any arbitrary OT force profile.
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12
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Shaw LA, Chizari S, Hopkins JB. Improving the throughput of automated holographic optical tweezers. APPLIED OPTICS 2018; 57:6396-6402. [PMID: 30117869 DOI: 10.1364/ao.57.006396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/30/2018] [Indexed: 06/08/2023]
Abstract
The purpose of this work is to introduce three improvements to automated holographic-optical-tweezers systems that increase the number and speed of particles that can be manipulated simultaneously. First, we address path planning by solving a bottleneck assignment problem, which can reduce total move time by up to 30% when compared with traditional assignment problem solutions. Next, we demonstrate a new strategy to identify and remove undesired (e.g., misshapen or agglomerated) particles. Finally, we employ a controller that combines both closed- and open-loop automation steps, which can increase the overall loop rate and average particle speeds while also utilizing necessary process monitoring checks to ensure that particles reach their destinations. Using these improvements, we show fast reconfiguration of 100 microspheres simultaneously with a closed-loop control rate of 6, and 10 Hz by employing both closed- and open-loop steps. We also demonstrate the closed-loop assembly of a large pattern in a continuously flowing microchannel-based particle-delivery system. The proposed approach provides a promising path toward automatic and scalable assembly of microgranular structures.
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13
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Sukhov S, Dogariu A. Non-conservative optical forces. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:112001. [PMID: 28762956 DOI: 10.1088/1361-6633/aa834e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Undoubtedly, laser tweezers are the most recognized application of optically induced mechanical action. Their operation is usually described in terms of conservative forces originating from intensity gradients. However, the fundamental optical action on matter is non-conservative. We will review different manifestations of non-conservative optical forces (NCF) and discuss their dependence on the specific spatial properties of optical fields that generate them. New developments relevant to the NCF such as tractor beams and transversal forces are also discussed.
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Affiliation(s)
- Sergey Sukhov
- CREOL, The College of Optics and Photonics, University of Central Florida, 4000 Central Florida Blvd., Orlando, FL 32816, United States of America
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14
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Kalfagiannis N, Siozios A, Bellas DV, Toliopoulos D, Bowen L, Pliatsikas N, Cranton WM, Kosmidis C, Koutsogeorgis DC, Lidorikis E, Patsalas P. Selective modification of nanoparticle arrays by laser-induced self assembly (MONA-LISA): putting control into bottom-up plasmonic nanostructuring. NANOSCALE 2016; 8:8236-8244. [PMID: 27031573 DOI: 10.1039/c5nr09192f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Nano-structuring of metals is one of the greatest challenges for the future of plasmonic and photonic devices. Such a technological challenge calls for the development of ultra-fast, high-throughput and low-cost fabrication techniques. Laser processing, accounts for the aforementioned properties, representing an unrivalled tool towards the anticipated arrival of modules based in metallic nanostructures, with an extra advantage: the ease of scalability. In the present work we take advantage of the ability to tune the laser wavelength to either match the absorption spectral profile of the metal or to be resonant with the plasma oscillation frequency, and demonstrate the utilization of different optical absorption mechanisms that are size-selective and enable the fabrication of pre-determined patterns of metal nanostructures. Thus, we overcome the greatest challenge of Laser Induced Self Assembly by combining simultaneously large-scale character with atomic-scale precision. The proposed process can serve as a platform that will stimulate further progress towards the engineering of plasmonic devices.
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Affiliation(s)
- Nikolaos Kalfagiannis
- Nottingham Trent University, School of Science and Technology, Nottingham, NG11 8NS, UK
| | - Anastasios Siozios
- University of Ioannina, Department of Materials Science and Engineering, 45110 Ioannina, Greece
| | - Dimitris V Bellas
- University of Ioannina, Department of Materials Science and Engineering, 45110 Ioannina, Greece
| | - Dimosthenis Toliopoulos
- University of Ioannina, Department of Materials Science and Engineering, 45110 Ioannina, Greece
| | - Leon Bowen
- University of Durham, G. J. Russell Microscopy Facility, South Road, Durham, DH1 3LE, UK
| | - Nikolaos Pliatsikas
- Aristotle University of Thessaloniki, Department of Physics, 54124 Thessaloniki, Greece
| | - Wayne M Cranton
- Nottingham Trent University, School of Science and Technology, Nottingham, NG11 8NS, UK and Sheffield Hallam University, Materials and Engineering Research Institute, Sheffield, S11 WB, UK
| | | | | | - Elefterios Lidorikis
- University of Ioannina, Department of Materials Science and Engineering, 45110 Ioannina, Greece
| | - Panos Patsalas
- Aristotle University of Thessaloniki, Department of Physics, 54124 Thessaloniki, Greece
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15
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Roberts KO, McKellar T, Fekete J, Rakonjac A, Deb AB, Kjærgaard N. Steerable optical tweezers for ultracold atom studies. OPTICS LETTERS 2014; 39:2012-2015. [PMID: 24686662 DOI: 10.1364/ol.39.002012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report on the implementation of an optical tweezer system for controlled transport of ultracold atoms along a narrow, static confinement channel. The tweezer system is based on high-efficiency acousto-optic deflectors and offers two-dimensional control over beam position. This opens up the possibility for tracking the transport channel when shuttling atomic clouds along it, forestalling atom spilling. Multiple clouds can be tracked independently by time-shared tweezer beams addressing individual sites in the channel. The deflectors are controlled using a multichannel direct digital synthesizer, which receives instructions on a submicrosecond time scale from a field-programmable gate array. Using the tweezer system, we demonstrate sequential binary splitting of an ultracold 87Rb cloud into 2(5) clouds.
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16
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Sarshar M, Wong WT, Anvari B. Comparative study of methods to calibrate the stiffness of a single-beam gradient-force optical tweezers over various laser trapping powers. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:115001. [PMID: 25375348 PMCID: PMC4221290 DOI: 10.1117/1.jbo.19.11.115001] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 09/16/2014] [Accepted: 09/29/2014] [Indexed: 05/13/2023]
Abstract
Optical tweezers have become an important instrument in force measurements associated with various physical, biological, and biophysical phenomena. Quantitative use of optical tweezers relies on accurate calibration of the stiffness of the optical trap. Using the same optical tweezers platform operating at 1064 nm and beads with two different diameters, we present a comparative study of viscous drag force, equipartition theorem, Boltzmann statistics, and power spectral density (PSD) as methods in calibrating the stiffness of a single beam gradient force optical trap at trapping laser powers in the range of 0.05 to 1.38 W at the focal plane. The equipartition theorem and Boltzmann statistic methods demonstrate a linear stiffness with trapping laser powers up to 355 mW, when used in conjunction with video position sensing means. The PSD of a trapped particle's Brownian motion or measurements of the particle displacement against known viscous drag forces can be reliably used for stiffness calibration of an optical trap over a greater range of trapping laser powers. Viscous drag stiffness calibration method produces results relevant to applications where trapped particle undergoes large displacements, and at a given position sensing resolution, can be used for stiffness calibration at higher trapping laser powers than the PSD method.
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Affiliation(s)
- Mohammad Sarshar
- University of California, Department of Bioengineering, Riverside, California 92521, United States
| | - Winson T. Wong
- University of California, Department of Bioengineering, Riverside, California 92521, United States
| | - Bahman Anvari
- University of California, Department of Bioengineering, Riverside, California 92521, United States
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17
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Schmidt OA, Euser TG, Russell PSJ. Mode-based microparticle conveyor belt in air-filled hollow-core photonic crystal fiber. OPTICS EXPRESS 2013; 21:29383-29391. [PMID: 24514492 DOI: 10.1364/oe.21.029383] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We show how microparticles can be moved over long distances and precisely positioned in a low-loss air-filled hollow-core photonic crystal fiber using a coherent superposition of two co-propagating spatial modes, balanced by a backward-propagating fundamental mode. This creates a series of trapping positions spaced by half the beat-length between the forward-propagating modes (typically a fraction of a millimeter). The system allows a trapped microparticle to be moved along the fiber by continuously tuning the relative phase between the two forward-propagating modes. This mode-based optical conveyor belt combines long-range transport of microparticles with a positional accuracy of 1 µm. The technique also has potential uses in waveguide-based optofluidic systems.
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18
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Morrissey MJ, Deasy K, Frawley M, Kumar R, Prel E, Russell L, Truong VG, Chormaic SN. Spectroscopy, manipulation and trapping of neutral atoms, molecules, and other particles using optical nanofibers: a review. SENSORS 2013; 13:10449-81. [PMID: 23945738 PMCID: PMC3812613 DOI: 10.3390/s130810449] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 07/18/2013] [Accepted: 08/01/2013] [Indexed: 11/16/2022]
Abstract
The use of tapered optical fibers, i.e., optical nanofibers, for spectroscopy and the detection of small numbers of particles, such as neutral atoms or molecules, has been gaining interest in recent years. In this review, we briefly introduce the optical nanofiber, its fabrication, and optical mode propagation within. We discuss recent progress on the integration of optical nanofibers into laser-cooled atom and vapor systems, paying particular attention to spectroscopy, cold atom cloud characterization, and optical trapping schemes. Next, a natural extension of this work to molecules is introduced. Finally, we consider several alternatives to optical nanofibers that display some advantages for specific applications.
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Affiliation(s)
- Michael J. Morrissey
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa; E-Mail:
| | - Kieran Deasy
- Light-Matter Interactions Unit, OIST Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan; E-Mails: (K.D.); (M.F.); (R.K.); (E.P.); (L.R.); (V.G.T.)
| | - Mary Frawley
- Light-Matter Interactions Unit, OIST Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan; E-Mails: (K.D.); (M.F.); (R.K.); (E.P.); (L.R.); (V.G.T.)
- Physics Department, University College Cork, Cork, Ireland
| | - Ravi Kumar
- Light-Matter Interactions Unit, OIST Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan; E-Mails: (K.D.); (M.F.); (R.K.); (E.P.); (L.R.); (V.G.T.)
- Physics Department, University College Cork, Cork, Ireland
| | - Eugen Prel
- Light-Matter Interactions Unit, OIST Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan; E-Mails: (K.D.); (M.F.); (R.K.); (E.P.); (L.R.); (V.G.T.)
- Physics Department, University College Cork, Cork, Ireland
| | - Laura Russell
- Light-Matter Interactions Unit, OIST Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan; E-Mails: (K.D.); (M.F.); (R.K.); (E.P.); (L.R.); (V.G.T.)
- Physics Department, University College Cork, Cork, Ireland
| | - Viet Giang Truong
- Light-Matter Interactions Unit, OIST Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan; E-Mails: (K.D.); (M.F.); (R.K.); (E.P.); (L.R.); (V.G.T.)
| | - Síle Nic Chormaic
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa; E-Mail:
- Light-Matter Interactions Unit, OIST Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan; E-Mails: (K.D.); (M.F.); (R.K.); (E.P.); (L.R.); (V.G.T.)
- Physics Department, University College Cork, Cork, Ireland
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +81-98-966-1551
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19
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Gattobigio GL, Couvert A, Reinaudi G, Georgeot B, Guéry-Odelin D. Optically guided beam splitter for propagating matter waves. PHYSICAL REVIEW LETTERS 2012; 109:030403. [PMID: 22861829 DOI: 10.1103/physrevlett.109.030403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 05/21/2012] [Indexed: 06/01/2023]
Abstract
We study experimentally and theoretically a beam splitter setup for guided atomic matter waves. The matter wave is a guided atom laser that can be tuned from quasimonomode to a regime where many transverse modes are populated, and propagates in a horizontal dipole beam until it crosses another horizontal beam at 45°. We show that depending on the parameters of this X configuration, the atoms can all end up in one of the two beams (the system behaves as a perfect guide switch), or be split between the four available channels (the system behaves as a beam splitter). The splitting regime results from a chaotic scattering dynamics. The existence of these different regimes turns out to be robust against small variations of the parameters of the system. From numerical studies, we also propose a scheme that provides a robust and controlled beam splitter in two channels only.
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Affiliation(s)
- G L Gattobigio
- Laboratoire de Collisions Agrégats Réactivité, CNRS UMR 5589, IRSAMC, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cedex 4, France
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20
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Brazhnyi VA, Malomed BA. Dragging two-dimensional discrete solitons by moving linear defects. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 84:016608. [PMID: 21867335 DOI: 10.1103/physreve.84.016608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 04/12/2011] [Indexed: 05/31/2023]
Abstract
We study the mobility of small-amplitude solitons attached to moving defects which drag the solitons across a two-dimensional (2D) discrete nonlinear Schrödinger lattice. Findings are compared to the situation when a free small-amplitude 2D discrete soliton is kicked in a uniform lattice. In agreement with previously known results, after a period of transient motion the free soliton transforms into a localized mode pinned by the Peierls-Nabarro potential, irrespective of the initial velocity. However, the soliton attached to the moving defect can be dragged over an indefinitely long distance (including routes with abrupt turns and circular trajectories) virtually without losses, provided that the dragging velocity is smaller than a certain critical value. Collisions between solitons dragged by two defects in opposite directions are studied too. If the velocity is small enough, the collision leads to a spontaneous symmetry breaking, featuring fusion of two solitons into a single one, which remains attached to either of the two defects.
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Affiliation(s)
- Valeriy A Brazhnyi
- Centro de Física do Porto, Faculdade de Ciências, Universidade do Porto, Porto, Portugal.
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21
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Lengwenus A, Kruse J, Schlosser M, Tichelmann S, Birkl G. Coherent transport of atomic quantum states in a scalable shift register. PHYSICAL REVIEW LETTERS 2010; 105:170502. [PMID: 21231030 DOI: 10.1103/physrevlett.105.170502] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Revised: 08/31/2010] [Indexed: 05/30/2023]
Abstract
We demonstrate the coherent transport of 2D arrays of small ensembles of neutral atoms in a shift register architecture based on 2D arrays of microlenses. We show the scalability of the transport process by presenting the repeated hand over of atoms from site to site. We prove the conservation of coherence during transport, reloading, and a full shift register cycle. This shows that the fundamental shift sequence can be cascaded and thus scaled to complex and versatile 2D architectures for atom-based quantum information processing, quantum simulation, and the investigation of quantum degenerate gases.
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Affiliation(s)
- A Lengwenus
- Institut für Angewandte Physik, Technische Universität Darmstadt, Germany
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22
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Müller T, Zimmermann B, Meineke J, Brantut JP, Esslinger T, Moritz H. Local observation of antibunching in a trapped Fermi gas. PHYSICAL REVIEW LETTERS 2010; 105:040401. [PMID: 20867821 DOI: 10.1103/physrevlett.105.040401] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Indexed: 05/29/2023]
Abstract
Local density fluctuations and density profiles of a Fermi gas are measured in situ and analyzed. In the quantum degenerate regime, the weakly interacting 6Li gas shows a suppression of the density fluctuations compared to the nondegenerate case, where atomic shot noise is observed. This manifestation of antibunching is a direct result of the Pauli principle and constitutes a local probe of quantum degeneracy. We analyze our data using the predictions of the fluctuation-dissipation theorem and the local density approximation, demonstrating a fluctuation-based temperature measurement.
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Affiliation(s)
- Torben Müller
- Institute for Quantum Electronics, ETH Zurich, 8093 Zurich, Switzerland
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23
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Xiong D, Wang P, Fu Z, Zhang J. Transport of Bose-Einstein condensate in QUIC trap and separation of trapping spin states. OPTICS EXPRESS 2010; 18:1649-1656. [PMID: 20173992 DOI: 10.1364/oe.18.001649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have studied the locomotion track of (87)Rb Bose-Einstein condensate during decompressing the trap into the center of the glass cell in a quadrupole-Ioffe configuration trap. In order to change the position of the BEC, the current in the quadrupole coils is reduced while the current in the Ioffe coil keeps constant. Because of the strongly reduced trap frequencies of the moved trap, the BEC considerably sags down due to the gravity. Thus an inflexion point exists in the process of moving BEC. When rubidium atoms go over the inflexion point, they cannot keep in balance under the gravity and the force provided by a magnetic field, and flow downward and towards Ioffe coil. By utilizing this effect, the trapped atoms with the spin state |F = 2,mF = 1>, which are left over in the BEC, can be separated from the BEC of |F = 2,mF = 2> state.
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Affiliation(s)
- Dezhi Xiong
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan, P.R.China
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24
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Fang F, Weiss DS. Resonator-enhanced optical guiding and trapping of Cs atoms. OPTICS LETTERS 2009; 34:169-171. [PMID: 19148244 DOI: 10.1364/ol.34.000169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrate a 90 cm launch of Cs atoms guided by a one-dimensional (1D) optical lattice. The 1064 nm wavelength optical lattice is made in a 2 m long buildup cavity and provides a transverse guide depth of up to 125 microK. Before they reach the top of their trajectory, the atoms are stopped and cooled by optical molasses, becoming trapped in the 1D lattice. The lattice can be loaded with multiple launches, filling sites that extend over 5 cm. The trap is far from all magnetic sources and will be used for a precision measurement of the electron electric-dipole moment.
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Affiliation(s)
- Fang Fang
- Department of Physics, 104 Davey Lab, The Pennsylvania State University, University Park, PA 16802, USA
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25
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Cano D, Kasch B, Hattermann H, Kleiner R, Zimmermann C, Koelle D, Fortágh J. Meissner effect in superconducting microtraps. PHYSICAL REVIEW LETTERS 2008; 101:183006. [PMID: 18999830 DOI: 10.1103/physrevlett.101.183006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Indexed: 05/27/2023]
Abstract
We report on the realization and characterization of a magnetic microtrap for ultracold atoms near a straight superconducting Nb wire with circular cross section. The trapped atoms are used to probe the magnetic field outside the superconducting wire. The Meissner effect shortens the distance between the trap and the wire, reduces the radial magnetic-field gradients, and lowers the trap depth. Measurements of the trap position reveal a complete exclusion of the magnetic field from the superconducting wire for temperatures lower than 6 K. As the temperature is further increased, the magnetic field partially penetrates the superconducting wire; hence the microtrap position is shifted towards the position expected for a normal-conducting wire.
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Affiliation(s)
- D Cano
- Physikalisches Institut, Eberhard-Karls-Universität Tübingen, CQ Center for Collective Quantum Phenomena and their Applications, Auf der Morgenstelle 14, D-72076 Tübingen, Germany
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26
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Cran-McGreehin S, Krauss TF, Dholakia K. Integrated monolithic optical manipulation. LAB ON A CHIP 2006; 6:1122-4. [PMID: 16929390 DOI: 10.1039/b605237a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We present a new approach to optical manipulation that integrates microfluidic channels directly onto semiconductor laser material creating a compact integrated optical trap that requires no alignment and is wholly portable.
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Affiliation(s)
- Simon Cran-McGreehin
- SUPA, Department of Physics and Astronomy, North Haugh, University of St Andrews, St Andrews, Fife, KY16 9SS, UK.
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27
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Kim WJ, Brownell JH, Onofrio R. Detectability of dissipative motion in quantum vacuum via superradiance. PHYSICAL REVIEW LETTERS 2006; 96:200402. [PMID: 16803156 DOI: 10.1103/physrevlett.96.200402] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Indexed: 05/10/2023]
Abstract
We propose an experiment for generating and detecting vacuum-induced dissipative motion. A high frequency mechanical resonator driven in resonance is expected to dissipate mechanical energy in quantum vacuum via photon emission. The photons are stored in a high quality electromagnetic cavity and detected through their interaction with ultracold alkali-metal atoms prepared in an inverted population of hyperfine states. Superradiant amplification of the generated photons results in a detectable radio-frequency signal temporally distinguishable from the expected background.
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Affiliation(s)
- Woo-Joong Kim
- Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, New Hampshire 03755, USA
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28
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Joykutty J, Mathur V, Venkataraman V, Natarajan V. Direct measurement of the oscillation frequency in an optical-tweezers trap by parametric excitation. PHYSICAL REVIEW LETTERS 2005; 95:193902. [PMID: 16383979 DOI: 10.1103/physrevlett.95.193902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Indexed: 05/05/2023]
Abstract
We demonstrate a novel technique for direct measurement of the oscillation frequency in an optical-tweezers trap. The technique uses the phenomenon of parametric resonance in an oscillator when the stiffness of the trapping potential is modulated. The trapped particle is a strongly damped oscillator; hence, the signature of parametric resonance is not an increase in the amplitude but an increase in the size of Brownian fluctuations. The trap frequency is measured with an accuracy of 0.1%, which is better than previous techniques and thus opens up new possibilities in experiments with optical tweezers.
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Affiliation(s)
- Joji Joykutty
- Department of Physics, Indian Institute of Science, Bangalore 560 012, India
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29
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Fatemi F, Bashkansky M, Moore S. Side-illuminated hollow-core optical fiber for atom guiding. OPTICS EXPRESS 2005; 13:4890-4895. [PMID: 19498475 DOI: 10.1364/opex.13.004890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrate a technique for coupling guiding light into hollow-core optical fibers for atom guiding. Microprisms embedded into a multimode, double-clad hollow fiber, allow light to be coupled into the fiber at multiple locations along the length of the fiber. The technique offers significant advantages over end-pumped configurations.
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30
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Fu LB, Chen SG. Topology hidden behind the breakdown of adiabaticity. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:016607. [PMID: 15697747 DOI: 10.1103/physreve.71.016607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2004] [Revised: 10/13/2004] [Indexed: 05/24/2023]
Abstract
For classical Hamiltonian systems, the adiabatic condition may fail at some critical points. However, the breakdown of the adiabatic condition does not always cause the adiabatic evolution to be destroyed. In this paper, we suggest a supplemental condition of the adiabatic evolution for the fixed points of classical Hamiltonian systems when the adiabatic condition breaks down at the critical points. As an example, we investigate the adiabatic evolution of the fixed points of a classical Hamiltonian system which has a number of applications.
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Affiliation(s)
- Li-Bin Fu
- Institute of Applied Physics and Computational Mathematics, P.O. Box 8009 (28), 100088 Beijing, China
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31
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Shin Y, Saba M, Vengalattore M, Pasquini TA, Sanner C, Leanhardt AE, Prentiss M, Pritchard DE, Ketterle W. Dynamical instability of a doubly quantized vortex in a Bose-Einstein condensate. PHYSICAL REVIEW LETTERS 2004; 93:160406. [PMID: 15524962 DOI: 10.1103/physrevlett.93.160406] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2004] [Indexed: 05/24/2023]
Abstract
Doubly quantized vortices were topologically imprinted in /F=1> 23Na condensates, and their time evolution was observed using a tomographic imaging technique. The decay into two singly quantized vortices was characterized and attributed to dynamical instability. The time scale of the splitting process was found to be longer at higher atom density.
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Affiliation(s)
- Y Shin
- MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Abstract
A new type of optical cw atom laser design is proposed that should operate at high intensity and high coherence and possibly record low temperatures. It is based on an "optical-shepherd" technique, in which far-off-resonance blue-detuned swept sheet laser beams are used to make new types of high-density traps, atom waveguides, and other components for achieving very efficient Bose-Einstein condensation and cw atom laser operation. A shepherd-enhanced trap is proposed that should be superior to conventional magneto-optic traps for the initial collection of molasses-cooled atoms. A type of dark-spot optical trap is devised that can cool large numbers of atoms to polarization-gradient temperatures at densities limited only by three-body collisional loss. A scheme is designed to use shepherd beams to capture and recycle essentially all of the escaped atoms in evaporative cooling, thereby increasing the condensate output by several orders of magnitude. Condensate atoms are stored in a shepherd trap, protected from absorbing light, under effectively zero-gravity conditions, and coupled out directly into an optical waveguide. Many experiments and devices may be possible with this cw atom laser.
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Affiliation(s)
- Arthur Ashkin
- Bell Laboratories, Lucent Technologies (Retired), Holmdel, NJ 07733-3030, USA.
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33
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Shin Y, Saba M, Schirotzek A, Pasquini TA, Leanhardt AE, Pritchard DE, Ketterle W. Distillation of bose-einstein condensates in a double-well potential. PHYSICAL REVIEW LETTERS 2004; 92:150401. [PMID: 15169269 DOI: 10.1103/physrevlett.92.150401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2003] [Indexed: 05/24/2023]
Abstract
Bose-Einstein condensates of sodium atoms, prepared in an optical dipole trap, were distilled into a second empty dipole trap adjacent to the first one. The distillation was driven by thermal atoms spilling over the potential barrier separating the two wells and then forming a new condensate. This process serves as a model system for metastability in condensates, provides a test for quantum kinetic theories of condensate formation, and also represents a novel technique for creating or replenishing condensates in new locations.
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Affiliation(s)
- Y Shin
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Shin Y, Saba M, Pasquini TA, Ketterle W, Pritchard DE, Leanhardt AE. Atom interferometry with Bose-Einstein condensates in a double-well potential. PHYSICAL REVIEW LETTERS 2004; 92:050405. [PMID: 14995291 DOI: 10.1103/physrevlett.92.050405] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2003] [Indexed: 05/24/2023]
Abstract
A trapped-atom interferometer was demonstrated using gaseous Bose-Einstein condensates coherently split by deforming an optical single-well potential into a double-well potential. The relative phase between the two condensates was determined from the spatial phase of the matter wave interference pattern formed upon releasing the condensates from the separated potential wells. Coherent phase evolution was observed for condensates held separated by 13 microm for up to 5 ms and was controlled by applying ac Stark shift potentials to either of the two separated condensates.
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Affiliation(s)
- Y Shin
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Abstract
Optical tweezers use the forces exerted by a strongly focused beam of light to trap and move objects ranging in size from tens of nanometres to tens of micrometres. Since their introduction in 1986, the optical tweezer has become an important tool for research in the fields of biology, physical chemistry and soft condensed matter physics. Recent advances promise to take optical tweezers out of the laboratory and into the mainstream of manufacturing and diagnostics; they may even become consumer products. The next generation of single-beam optical traps offers revolutionary new opportunities for fundamental and applied research.
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Affiliation(s)
- David G Grier
- Department of Physics, James Franck Institute and Institute for Biophysical Dynamics, The University of Chicago, 5640 S. Ellis Avenue, Chicago, IL 60637, USA.
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36
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Liu J, Wu B, Niu Q. Nonlinear evolution of quantum states in the adiabatic regime. PHYSICAL REVIEW LETTERS 2003; 90:170404. [PMID: 12786058 DOI: 10.1103/physrevlett.90.170404] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2002] [Indexed: 05/24/2023]
Abstract
We investigate adiabatic evolution of quantum states as governed by the nonlinear Schrödinger equation and provide examples of applications with a nonlinear tunneling model for Bose-Einstein condensates. Our analysis not only spells out conditions for adiabatic evolution of eigenstates but also characterizes the motion of noneigenstates which cannot be obtained from the former in the absence of the superposition principle. We find that Aharonov-Anandan phases play the role of classical canonical actions and are conserved in the adiabatic evolution of noneigenstates.
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Affiliation(s)
- Jie Liu
- Department of Physics, The University of Texas, Austin, Texas 78712, USA
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37
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Leanhardt AE, Shin Y, Kielpinski D, Pritchard DE, Ketterle W. Coreless vortex formation in a spinor Bose-Einstein condensate. PHYSICAL REVIEW LETTERS 2003; 90:140403. [PMID: 12731900 DOI: 10.1103/physrevlett.90.140403] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2002] [Indexed: 05/24/2023]
Abstract
Coreless vortices were phase imprinted in a spinor Bose-Einstein condensate. The three-component order parameter of F=1 sodium condensates held in a Ioffe-Pritchard magnetic trap was manipulated by adiabatically reducing the magnetic bias field along the trap axis to zero. This distributed the condensate population across its three spin states and created a spin texture. Each spin state acquired a different phase winding which caused the spin components to separate radially.
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Affiliation(s)
- A E Leanhardt
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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38
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Kasper A, Schneider S, Hagen CV, Bartenstein M, Engeser B, Schumm T, Bar-Joseph I, Folman R, Feenstra L, Schmiedmayer J. A Bose Einstein condensate in a microtrap. ACTA ACUST UNITED AC 2003. [DOI: 10.1088/1464-4266/5/2/372] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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39
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Leanhardt AE, Shin Y, Chikkatur AP, Kielpinski D, Ketterle W, Pritchard DE. Bose-Einstein condensates near a microfabricated surface. PHYSICAL REVIEW LETTERS 2003; 90:100404. [PMID: 12688985 DOI: 10.1103/physrevlett.90.100404] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2002] [Indexed: 05/24/2023]
Abstract
Magnetically and optically confined Bose-Einstein condensates were studied near a microfabricated surface. Condensate fragmentation observed in microfabricated magnetic traps was not observed in optical dipole traps at the same location. The measured condensate lifetime was >or=20 s and independent of the atom-surface separation under both magnetic and optical confinement. Radio-frequency spin-flip transitions driven by technical noise were directly observed for optically confined condensates and could limit the condensate lifetime in microfabricated magnetic traps.
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Affiliation(s)
- A E Leanhardt
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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40
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Görlitz A, Gustavson TL, Leanhardt AE, Löw R, Chikkatur AP, Gupta S, Inouye S, Pritchard DE, Ketterle W. Sodium Bose-Einstein condensates in the F = 2 state in a large-volume optical trap. PHYSICAL REVIEW LETTERS 2003; 90:090401. [PMID: 12689206 DOI: 10.1103/physrevlett.90.090401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2002] [Indexed: 05/24/2023]
Abstract
We have investigated the properties of Bose-Einstein condensates of sodium atoms in the upper hyperfine ground state. Condensates in the high-field seeking [F=2, m(F)=-2> state were created in a large volume optical trap from initially prepared [F=1, m(F)=-1> condensates using a microwave transition at 1.77 GHz. We found condensates in the stretched state [F=2, m(F)=-2> to be stable for several seconds at densities in the range of 10(14) atoms/cm(3). In addition, we studied the clock transition [F=1, m(F)=0> --> [F=2, m(F)=0> in a sodium Bose-Einstein condensate and determined a density-dependent frequency shift of (2.44+/-0.25+/-0.5) x 10(-12) Hz cm(3).
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Affiliation(s)
- A Görlitz
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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Leanhardt AE, Görlitz A, Chikkatur AP, Kielpinski D, Shin Y, Pritchard DE, Ketterle W. Imprinting vortices in a Bose-Einstein condensate using topological phases. PHYSICAL REVIEW LETTERS 2002; 89:190403. [PMID: 12443104 DOI: 10.1103/physrevlett.89.190403] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2002] [Indexed: 05/24/2023]
Abstract
Vortices were imprinted in a Bose-Einstein condensate using topological phases. Sodium condensates held in a Ioffe-Pritchard magnetic trap were transformed from a nonrotating state to one with quantized circulation by adiabatically inverting the magnetic bias field along the trap axis. Using surface wave spectroscopy, the axial angular momentum per particle of the vortex states was found to be consistent with 2 variant Planck's over 2pi or 4 variant Planck's over 2pi, depending on the hyperfine state of the condensate.
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Affiliation(s)
- A E Leanhardt
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Das KK, Girardeau MD, Wright EM. Interference of a thermal tonks gas on a ring. PHYSICAL REVIEW LETTERS 2002; 89:170404. [PMID: 12398652 DOI: 10.1103/physrevlett.89.170404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2002] [Indexed: 05/24/2023]
Abstract
A nonzero temperature generalization of the Fermi-Bose mapping theorem is used to study the exact quantum statistical dynamics of a one-dimensional gas of impenetrable bosons on a ring. We investigate the interference produced when an initially trapped gas localized on one side of the ring is released, split via an optical-dipole grating, and recombined on the other side of the ring. Nonzero temperature is shown not to be a limitation to obtaining high visibility fringes.
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Affiliation(s)
- Kunal K Das
- Optical Sciences Center and Department of Physics, University of Arizona, Tucson, Arizona 85721, USA
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Gupta S, Dieckmann K, Hadzibabic Z, Pritchard DE. Contrast interferometry using Bose-Einstein condensates to measure h/m and alpha. PHYSICAL REVIEW LETTERS 2002; 89:140401. [PMID: 12366031 DOI: 10.1103/physrevlett.89.140401] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2002] [Indexed: 05/23/2023]
Abstract
The kinetic energy of an atom recoiling due to absorption of a photon was measured as a frequency, using an interferometric technique called "contrast interferometry." Optical standing wave pulses were used to create a symmetric three-path interferometer with a Bose-Einstein condensate. Its recoil phase, measurable with a single shot, varies quadratically with additional recoils and is insensitive to errors from vibrations and ac Stark shifts. We have measured the photon recoil frequency of sodium to 7 ppm precision, using a simple realization of this scheme. Plausible extensions should yield sufficient precision to attain a ppb-level determination of h/m and the fine structure constant alpha.
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Affiliation(s)
- S Gupta
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139, USA
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Leanhardt AE, Chikkatur AP, Kielpinski D, Shin Y, Gustavson TL, Ketterle W, Pritchard DE. Propagation of Bose-Einstein condensates in a magnetic waveguide. PHYSICAL REVIEW LETTERS 2002; 89:040401. [PMID: 12144470 DOI: 10.1103/physrevlett.89.040401] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2002] [Indexed: 05/23/2023]
Abstract
Gaseous Bose-Einstein condensates of 2-3 x 10(6) 23Na atoms were loaded into a microfabricated magnetic trap using optical tweezers. Subsequently, the condensates were released into a magnetic waveguide and propagated 12 mm. Single-mode propagation was observed along homogeneous segments of the waveguide. Inhomogeneities in the guiding potential arose from geometric deformations of the microfabricated wires and caused strong transverse excitations. Such deformations may restrict the waveguide physics that can be explored with propagating condensates. Finer perturbations to the guiding potential fragmented the condensate when it was brought closer to the surface.
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Affiliation(s)
- A E Leanhardt
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Chikkatur AP, Shin Y, Leanhardt AE, Kielpinski D, Tsikata E, Gustavson TL, Pritchard DE, Ketterle W. A continuous source of Bose-Einstein condensed atoms. Science 2002; 296:2193-5. [PMID: 12077408 DOI: 10.1126/science.296.5576.2193] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A continuous source of Bose-Einstein condensed sodium atoms was created by periodically replenishing a condensate held in an optical dipole trap with new condensates delivered using optical tweezers. The source contained more than 1 x 10(6) atoms at all times, raising the possibility of realizing a continuous atom laser.
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Affiliation(s)
- A P Chikkatur
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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