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Isichenko A, Chauhan N, Bose D, Wang J, Kunz PD, Blumenthal DJ. Photonic integrated beam delivery for a rubidium 3D magneto-optical trap. Nat Commun 2023; 14:3080. [PMID: 37248247 DOI: 10.1038/s41467-023-38818-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 05/17/2023] [Indexed: 05/31/2023] Open
Abstract
Cold atoms are important for precision atomic applications including timekeeping and sensing. The 3D magneto-optical trap (3D-MOT), used to produce cold atoms, will benefit from photonic integration to improve reliability and reduce size, weight, and cost. These traps require the delivery of multiple, large area, collimated laser beams to an atomic vacuum cell. Yet, to date, beam delivery using an integrated waveguide approach has remained elusive. Here we report the demonstration of a 87Rb 3D-MOT using a fiber-coupled photonic integrated circuit to deliver all beams to cool and trap > 1 ×106 atoms to near 200 μK. The silicon nitride photonic circuit transforms fiber-coupled 780 nm cooling and repump light via waveguides to three mm-width non-diverging free-space cooling and repump beams directly to the rubidium cell. This planar, CMOS foundry-compatible integrated beam delivery is compatible with other components, such as lasers and modulators, promising system-on-chip solutions for cold atom applications.
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Affiliation(s)
- Andrei Isichenko
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Nitesh Chauhan
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Debapam Bose
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Jiawei Wang
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Paul D Kunz
- DEVCOM U.S. Army Research Laboratory, Adelphi, MD, 20783, USA
| | - Daniel J Blumenthal
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.
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2
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Wang Y, Li Y, Wu J, Liu W, Hu J, Ma J, Xiao L, Jia S. Hybrid evaporative cooling of 133Cs atoms to Bose-Einstein condensation. OPTICS EXPRESS 2021; 29:13960-13967. [PMID: 33985122 DOI: 10.1364/oe.419854] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 04/14/2021] [Indexed: 06/12/2023]
Abstract
The Bose-Einstein condensation (BEC) of 133Cs atoms offers an appealing platform for studying the many-body physics of interacting Bose quantum gases, owing to the rich Feshbach resonances that can be readily achieved in the low magnetic field region. However, it is notoriously difficult to cool 133Cs atoms to their quantum degeneracy. Here we report a hybrid evaporative cooling of 133Cs atoms to BEC. Our approach relies on a combination of the magnetically tunable evaporation with the optical evaporation of atoms in a magnetically levitated optical dipole trap overlapping with a dimple trap. The magnetic field gradient is reduced for the magnetically tunable evaporation. The subsequent optical evaporation is performed by lowering the depth of the dimple trap. We study the dependence of the peak phase space density (PSD) and temperature on the number of atoms during the evaporation process, as well as how the PSD and atom number vary with the trap depth. The results are in excellent agreement with the equation model for evaporative cooling.
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3
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Solano P, Duan Y, Chen YT, Rudelis A, Chin C, Vuletić V. Strongly Correlated Quantum Gas Prepared by Direct Laser Cooling. PHYSICAL REVIEW LETTERS 2019; 123:173401. [PMID: 31702268 DOI: 10.1103/physrevlett.123.173401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Indexed: 06/10/2023]
Abstract
We create a one-dimensional strongly correlated quantum gas of ^{133}Cs atoms with attractive interactions by direct laser cooling in 300 ms. After compressing and cooling the optically trapped atoms to the vibrational ground state along two tightly confined directions, the emergence of a non-Gaussian time-of-flight distribution along the third, weakly confined direction reveals that the system enters a quantum degenerate regime. We observe a reduction of two- and three-body spatial correlations and infer that the atoms are directly cooled into a highly correlated excited metastable state, known as a super-Tonks-Girardeau gas.
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Affiliation(s)
- Pablo Solano
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Yiheng Duan
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Yu-Ting Chen
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Alyssa Rudelis
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Cheng Chin
- James Franck Institute, Enrico Fermi Institute, Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - Vladan Vuletić
- 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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4
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Sovkov VB, Xie F, Lyyra AM, Ahmed EH, Ma J, Jia S. Re-examination of the Cs 2 ground singlet X 1Σ g+ and triplet a 3Σ u+ states. J Chem Phys 2017; 147:104301. [PMID: 28915738 DOI: 10.1063/1.5001481] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This paper clarifies the disagreement in the depth of the potential energy curve of the cesium dimer singlet ground state which has lasted for nearly a decade. We point out that the origin of this disagreement must be a technical misprint in the values of the three binding energies reported by Danzl et al. [Science 321, 1062 (2008)], while the X1Σg+ state potential reported by Coxon and Hajigeorgiou [J. Chem. Phys. 132, 094105 (2010)], based on experimental data by Amiot and Dulieu [J. Chem. Phys. 117, 5155 (2002)], is quite correct. We have recalculated the potential energy function of the triplet ground state a3Σu+ by using the available experimental data spanning both the attractive and the repulsive branches so that the potential energy function complies asymptotically with the singlet ground state X1Σg+ potential energy function by Coxon and Hajigeorgiou. This is important for the simulation of the near dissociation properties such as Feshbach resonances, which are typically observed in modern experiments with ultracold atoms and molecules.
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Affiliation(s)
- Vladimir B Sovkov
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia
| | - Feng Xie
- Institute of Nuclear and New Energy Technology, Collaborative Innovation Center of Advanced Nuclear Energy Technology, Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Tsinghua University, Beijing 100084, China
| | - A Marjatta Lyyra
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122-6082, USA
| | - Ergin H Ahmed
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122-6082, USA
| | - Jie Ma
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser spectroscopy, College of Physics and Electronics, Shanxi University, Taiyuan 030006, China
| | - Suotang Jia
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser spectroscopy, College of Physics and Electronics, Shanxi University, Taiyuan 030006, China
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5
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Hosseini M, Duan Y, Beck KM, Chen YT, Vuletić V. Cavity Cooling of Many Atoms. PHYSICAL REVIEW LETTERS 2017; 118:183601. [PMID: 28524680 DOI: 10.1103/physrevlett.118.183601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate cavity cooling of all motional degrees of freedom of an atomic ensemble using light that is far detuned from the atomic transitions by several gigahertz. The cooling is achieved by cavity-induced frequency-dependent asymmetric enhancement of the atomic emission spectrum, thereby extracting thermal kinetic energy from the atomic system. Within 100 ms, the atomic temperature is reduced from 200 to 10 μK, where the final temperature is mainly limited by the linewidth of the cavity. In principle, the technique can be applied to molecules and atoms with complex internal energy structure.
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Affiliation(s)
- Mahdi Hosseini
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Yiheng Duan
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Kristin M Beck
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Yu-Ting Chen
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Vladan Vuletić
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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6
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Ma J, Li Y, Wu J, Xiao L, Jia S. Laser intensity induced transparency in atom-molecular transition process. CHINESE SCIENCE BULLETIN-CHINESE 2014. [DOI: 10.1007/s11434-014-0448-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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7
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Boixo S, Datta A, Davis MJ, Flammia ST, Shaji A, Caves CM. Quantum metrology: dynamics versus entanglement. PHYSICAL REVIEW LETTERS 2008; 101:040403. [PMID: 18764311 DOI: 10.1103/physrevlett.101.040403] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Indexed: 05/26/2023]
Abstract
A parameter whose coupling to a quantum probe of n constituents includes all two-body interactions between the constituents can be measured with an uncertainty that scales as 1/n3/2, even when the constituents are initially unentangled. We devise a protocol that achieves the 1/n3/2 scaling without generating any entanglement among the constituents, and we suggest that the protocol might be implemented in a two-component Bose-Einstein condensate.
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Affiliation(s)
- Sergio Boixo
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131-0001, USA
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8
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Pricoupenko L. Resonant scattering of ultracold atoms in low dimensions. PHYSICAL REVIEW LETTERS 2008; 100:170404. [PMID: 18518261 DOI: 10.1103/physrevlett.100.170404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Indexed: 05/26/2023]
Abstract
Low energy scattering amplitudes for two atoms in one- and two-dimensional atomic waveguides are derived for short range isotropic and resonant interactions in high partial wave channels. Taking into account the finite width of the resonance which was neglected in previous works is shown to have important implications in the properties of the confinement induced resonances. For spin polarized fermions in quasi-1D waveguides, it imposes a strong constraint on the atomic density for achieving the Fermi Tonks Girardeau gas. For a planar waveguide, the characteristics of the 2D induced scattering resonances in p- and d-waves are determined as a function of the 3D scattering parameters and of the waveguide frequency.
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Affiliation(s)
- Ludovic Pricoupenko
- Laboratoire de Physique Théorique de la Matière Condensée, Université Pierre et Marie Curie, case courier 121, 4 place Jussieu, 75252 Paris Cedex 05, France
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9
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Roati G, Zaccanti M, D'Errico C, Catani J, Modugno M, Simoni A, Inguscio M, Modugno G. 39K Bose-Einstein condensate with tunable interactions. PHYSICAL REVIEW LETTERS 2007; 99:010403. [PMID: 17678142 DOI: 10.1103/physrevlett.99.010403] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Indexed: 05/16/2023]
Abstract
We produce a Bose-Einstein condensate of 39K atoms. Condensation of this species with a naturally small and negative scattering length is achieved by a combination of sympathetic cooling with 87Rb and direct evaporation, exploiting the magnetic tuning of both inter- and intraspecies interactions at Feshbach resonances. We explore the tunability of the self-interactions by studying the expansion and the stability of the condensate. We find that a 39K condensate is interesting for future experiments requiring a weakly-interacting Bose gas.
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Affiliation(s)
- G Roati
- LENS and Dipartimento di Fisica, Università di Firenze, INFN and CNR-INFM, 50019 Sesto Fiorentino, Italy
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10
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Hart RA, Xu X, Legere R, Gibble K. A quantum scattering interferometer. Nature 2007; 446:892-5. [PMID: 17443182 DOI: 10.1038/nature05680] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Accepted: 02/08/2007] [Indexed: 11/08/2022]
Abstract
The collision of two ultracold atoms results in a quantum mechanical superposition of the two possible outcomes: each atom continues without scattering, and each atom scatters as an outgoing spherical wave with an s-wave phase shift. The magnitude of the s-wave phase shift depends very sensitively on the interaction between the atoms. Quantum scattering and the underlying phase shifts are vitally important in many areas of contemporary atomic physics, including Bose-Einstein condensates, degenerate Fermi gases, frequency shifts in atomic clocks and magnetically tuned Feshbach resonances. Precise experimental measurements of quantum scattering phase shifts have not been possible because the number of scattered atoms depends on the s-wave phase shifts as well as the atomic density, which cannot be measured precisely. Here we demonstrate a scattering experiment in which the quantum scattering phase shifts of individual atoms are detected using a novel atom interferometer. By performing an atomic clock measurement using only the scattered part of each atom's wavefunction, we precisely measure the difference of the s-wave phase shifts for the two clock states in a density-independent manner. Our method will enable direct and precise measurements of ultracold atom-atom interactions, and may be used to place stringent limits on the time variations of fundamental constants.
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Affiliation(s)
- Russell A Hart
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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11
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Szymaniec K, Chałupczak W, Tiesinga E, Williams CJ, Weyers S, Wynands R. Cancellation of the collisional frequency shift in caesium fountain clocks. PHYSICAL REVIEW LETTERS 2007; 98:153002. [PMID: 17501343 DOI: 10.1103/physrevlett.98.153002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Indexed: 05/15/2023]
Abstract
We have observed that the collisional frequency shift in primary caesium fountain clocks varies with the clock state population composition and, in particular, is zero for a given fraction of the |F=4,mF=0) atoms, depending on the initial cloud parameters. We present a theoretical model explaining our observations. The possibility of the collisional shift cancellation implies an improvement in the performance of caesium fountain standards and a simplification in their operation.
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Affiliation(s)
- K Szymaniec
- National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, United Kingdom
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12
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Kuklov AB. Unconventional strongly interacting bose-einstein condensates in optical lattices. PHYSICAL REVIEW LETTERS 2006; 97:110405. [PMID: 17025867 DOI: 10.1103/physrevlett.97.110405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Indexed: 05/12/2023]
Abstract
Feschbach resonances in a non-s-wave channel of two-component bosonic mixtures can induce atomic Bose-Einstein condensates with a nonzero orbital momentum in the optical lattice, if one component is in the Mott insulator state and the other is not. Such non-s-wave condensates break the symmetry of the lattice and, in some cases, time-reversal symmetry. They can be revealed in specific absorption imaging patterns.
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Affiliation(s)
- A B Kuklov
- Department of Physics, CSI, CUNY-Staten Island, New York, New York 10314, USA
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13
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Inouye S, Goldwin J, Olsen ML, Ticknor C, Bohn JL, Jin DS. Observation of heteronuclear Feshbach resonances in a mixture of bosons and fermions. PHYSICAL REVIEW LETTERS 2004; 93:183201. [PMID: 15525160 DOI: 10.1103/physrevlett.93.183201] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2004] [Indexed: 05/24/2023]
Abstract
Three magnetic-field induced heteronuclear Feshbach resonances were identified in collisions between bosonic 87Rb and fermionic 40K atoms in their absolute ground states. Strong inelastic loss from an optically trapped mixture was observed at the resonance positions of 492, 512, and 543+/-2 G. The magnetic-field locations of these resonances place a tight constraint on the triplet and singlet cross-species scattering lengths, yielding (-281+/-15)a(0) and (-54+/-12)a(0), respectively. The width of the loss feature at 543 G is 3.7+/-1.5 G wide; this broad Feshbach resonance should enable experimental control of the interspecies interactions.
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Affiliation(s)
- S Inouye
- JILA, National Institute of Standards and Technology, and University of Colorado, Boulder, CO 80309, USA
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14
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Buggle C, Léonard J, von Klitzing W, Walraven JTM. Interferometric determination of the s and d-wave scattering amplitudes in 87Rb. PHYSICAL REVIEW LETTERS 2004; 93:173202. [PMID: 15525074 DOI: 10.1103/physrevlett.93.173202] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Indexed: 05/24/2023]
Abstract
We demonstrate an interference method to determine the low-energy elastic scattering amplitudes of a quantum gas. We linearly accelerate two ultracold atomic clouds up to energies of 1.2 mK and observe the collision halo by direct imaging in free space. From the interference between s- and d- partial waves in the differential scattering pattern we extract the corresponding phase shifts. The method does not require knowledge of the atomic density. This allows us to infer accurate values for the s- and d-wave scattering amplitudes from the zero-energy limit up to the first Ramsauer minimum using only the van der Waals C6 coefficient as theoretical input. For the 87Rb triplet potential, the method reproduces the scattering length with an accuracy of 6%.
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Affiliation(s)
- Ch Buggle
- FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands
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15
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Eichhorn M, Mudrich M, Weidemüller M. Optical dipole trap inside a laser resonator. OPTICS LETTERS 2004; 29:1147-1149. [PMID: 15182014 DOI: 10.1364/ol.29.001147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We report the first realization, to our knowledge, of an optical dipole trap inside the active resonator of a laser. The concept, which is demonstrated with a CO2 laser (lambda = 10.6 microm), combines the advantages of optical power enhancement (up to 1.3-kW peak power) with the intrinsic stability of laser intensity as a result of the feedback of the active laser medium. Two kinds of trapping geometries are presented: a Gaussian trap in a transverse TEM00 mode and a boxlike transverse confinement in a superposition of transverse modes. In addition, longitudinal superlattices are created by two-frequency operation of the laser. Transfer efficiencies of up to 50% from a cesium magneto-optical trap are achieved. Storage times (7 = 0.3 s) are mainly limited by the background gas pressure. Possible sources of additional loss of atoms are discussed.
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Affiliation(s)
- Marc Eichhorn
- Max-Planck-Institut für Kernphysik, 69029 Heidelberg, Germany
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16
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Schmidt PO, Hensler S, Werner J, Griesmaier A, Görlitz A, Pfau T, Simoni A. Determination of the s-wave scattering length of chromium. PHYSICAL REVIEW LETTERS 2003; 91:193201. [PMID: 14611578 DOI: 10.1103/physrevlett.91.193201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2003] [Indexed: 05/24/2023]
Abstract
We have measured the deca-triplet s-wave scattering length of the bosonic chromium isotopes 52Cr and 50Cr. From the time constants for cross-dimensional thermalization in ultracold atomic samples, we have determined the magnitudes |a(52Cr)|=(170+/-39)a(0) and |a(50Cr)|=(40+/-15)a(0), where a(0)=0.053 nm. By measuring the rethermalization rate of 52Cr over a wide temperature range and comparing the temperature dependence with the effective-range theory and numerical single-channel calculations, we have obtained strong evidence that the sign of a(52Cr) is positive. Rescaling our 52Cr model potential to 50Cr strongly suggests that a(50Cr) is positive also.
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Affiliation(s)
- P O Schmidt
- 5. Physikalisches Institut, Universität Stuttgart, 70550 Stuttgart, Germany
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17
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Stock R, Deutsch IH, Bolda EL. Quantum state control via trap-induced shape resonance in ultracold atomic collisions. PHYSICAL REVIEW LETTERS 2003; 91:183201. [PMID: 14611281 DOI: 10.1103/physrevlett.91.183201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2003] [Indexed: 05/24/2023]
Abstract
We investigate controlled collisions between trapped but separated ultracold atoms. The interaction between atoms is treated self-consistently using an energy-dependent delta-function pseudopotential model, whose validity we establish. At a critical separation, a "trap-induced shape resonance" between molecular bound states and a vibrational eigenstate of the trap can occur. This resonance leads to an avoided crossing in the eigenspectrum as a function of separation. We investigate how this new resonance can be employed for quantum control.
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Affiliation(s)
- René Stock
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131, USA.
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18
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Weber T, Herbig J, Mark M, Nägerl HC, Grimm R. Three-body recombination at large scattering lengths in an ultracold atomic gas. PHYSICAL REVIEW LETTERS 2003; 91:123201. [PMID: 14525360 DOI: 10.1103/physrevlett.91.123201] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2003] [Indexed: 05/24/2023]
Abstract
We study three-body recombination in an optically trapped ultracold gas of cesium atoms with precise magnetic control of the s-wave scattering length a. At large positive values of a, we measure the dependence of the rate coefficient on a and confirm the theoretically predicted scaling proportional to a(4). Evidence of recombination heating indicates the formation of very weakly bound molecules in the last bound energy level.
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Affiliation(s)
- Tino Weber
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
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19
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Herbig J, Kraemer T, Mark M, Weber T, Chin C, Nägerl HC, Grimm R. Preparation of a pure molecular quantum gas. Science 2003; 301:1510-3. [PMID: 12934014 DOI: 10.1126/science.1088876] [Citation(s) in RCA: 335] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
An ultracold molecular quantum gas is created by application of a magnetic field sweep across a Feshbach resonance to a Bose-Einstein condensate of cesium atoms. The ability to separate the molecules from the atoms permits direct imaging of the pure molecular sample. Magnetic levitation enables study of the dynamics of the ensemble on extended time scales. We measured ultralow expansion energies in the range of a few nanokelvin for a sample of 3000 molecules. Our observations are consistent with the presence of a macroscopic molecular matter wave.
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Affiliation(s)
- Jens Herbig
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrabetae 25, 6020 Innsbruck, Austria
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20
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Regal CA, Ticknor C, Bohn JL, Jin DS. Tuning p-wave interactions in an ultracold Fermi gas of atoms. PHYSICAL REVIEW LETTERS 2003; 90:053201. [PMID: 12633351 DOI: 10.1103/physrevlett.90.053201] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2002] [Indexed: 05/24/2023]
Abstract
We have measured a p-wave Feshbach resonance in a single-component, ultracold Fermi gas of 40K atoms. We have used this resonance to enhance the normally suppressed p-wave collision cross section to values larger than the background s-wave cross section between 40K atoms in different spin states. In addition to the modification of two-body elastic processes, the resonance dramatically enhances three-body inelastic collisional loss.
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Affiliation(s)
- C A Regal
- JILA, National Institute of Standards and Technology, Boulder, Colorado 80309-0440, USA
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21
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Chin C, Kerman AJ, Vuletić V, Chu S. Sensitive detection of cold cesium molecules formed on Feshbach resonances. PHYSICAL REVIEW LETTERS 2003; 90:033201. [PMID: 12570487 DOI: 10.1103/physrevlett.90.033201] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2002] [Indexed: 05/24/2023]
Abstract
We observe the dynamic formation of quasibound Cs2 molecules near Feshbach resonances in a cold sample of atomic cesium. Using an external probe beam, more than 15 weakly coupled molecular states are detected with high sensitivity, whose collisional formation cross sections are as small as sigma=2 x 10(-16) cm(2). By modeling the molecule formation and dissociation processes with rate equations, we conclude that at an atomic density of 10(13) cm(-3) and temperature of 5 microK, more than 5(1)x10(5) Cs2 molecules in a single rovibrational state coexist with 10(8) Cs atoms in our trap.
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Affiliation(s)
- Cheng Chin
- Physics Department, Stanford University, Stanford, California 94305-4060, USA
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22
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Abstract
Bose-Einstein condensation of cesium atoms is achieved by evaporative cooling using optical trapping techniques. The ability to tune the interactions between the ultracold atoms by an external magnetic field is crucial to obtain the condensate and offers intriguing features for potential applications. We explore various regimes of condensate self-interaction (attractive, repulsive, and null interaction strength) and demonstrate properties of imploding, exploding, and non-interacting quantum matter.
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Affiliation(s)
- Tino Weber
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrabetae 25, 6020 Innsbruck, Austria
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23
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Marte A, Volz T, Schuster J, Dürr S, Rempe G, van Kempen EGM, Verhaar BJ. Feshbach resonances in rubidium 87: precision measurement and analysis. PHYSICAL REVIEW LETTERS 2002; 89:283202. [PMID: 12513142 DOI: 10.1103/physrevlett.89.283202] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2002] [Indexed: 05/24/2023]
Abstract
More than 40 Feshbach resonances in rubidium 87 are observed in the magnetic-field range between 0.5 and 1260 G for various spin mixtures in the lower hyperfine ground state. The Feshbach resonances are observed by monitoring the atom loss, and their positions are determined with an accuracy of 30 mG. In a detailed analysis, the resonances are identified and an improved set of model parameters for the rubidium interatomic potential is deduced. The elastic width of the broadest resonance at 1007 G is predicted to be significantly larger than the magnetic-field resolution of the apparatus. This demonstrates the potential for applications based on tuning the scattering length.
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Affiliation(s)
- A Marte
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
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Jochim S, Bartenstein M, Hendl G, Denschlag JH, Grimm R, Mosk A, Weidemüller M. Magnetic field control of elastic scattering in a cold gas of fermionic lithium atoms. PHYSICAL REVIEW LETTERS 2002; 89:273202. [PMID: 12513205 DOI: 10.1103/physrevlett.89.273202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2002] [Indexed: 05/24/2023]
Abstract
We study elastic collisions in an optically trapped spin mixture of fermionic lithium atoms in the presence of magnetic fields up to 1.5 kG by measuring evaporative loss. Our experiments confirm the expected magnetic tunability of the scattering length by showing the main features of elastic scattering according to recent calculations. We measure the zero crossing of the scattering length at 530(3) G which is associated with a predicted Feshbach resonance at approximately 850 G. Beyond the resonance we observe the expected large cross section in the triplet scattering regime.
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Affiliation(s)
- S Jochim
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
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Hechtfischer U, Williams CJ, Lange M, Linkemann J, Schwalm D, Wester R, Wolf A, Zajfman D. Photodissociation spectroscopy of stored CH+ ions: Detection, assignment, and close-coupled modeling of near-threshold Feshbach resonances. J Chem Phys 2002. [DOI: 10.1063/1.1513459] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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26
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Dieckmann K, Stan CA, Gupta S, Hadzibabic Z, Schunck CH, Ketterle W. Decay of an ultracold fermionic lithium gas near a Feshbach resonance. PHYSICAL REVIEW LETTERS 2002; 89:203201. [PMID: 12443476 DOI: 10.1103/physrevlett.89.203201] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2002] [Revised: 08/29/2002] [Indexed: 05/24/2023]
Abstract
We studied the magnetic field dependence of the inelastic decay of an ultracold, optically trapped fermionic 6Li gas of different spin compositions. The spin mixture of the two lowest hyperfine states showed two decay resonances at 550 and 680 G, consistent with the predicted Feshbach resonances for elastic s-wave collisions. The observed lifetimes of several hundred ms are much longer than the expected time for Cooper pair formation and the phase transition to superfluidity in the vicinity of the Feshbach resonance.
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Affiliation(s)
- K Dieckmann
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Amiot C, Dulieu O. The Cs2 ground electronic state by Fourier transform spectroscopy: Dispersion coefficients. J Chem Phys 2002. [DOI: 10.1063/1.1499122] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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28
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Loftus T, Regal CA, Ticknor C, Bohn JL, Jin DS. Resonant control of elastic collisions in an optically trapped fermi gas of atoms. PHYSICAL REVIEW LETTERS 2002; 88:173201. [PMID: 12005753 DOI: 10.1103/physrevlett.88.173201] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2001] [Indexed: 05/23/2023]
Abstract
We have loaded an ultracold gas of fermionic atoms into a far-off resonance optical dipole trap and precisely controlled the spin composition of the trapped gas. We have measured a magnetic-field Feshbach resonance between atoms in the two lowest energy spin states, /9/2,-9/2> and /9/2,-7/2>. The resonance peaks at a magnetic field of 201.5+/-1.4 G and has a width of 8.0+/-1.1 G. Using this resonance, we have changed the elastic collision cross section in the gas by nearly 3 orders of magnitude.
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Affiliation(s)
- T Loftus
- JILA, National Institute of Standards and Technology, University of Colorado, Boulder, Colorado 80309, USA
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29
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Burnett K, Julienne PS, Lett PD, Tiesinga E, Williams CJ. Quantum encounters of the cold kind. Nature 2002; 416:225-32. [PMID: 11894106 DOI: 10.1038/416225a] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Since the introduction of laser-cooling techniques for neutral atoms in the early 1980s, the study of collisional interactions between atoms and molecules has been extended to the regime of ultracold temperatures. With nanokelvin temperatures now attainable, our ability to probe the interactions, both experimentally and theoretically, has also progressed. Understanding of the subtle and often highly quantum-mechanical effects that are manifest at such low energies has advanced to the point where new precision measurements are matched by highly accurate theoretical calculations. Low-energy phenomena such as Bose-Einstein condensation and the photoassociation of atoms into bound molecules are now accurately described with no free parameters.
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Affiliation(s)
- Keith Burnett
- University of Oxford, Department of Physics, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
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30
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Abstract
This overview prefaces a collection of Insight review articles on the physics and applications of laser-cooled atoms. I will cast this work into a historical perspective in which laser cooling and trapping is seen as one of several research directions aimed at controlling the internal and external degrees of freedom of atoms and molecules.
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Affiliation(s)
- Steven Chu
- Physics Department, Stanford University, Stanford, California 94305-4060, USA
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31
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Dunjko V, Lorent V, Olshanii M. Bosons in cigar-shaped traps: Thomas-Fermi regime, Tonks-Girardeau regime, and in between. PHYSICAL REVIEW LETTERS 2001; 86:5413-5416. [PMID: 11415264 DOI: 10.1103/physrevlett.86.5413] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2001] [Indexed: 05/23/2023]
Abstract
We present a quantitative analysis of the experimental accessibility of the Tonks-Girardeau gas in present-day experiments with cigar-trapped alkalis. For this purpose we derive, using a Bethe ansatz generated local equation of state, a set of hydrostatic equations describing one-dimensional, delta-interacting Bose gases trapped in a harmonic potential. The resulting solutions cover the entire range of atomic densities.
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Affiliation(s)
- V Dunjko
- Department of Physics & Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA
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Leo PJ, Julienne PS, Mies FH, Williams CJ. Collisional frequency shifts in 133Cs fountain clocks. PHYSICAL REVIEW LETTERS 2001; 86:3743-3746. [PMID: 11329313 DOI: 10.1103/physrevlett.86.3743] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2000] [Indexed: 05/23/2023]
Abstract
We present a theoretical analysis of the density dependent frequency shift in Cs fountain clocks using the highly constrained binary collision model described by Leo et al. [Phys. Rev. Lett. 85, 2721 (2000)]. We predict a reversal in the clock shift at temperatures near 0.08 microK. Our results show that s waves dominate the collision process. However, as a consequence of the large scattering lengths in Cs the clock shift is strongly temperature dependent and does not reach a constant Wigner-law value until temperatures are less than 0.1 nK.
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Affiliation(s)
- P J Leo
- Atomic Physics Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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Leo PJ, Williams CJ, Julienne PS. Collision properties of ultracold 133Cs atoms. PHYSICAL REVIEW LETTERS 2000; 85:2721-2724. [PMID: 10991217 DOI: 10.1103/physrevlett.85.2721] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2000] [Indexed: 05/23/2023]
Abstract
We present a theoretical analysis of numerous magnetically tunable Feshbach resonances measured by Chin et al. [preceding Letter, Phys. Rev. Lett. 85, 2717 (2000)] at fields of up to 25 mT. This analysis provides the most accurate characterization of the collisional properties of ground state Cs atoms currently available and clearly shows, in contrast to previous work, that Bose-Einstein condensation of 133Cs cannot be ruled out. The X1Sigma(+)(g) and a(3)Sigma(u) scattering lengths are constrained to (280+/-10)a(0) and (2400+/-100)a(0), respectively ( 1a(0) = 0.052 917 7 nm), and the van der Waals C6 coefficient to 6890+/-35 a.u.(1 a.u. = 0.095 734 5 x10(-24) &Jdot;nm(6)).
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Affiliation(s)
- PJ Leo
- Atomic Physics Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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