1
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Pezzè L, Xhani K, Daix C, Grani N, Donelli B, Scazza F, Hernandez-Rajkov D, Kwon WJ, Del Pace G, Roati G. Stabilizing persistent currents in an atomtronic Josephson junction necklace. Nat Commun 2024; 15:4831. [PMID: 38844486 PMCID: PMC11156925 DOI: 10.1038/s41467-024-47759-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 04/10/2024] [Indexed: 06/09/2024] Open
Abstract
Arrays of Josephson junctions are at the forefront of research on quantum circuitry for quantum computing, simulation, and metrology. They provide a testing bed for exploring a variety of fundamental physical effects where macroscopic phase coherence, nonlinearities, and dissipative mechanisms compete. Here we realize finite-circulation states in an atomtronic Josephson junction necklace, consisting of a tunable array of tunneling links in a ring-shaped superfluid. We study the stability diagram of the atomic flow by tuning both the circulation and the number of junctions. We predict theoretically and demonstrate experimentally that the atomic circuit withstands higher circulations (corresponding to higher critical currents) by increasing the number of Josephson links. The increased stability contrasts with the trend of the superfluid fraction - quantified by Leggett's criterion - which instead decreases with the number of junctions and the corresponding density depletion. Our results demonstrate atomic superfluids in mesoscopic structured ring potentials as excellent candidates for atomtronics applications, with prospects towards the observation of non-trivial macroscopic superpositions of current states.
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Affiliation(s)
- Luca Pezzè
- Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche (CNR-INO), Largo Enrico Fermi 6, Firenze, 50125, Italy.
- European Laboratory for Nonlinear Spectroscopy (LENS), Via N. Carrara 1, Sesto Fiorentino, 50019, Italy.
- QSTAR, Largo Enrico Fermi 6, Firenze, 50125, Italy.
| | - Klejdja Xhani
- Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche (CNR-INO), Largo Enrico Fermi 6, Firenze, 50125, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), Via N. Carrara 1, Sesto Fiorentino, 50019, Italy
- QSTAR, Largo Enrico Fermi 6, Firenze, 50125, Italy
| | - Cyprien Daix
- European Laboratory for Nonlinear Spectroscopy (LENS), Via N. Carrara 1, Sesto Fiorentino, 50019, Italy
- Physics Department, University of Florence, Via Sansone 1, Sesto Fiorentino, 50019, Italy
| | - Nicola Grani
- Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche (CNR-INO), Largo Enrico Fermi 6, Firenze, 50125, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), Via N. Carrara 1, Sesto Fiorentino, 50019, Italy
- Physics Department, University of Florence, Via Sansone 1, Sesto Fiorentino, 50019, Italy
| | - Beatrice Donelli
- Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche (CNR-INO), Largo Enrico Fermi 6, Firenze, 50125, Italy
- QSTAR, Largo Enrico Fermi 6, Firenze, 50125, Italy
- University of Naples 'Federico II', Via Cinthia 21, Napoli, 80126, Italy
| | - Francesco Scazza
- Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche (CNR-INO), Largo Enrico Fermi 6, Firenze, 50125, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), Via N. Carrara 1, Sesto Fiorentino, 50019, Italy
- Physics Department, University of Trieste, Via A. Valerio 2, Trieste, 34127, Italy
| | - Diego Hernandez-Rajkov
- Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche (CNR-INO), Largo Enrico Fermi 6, Firenze, 50125, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), Via N. Carrara 1, Sesto Fiorentino, 50019, Italy
| | - Woo Jin Kwon
- Physics Department, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Giulia Del Pace
- European Laboratory for Nonlinear Spectroscopy (LENS), Via N. Carrara 1, Sesto Fiorentino, 50019, Italy
- Physics Department, University of Florence, Via Sansone 1, Sesto Fiorentino, 50019, Italy
| | - Giacomo Roati
- Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche (CNR-INO), Largo Enrico Fermi 6, Firenze, 50125, Italy.
- European Laboratory for Nonlinear Spectroscopy (LENS), Via N. Carrara 1, Sesto Fiorentino, 50019, Italy.
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2
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Schroff P, La Rooij A, Haller E, Kuhr S. Accurate holographic light potentials using pixel crosstalk modelling. Sci Rep 2023; 13:3252. [PMID: 36828926 PMCID: PMC9958060 DOI: 10.1038/s41598-023-30296-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 02/21/2023] [Indexed: 02/26/2023] Open
Abstract
Arbitrary light potentials have proven to be a valuable and versatile tool in many quantum information and quantum simulation experiments with ultracold atoms. Using a phase-modulating spatial light modulator (SLM), we generate arbitrary light potentials holographically with measured efficiencies between 15 and 40% and an accuracy of [Formula: see text] root-mean-squared error. Key to the high accuracy is the modelling of pixel crosstalk of the SLM on a sub-pixel scale which is relevant especially for large light potentials. We employ conjugate gradient minimisation to calculate the SLM phase pattern for a given target light potential after measuring the intensity and wavefront at the SLM. Further, we use camera feedback to reduce experimental errors, we remove optical vortices and investigate the difference between the angular spectrum method and the Fourier transform to simulate the propagation of light. Using a combination of all these techniques, we achieved more accurate and efficient light potentials compared to previous studies, and generated a series of potentials relevant for cold atom experiments.
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Affiliation(s)
- Paul Schroff
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, UK
| | - Arthur La Rooij
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, UK.
| | - Elmar Haller
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, UK
| | - Stefan Kuhr
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, UK
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3
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Jia F, Huang Z, Qiu L, Zhou R, Yan Y, Wang D. Expansion Dynamics of a Shell-Shaped Bose-Einstein Condensate. PHYSICAL REVIEW LETTERS 2022; 129:243402. [PMID: 36563247 DOI: 10.1103/physrevlett.129.243402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 11/18/2022] [Indexed: 06/17/2023]
Abstract
We report the creation of a shell BEC in the presence of Earth's gravity with immiscible dual-species BECs of sodium and rubidium atoms. After minimizing the displacement between the centers of mass of the two BECs with a magic-wavelength optical dipole trap, the interspecies repulsive interaction ensures the formation of a closed shell of sodium atoms with its center filled by rubidium atoms. Releasing the double BEC together from the trap, we observe explosion of the filled shell accompanied by energy transfer from the inner BEC to the shell BEC. With the inner BEC removed, we obtain a hollow shell BEC that shows self-interference as a manifestation of implosion. Our results pave an alternative way for investigating many of the intriguing physics offered by shell BECs.
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Affiliation(s)
- Fan Jia
- Department of Physics, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Zerong Huang
- Department of Physics, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Liyuan Qiu
- Department of Physics, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Rongzi Zhou
- Department of Physics, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Yangqian Yan
- Department of Physics, The Chinese University of Hong Kong, Hong Kong SAR, China
- The Chinese University of Hong Kong Shenzhen Research Institute, 518057 Shenzhen, China
| | - Dajun Wang
- Department of Physics, The Chinese University of Hong Kong, Hong Kong SAR, China
- The Chinese University of Hong Kong Shenzhen Research Institute, 518057 Shenzhen, China
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4
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Gautier R, Guessoum M, Sidorenkov LA, Bouton Q, Landragin A, Geiger R. Accurate measurement of the Sagnac effect for matter waves. SCIENCE ADVANCES 2022; 8:eabn8009. [PMID: 35687688 PMCID: PMC9187224 DOI: 10.1126/sciadv.abn8009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 04/27/2022] [Indexed: 06/04/2023]
Abstract
A rotating interferometer with paths that enclose a physical area exhibits a phase shift proportional to this area and to the rotation rate of the frame. Understanding the origin of this so-called Sagnac effect has played a key role in the establishment of the theory of relativity and has pushed for the development of precision optical interferometers. The fundamental importance of the Sagnac effect motivated the realization of experiments to test its validity for waves beyond optical, but precision measurements remained a challenge. Here, we report the accurate test of the Sagnac effect for matter waves, by using a Cesium atom interferometer featuring a geometrical area of 11 cm2 and two sensitive axes of measurements. We measure the phase shift induced by Earth's rotation and find agreement with the theoretical prediction at an accuracy level of 25 parts per million. Beyond the importance for fundamental physics, our work opens practical applications in seismology and geodesy.
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5
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Josephson-Like Oscillations in Toroidal Spinor Bose–Einstein Condensates: A Prospective Symmetry Probe. Symmetry (Basel) 2022. [DOI: 10.3390/sym14050867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/10/2022] Open
Abstract
Josephson junctions are essential ingredients in the superconducting circuits used in many [*]current existing quantum technologies. [*]Additionally, ultracold atomic quantum gases [*]have also become essential platforms to study superfluidity. Here, we explore the analogy between superconductivity and superfluidity [*], studying a superfluid version of the Josephson effect due to a thin barrier in a quasi-1D toroidal spinor BEC to present an intriguing effect caused by a thin finite barrier in a quasi-one-dimensional toroidal spinor Bose–Einstein condensate (BEC). In this system, the atomic current density flowing through the edges of the barrier [*]is analogous to the electrical current through a Josephson junction in a superconductor, even in the case without a net flow oscillates, such as the electrical current through a Josephson junction in a superconductor, but in our case, there is no current circulation through the barrier. We also [*]discuss show how the nontrivial broken-symmetry states of spinor BECs [*]may change the structure of [*]the equivalent Josephson this Josephson-like current[*], creating the possibility to probe the spinor symmetry, solely using measurements of this superfluid current.
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6
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Cai Y, Allman DG, Sabharwal P, Wright KC. Persistent Currents in Rings of Ultracold Fermionic Atoms. PHYSICAL REVIEW LETTERS 2022; 128:150401. [PMID: 35499879 DOI: 10.1103/physrevlett.128.150401] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 12/31/2021] [Accepted: 03/01/2022] [Indexed: 06/14/2023]
Abstract
We have produced persistent currents of ultracold fermionic atoms trapped in a ring, with lifetimes greater than 10 sec in the strongly interacting regime. These currents remain stable well into the BCS regime at sufficiently low temperature. We drive a circulating BCS superfluid into the normal phase and back by changing the interaction strength and find that the probability for quantized superflow to reappear is remarkably insensitive to the time spent in the normal phase and the minimum interaction strength. After ruling out spontaneous current formation for our experimental conditions, we argue that the reappearance of superflow is due to weak damping of normal currents in this limit. These results establish that ultracold fermionic atoms with tunable interactions can be used to create matter-wave circuits similar to those previously created with weakly interacting bosonic atoms.
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Affiliation(s)
- Yanping Cai
- Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, New Hampshire 03755, USA
| | - Daniel G Allman
- Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, New Hampshire 03755, USA
| | - Parth Sabharwal
- Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, New Hampshire 03755, USA
| | - Kevin C Wright
- Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, New Hampshire 03755, USA
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7
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Pâţu OI, Averin DV. Temperature-Dependent Periodicity of the Persistent Current in Strongly Interacting Systems. PHYSICAL REVIEW LETTERS 2022; 128:096801. [PMID: 35302823 DOI: 10.1103/physrevlett.128.096801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
The persistent current in small isolated rings enclosing magnetic flux is the current circulating in equilibrium in the absence of an external excitation. While initially studied in superconducting and normal metals, recently, atomic persistent currents have been generated in ultracold gases spurring a new wave of theoretical investigations. Nevertheless, our understanding of the persistent currents in interacting systems is far from complete, especially at finite temperatures. Here we consider the fermionic one-dimensional Hubbard model and show that in the strong-interacting limit, the current can change its flux period and sign (diamagnetic or paramagnetic) as a function of temperature, features that cannot be explained within the single-particle or Luttinger liquid techniques. Also, the magnitude of the current can counterintuitively increase with temperature, in addition to presenting different rates of decay depending on the polarization of the system. Our work highlights the properties of the strongly interacting multicomponent systems that are missed by conventional approximation techniques, but can be important for the interpretation of experiments on persistent currents in ultracold gases.
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Affiliation(s)
- Ovidiu I Pâţu
- Institute for Space Sciences, Bucharest-Măgurele R 077125, Romania
| | - Dmitri V Averin
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
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8
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Kumar P, Biswas T, Feliz K, Kanamoto R, Chang MS, Jha AK, Bhattacharya M. Cavity Optomechanical Sensing and Manipulation of an Atomic Persistent Current. PHYSICAL REVIEW LETTERS 2021; 127:113601. [PMID: 34558916 DOI: 10.1103/physrevlett.127.113601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
This theoretical work initiates contact between two frontier disciplines of physics, namely, atomic superfluid rotation and cavity optomechanics. It considers an annular Bose-Einstein condensate, which exhibits dissipationless flow and is a paradigm of rotational quantum physics, inside a cavity excited by optical fields carrying orbital angular momentum. It provides the first platform that can sense ring Bose-Einstein condensate rotation with minimal destruction, in situ and in real time, unlike demonstrated techniques, all of which involve fully destructive measurement. It also shows how light can actively manipulate rotating matter waves by optomechanically entangling persistent currents. Our work opens up a novel and useful direction in the sensing and manipulation of atomic superflow.
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Affiliation(s)
- Pardeep Kumar
- School of Physics and Astronomy, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, New York 14623, USA
| | - Tushar Biswas
- School of Physics and Astronomy, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, New York 14623, USA
| | - Kristian Feliz
- School of Physics and Astronomy, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, New York 14623, USA
| | - Rina Kanamoto
- Department of Physics, Meiji University, Kawasaki, Kanagawa 214-8571, Japan
| | - M-S Chang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Department of Physics and Center for Quantum Technology, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Anand K Jha
- Department of Physics, Indian Institute of Technology, Kanpur, Uttar Pradesh 208016, India
| | - M Bhattacharya
- School of Physics and Astronomy, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, New York 14623, USA
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9
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Pepino RA. Advances in Atomtronics. ENTROPY (BASEL, SWITZERLAND) 2021; 23:534. [PMID: 33925410 PMCID: PMC8147053 DOI: 10.3390/e23050534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 04/25/2021] [Accepted: 04/26/2021] [Indexed: 11/23/2022]
Abstract
Atomtronics is a relatively new subfield of atomic physics that aims to realize the device behavior of electronic components in ultracold atom-optical systems. The fact that these systems are coherent makes them particularly interesting since, in addition to current, one can impart quantum states onto the current carriers themselves or perhaps perform quantum computational operations on them. After reviewing the fundamental ideas of this subfield, we report on the theoretical and experimental progress made towards developing externally-driven and closed loop devices. The functionality and potential applications for these atom analogs to electronic and spintronic systems is also discussed.
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Affiliation(s)
- Ron A Pepino
- Department of Chemistry, Biochemistry and Physics Florida Southern College, Lakeland, FL 33801, USA
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10
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Guan Q, Ome MKH, Bersano TM, Mossman S, Engels P, Blume D. Nonexponential Tunneling due to Mean-Field-Induced Swallowtails. PHYSICAL REVIEW LETTERS 2020; 125:213401. [PMID: 33274984 DOI: 10.1103/physrevlett.125.213401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 10/27/2020] [Indexed: 06/12/2023]
Abstract
Typically, energy levels change without bifurcating in response to a change of a control parameter. Bifurcations can lead to loops or swallowtails in the energy spectrum. The simplest quantum Hamiltonian that supports swallowtails is a nonlinear 2×2 Hamiltonian with nonzero off-diagonal elements and diagonal elements that depend on the population difference of the two states. This work implements such a Hamiltonian experimentally using ultracold atoms in a moving one-dimensional optical lattice. Self-trapping and nonexponential tunneling probabilities, a hallmark signature of band structures that support swallowtails, are observed. The good agreement between theory and experiment validates the optical lattice system as a powerful platform to study, e.g., Josephson junction physics and superfluidity in ring-shaped geometries.
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Affiliation(s)
- Q Guan
- Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, 440 W. Brooks Street, Norman, Oklahoma 73019, USA
- Center for Quantum Research and Technology, The University of Oklahoma, 440 W. Brooks Street, Norman, Oklahoma 73019, USA
| | - M K H Ome
- Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814, USA
| | - T M Bersano
- Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814, USA
| | - S Mossman
- Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814, USA
| | - P Engels
- Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814, USA
| | - D Blume
- Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, 440 W. Brooks Street, Norman, Oklahoma 73019, USA
- Center for Quantum Research and Technology, The University of Oklahoma, 440 W. Brooks Street, Norman, Oklahoma 73019, USA
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11
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Ryu C, Samson EC, Boshier MG. Quantum interference of currents in an atomtronic SQUID. Nat Commun 2020; 11:3338. [PMID: 32620901 PMCID: PMC7335076 DOI: 10.1038/s41467-020-17185-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 06/15/2020] [Indexed: 11/18/2022] Open
Abstract
Quantum interference of currents is the most important and well known quantum phenomenon in a conventional superconducting quantum interference device (SQUID). Here, we report the observation of quantum interference of currents in an atomtronic SQUID. Analogous to a conventional SQUID, currents flowing through two junctions in an atomtronic SQUID interfere due to the phase difference from rotation. This interference results in modulation of critical currents. This modulation was observed for three different radii with clear modulation periods which were measured to be consistent with fundamental rotation rates. This observation shows the possibility of studying various interesting SQUID physics with an atomtronic SQUID and especially, macroscopic quantum phenomena with currents may be realized with an atomtronic SQUID toward the goal of quantum metrology of rotation sensing. Quantum interference of currents was first observed in a superconducting quantum interference device (SQUID). Here, the authors demonstrate quantum interference of currents in the atomtronic analog of a SQUID using Bose-Einstein condensates of 87Rb atoms.
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Affiliation(s)
- C Ryu
- Physics Division, Los Alamos National Laboratory, Los Alamos, NM, USA.
| | - E C Samson
- Physics Division, Los Alamos National Laboratory, Los Alamos, NM, USA.,Department of Physics, Miami University, Oxford, OH, USA
| | - M G Boshier
- Physics Division, Los Alamos National Laboratory, Los Alamos, NM, USA
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12
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Henderson VA, Johnson MYH, Kale YB, Griffin PF, Riis E, Arnold AS. Optical characterisation of micro-fabricated Fresnel zone plates for atomic waveguides. OPTICS EXPRESS 2020; 28:9072-9081. [PMID: 32225520 DOI: 10.1364/oe.388897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 02/29/2020] [Indexed: 06/10/2023]
Abstract
We optically assess Fresnel zone plates (FZPs) that are designed to guide cold atoms. Imaging of various ring patterns produced by the FZPs gives an average RMS error in the brightest part of the ring of 3% with respect to trap depth. This residue is attributed to the imaging system, incident beam shape and FZP manufacturing tolerances. Axial propagation of the potentials is presented experimentally and through numerical simulations, illustrating prospects for atom guiding without requiring light sheets.
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13
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Pérez-Obiol A, Cheon T. Bose-Einstein condensate confined in a one-dimensional ring stirred with a rotating delta link. Phys Rev E 2020; 101:022212. [PMID: 32168626 DOI: 10.1103/physreve.101.022212] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 01/31/2020] [Indexed: 11/07/2022]
Abstract
We consider a Bose-Einstein condensate with repulsive interactions confined in a one-dimensional ring where a Dirac δ is rotating at constant speed. The spectrum of stationary solutions in the δ comoving frame is analyzed in terms of the nonlinear coupling, δ velocity, and δ strength, which may take positive and negative values. It is organized into a set of energy levels conforming a multiple swallowtail structure in parameter space, consisting of bright solitons, gray and dark solitonic trains, and vortex states. Analytical expressions in terms of Jacobi elliptic functions are provided for the wave functions and chemical potentials. We compute the critical velocities and perform a Bogoliubov analysis for the ground state and first few excited levels, establishing possible adiabatic transitions between the stationary and stable solutions. A set of adiabatic cycles is proposed in which gray and dark solitons, and vortex states of arbitrary quantized angular momenta, are obtained from the ground state by setting and unsetting a rotating δ. These cycles are reproduced by simulations of the time-dependent Gross-Pitaevskii equation with a rotating Gaussian link.
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Affiliation(s)
- Axel Pérez-Obiol
- Laboratory of Physics, Kochi University of Technology, Tosa Yamada, Kochi 782-8502, Japan
| | - Taksu Cheon
- Laboratory of Physics, Kochi University of Technology, Tosa Yamada, Kochi 782-8502, Japan
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14
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Xhani K, Neri E, Galantucci L, Scazza F, Burchianti A, Lee KL, Barenghi CF, Trombettoni A, Inguscio M, Zaccanti M, Roati G, Proukakis NP. Critical Transport and Vortex Dynamics in a Thin Atomic Josephson Junction. PHYSICAL REVIEW LETTERS 2020; 124:045301. [PMID: 32058733 DOI: 10.1103/physrevlett.124.045301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Indexed: 06/10/2023]
Abstract
We study the onset of dissipation in an atomic Josephson junction between Fermi superfluids in the molecular Bose-Einstein condensation limit of strong attraction. Our simulations identify the critical population imbalance and the maximum Josephson current delimiting dissipationless and dissipative transport, in quantitative agreement with recent experiments. We unambiguously link dissipation to vortex ring nucleation and dynamics, demonstrating that quantum phase slips are responsible for the observed resistive current. Our work directly connects microscopic features with macroscopic dissipative transport, providing a comprehensive description of vortex ring dynamics in three-dimensional inhomogeneous constricted superfluids at zero and finite temperatures.
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Affiliation(s)
- K Xhani
- Joint Quantum Centre (JQC) Durham-Newcastle, School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
- European Laboratory for Non-Linear Spectroscopy (LENS), Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - E Neri
- Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - L Galantucci
- Joint Quantum Centre (JQC) Durham-Newcastle, School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - F Scazza
- European Laboratory for Non-Linear Spectroscopy (LENS), Università di Firenze, 50019 Sesto Fiorentino, Italy
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
| | - A Burchianti
- European Laboratory for Non-Linear Spectroscopy (LENS), Università di Firenze, 50019 Sesto Fiorentino, Italy
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
| | - K-L Lee
- Joint Quantum Centre (JQC) Durham-Newcastle, School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - C F Barenghi
- Joint Quantum Centre (JQC) Durham-Newcastle, School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - A Trombettoni
- CNR-IOM DEMOCRITOS Simulation Center and SISSA, Via Bonomea 265, I-34136 Trieste, Italy
| | - M Inguscio
- European Laboratory for Non-Linear Spectroscopy (LENS), Università di Firenze, 50019 Sesto Fiorentino, Italy
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
- Department of Engineering, Campus Bio-Medico University of Rome, 00128 Rome, Italy
| | - M Zaccanti
- European Laboratory for Non-Linear Spectroscopy (LENS), Università di Firenze, 50019 Sesto Fiorentino, Italy
- Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
| | - G Roati
- European Laboratory for Non-Linear Spectroscopy (LENS), Università di Firenze, 50019 Sesto Fiorentino, Italy
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), 50019 Sesto Fiorentino, Italy
| | - N P Proukakis
- Joint Quantum Centre (JQC) Durham-Newcastle, School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
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15
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Kochetov BA, Chelpanova OG, Tuz VR, Yakimenko AI. Spontaneous and engineered transformations of topological structures in nonlinear media with gain and loss. Phys Rev E 2020; 100:062202. [PMID: 31962499 DOI: 10.1103/physreve.100.062202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Indexed: 11/07/2022]
Abstract
In contrast to conservative systems, in nonlinear media with gain and loss the dynamics of localized topological structures exhibit many unique features that can be controlled externally. We propose a robust mechanism to perform topological transformations changing characteristics of dissipative vortices and their complexes in a controllable way. We show that a properly chosen potential carries out the evolution of dissipative structures to regime with spontaneous transformation of the topological excitations or drives generation of vortices with control over the topological charge.
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Affiliation(s)
- B A Kochetov
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, International Center of Future Science, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - O G Chelpanova
- Department of Physics, Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, Kyiv 01601, Ukraine
| | - V R Tuz
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, International Center of Future Science, Jilin University, 2699 Qianjin Street, Changchun 130012, China.,Institute of Radio Astronomy, National Academy of Sciences of Ukraine, 4, Mystetstv Street, Kharkiv 61002, Ukraine
| | - A I Yakimenko
- Department of Physics, Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, Kyiv 01601, Ukraine
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Gauthier G, Szigeti SS, Reeves MT, Baker M, Bell TA, Rubinsztein-Dunlop H, Davis MJ, Neely TW. Quantitative Acoustic Models for Superfluid Circuits. PHYSICAL REVIEW LETTERS 2019; 123:260402. [PMID: 31951434 DOI: 10.1103/physrevlett.123.260402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Indexed: 06/10/2023]
Abstract
We experimentally realize a highly tunable superfluid oscillator circuit in a quantum gas of ultracold atoms and develop and verify a simple lumped-element description of this circuit. At low oscillator currents, we demonstrate that the circuit is accurately described as a Helmholtz resonator, a fundamental element of acoustic circuits. At larger currents, the breakdown of the Helmholtz regime is heralded by a turbulent shedding of vortices and density waves. Although a simple phase-slip model offers qualitative insights into the circuit's resistive behavior, our results indicate deviations from the phase-slip model. A full understanding of the dissipation in superfluid circuits will thus require the development of empirical models of the turbulent dynamics in this system, as have been developed for classical acoustic systems.
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Affiliation(s)
- Guillaume Gauthier
- ARC Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
| | - Stuart S Szigeti
- ARC Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
- Department of Quantum Science, Research School of Physics, The Australian National University, Canberra 2601, Australia
| | - Matthew T Reeves
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
| | - Mark Baker
- ARC Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
| | - Thomas A Bell
- ARC Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
| | - Halina Rubinsztein-Dunlop
- ARC Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
| | - Matthew J Davis
- ARC Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
| | - Tyler W Neely
- ARC Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
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Polo J, Dubessy R, Pedri P, Perrin H, Minguzzi A. Oscillations and Decay of Superfluid Currents in a One-Dimensional Bose Gas on a Ring. PHYSICAL REVIEW LETTERS 2019; 123:195301. [PMID: 31765184 DOI: 10.1103/physrevlett.123.195301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 07/22/2019] [Indexed: 06/10/2023]
Abstract
We study the time evolution of a supercurrent imprinted on a one-dimensional ring of interacting bosons in the presence of a defect created by a localized barrier. Depending on interaction strength and temperature, we identify various dynamical regimes where the current oscillates, is self-trapped, or decays with time. We show that the dynamics is captured by a dual Josephson model and involve phase slips of thermal or quantum nature.
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Affiliation(s)
- Juan Polo
- University Grenoble Alpes, CNRS, LPMMC, 38000 Grenoble, France
- Quantum Systems Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Romain Dubessy
- Laboratoire de Physique des Lasers, CNRS, Université Paris 13, Sorbonne Paris Cité, 99 Avenue J.-B. Clément, F-93430 Villetaneuse, France
| | - Paolo Pedri
- Laboratoire de Physique des Lasers, CNRS, Université Paris 13, Sorbonne Paris Cité, 99 Avenue J.-B. Clément, F-93430 Villetaneuse, France
| | - Hélène Perrin
- Laboratoire de Physique des Lasers, CNRS, Université Paris 13, Sorbonne Paris Cité, 99 Avenue J.-B. Clément, F-93430 Villetaneuse, France
| | - Anna Minguzzi
- University Grenoble Alpes, CNRS, LPMMC, 38000 Grenoble, France
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18
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Symmetry Breaking in Interacting Ring-Shaped Superflows of Bose–Einstein Condensates. Symmetry (Basel) 2019. [DOI: 10.3390/sym11101312] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We demonstrate that the evolution of superflows in interacting persistent currents of ultracold gases is strongly affected by symmetry breaking of the quantum vortex dynamics. We study counter-propagating superflows in a system of two parallel rings in regimes of weak (a Josephson junction with tunneling through the barrier) and strong (rings merging across a reduced barrier) interactions. For the weakly interacting toroidal Bose–Einstein condensates, formation of rotational fluxons (Josephson vortices) is associated with spontaneous breaking of the rotational symmetry of the tunneling superflows. The influence of a controllable symmetry breaking on the final state of the merging counter-propagating superflows is investigated in the framework of a weakly dissipative mean-field model. It is demonstrated that the population imbalance between the merging flows and the breaking of the underlying rotational symmetry can drive the double-ring system to final states with different angular momenta.
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Chen PK, Liu LR, Tsai MJ, Chiu NC, Kawaguchi Y, Yip SK, Chang MS, Lin YJ. Rotating Atomic Quantum Gases with Light-Induced Azimuthal Gauge Potentials and the Observation of the Hess-Fairbank Effect. PHYSICAL REVIEW LETTERS 2018; 121:250401. [PMID: 30608846 DOI: 10.1103/physrevlett.121.250401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Indexed: 06/09/2023]
Abstract
We demonstrate synthetic azimuthal gauge potentials for Bose-Einstein condensates from engineering atom-light couplings. The gauge potential is created by adiabatically loading the condensate into the lowest energy Raman-dressed state, achieving a coreless vortex state. The azimuthal gauge potentials act as effective rotations and are tunable by the Raman coupling and detuning. We characterize the spin textures of the dressed states, in agreements with the theory. The lowest energy dressed state is stable with a 4.5-s half-atom-number-fraction lifetime. In addition, we exploit the azimuthal gauge potential to demonstrate the Hess-Fairbank effect, the analogue of Meissner effect in superconductors. The atoms in the absolute ground state has a zero quasiangular momentum and transits into a polar-core vortex when the synthetic magnetic flux is tuned to exceed a critical value. Our demonstration serves as a paradigm to create topological excitations by tailoring atom-light interactions where both types of SO(3) vortices in the |⟨F[over →]⟩|=1 manifold, coreless vortices and polar-core vortices, are created in our experiment. The gauge field in the stationary Hamiltonian opens a path to investigating rotation properties of atomic superfluids under thermal equilibrium.
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Affiliation(s)
- P-K Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - L-R Liu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - M-J Tsai
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - N-C Chiu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Y Kawaguchi
- Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan
| | - S-K Yip
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
- National Center for Theoretical Sciences, Hsinchu 300, Taiwan
| | - M-S Chang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Y-J Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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Surface Excitations, Shape Deformation, and the Long-Time Behavior in a Stirred Bose–Einstein Condensate. CONDENSED MATTER 2018. [DOI: 10.3390/condmat3040041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The surface excitations, shape deformation, and the formation of persistent current for a Gaussian obstacle potential rotating in a highly oblate Bose–Einstein condensate (BEC) are investigated. A vortex dipole can be produced and trapped in the center of the stirrer even for the slow motion of the stirring beam. When the angular velocity of the obstacle is above some critical value, the condensate shape can be deformed remarkably at the corresponding rotation frequency followed by surface wave excitations. After a long enough time, a small number of vortices are found to be either trapped in the condensate or pinned by the obstacle, and a vortex dipole or several vortices can be trapped at the beam center, which provides another way to manipulate the vortex.
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21
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Chen HR, Lin KY, Chen PK, Chiu NC, Wang JB, Chen CA, Huang PP, Yip SK, Kawaguchi Y, Lin YJ. Spin-Orbital-Angular-Momentum Coupled Bose-Einstein Condensates. PHYSICAL REVIEW LETTERS 2018; 121:113204. [PMID: 30265085 DOI: 10.1103/physrevlett.121.113204] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Indexed: 06/08/2023]
Abstract
We demonstrate coupling between the atomic spin- and orbital-angular momentum (OAM) of the atom's center-of-mass motion in a Bose-Einstein condensate (BEC). The coupling is induced by Raman-dressing lasers with a Laguerre-Gaussian beam and creates coreless vortices in an F=1 ^{87}Rb spinor BEC. We observe correlations between spin and OAM in the dressed state and characterize the spin texture; the result is in good agreement with the theory. In the presence of the Raman field, our dressed state is stable for 0.1 s or longer, and it decays due to collision-induced relaxation. As we turn off the Raman beams, the vortex cores in the bare spin |m_{F}=1⟩ and |-1⟩ split. These spin-OAM coupled systems with the Raman-dressing approach have great potential for exploring new topological textures and quantum states.
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Affiliation(s)
- H-R Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - K-Y Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - P-K Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - N-C Chiu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - J-B Wang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - C-A Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - P-P Huang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - S-K Yip
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - Yuki Kawaguchi
- Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan
| | - Y-J Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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22
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Polo J, Ahufinger V, Hekking FWJ, Minguzzi A. Damping of Josephson Oscillations in Strongly Correlated One-Dimensional Atomic Gases. PHYSICAL REVIEW LETTERS 2018; 121:090404. [PMID: 30230871 DOI: 10.1103/physrevlett.121.090404] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Indexed: 06/08/2023]
Abstract
We study Josephson oscillations of two strongly correlated one-dimensional bosonic clouds separated by a localized barrier. Using a quantum-Langevin approach and the exact Tonks-Girardeau solution in the impenetrable-boson limit, we determine the dynamical evolution of the particle-number imbalance, displaying an effective damping of the Josephson oscillations which depends on barrier height, interaction strength, and temperature. We show that the damping originates from the quantum and thermal fluctuations intrinsically present in the strongly correlated gas. Because of the density-phase duality of the model, the same results apply to particle-current oscillations in a one-dimensional ring where a weak barrier couples different angular momentum states.
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Affiliation(s)
- J Polo
- Univ. Grenoble Alpes, CNRS, LPMMC, F-38000 Grenoble, France
| | - V Ahufinger
- Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
| | - F W J Hekking
- Univ. Grenoble Alpes, CNRS, LPMMC, F-38000 Grenoble, France
| | - A Minguzzi
- Univ. Grenoble Alpes, CNRS, LPMMC, F-38000 Grenoble, France
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23
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Burchianti A, Scazza F, Amico A, Valtolina G, Seman JA, Fort C, Zaccanti M, Inguscio M, Roati G. Connecting Dissipation and Phase Slips in a Josephson Junction between Fermionic Superfluids. PHYSICAL REVIEW LETTERS 2018; 120:025302. [PMID: 29376686 DOI: 10.1103/physrevlett.120.025302] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Indexed: 06/07/2023]
Abstract
We study the emergence of dissipation in an atomic Josephson junction between weakly coupled superfluid Fermi gases. We find that vortex-induced phase slippage is the dominant microscopic source of dissipation across the Bose-Einstein condensate-Bardeen-Cooper-Schrieffer crossover. We explore different dynamical regimes by tuning the bias chemical potential between the two superfluid reservoirs. For small excitations, we observe dissipation and phase coherence to coexist, with a resistive current followed by well-defined Josephson oscillations. We link the junction transport properties to the phase-slippage mechanism, finding that vortex nucleation is primarily responsible for the observed trends of conductance and critical current. For large excitations, we observe the irreversible loss of coherence between the two superfluids, and transport cannot be described only within an uncorrelated phase-slip picture. Our findings open new directions for investigating the interplay between dissipative and superfluid transport in strongly correlated Fermi systems, and general concepts in out-of-equilibrium quantum systems.
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Affiliation(s)
- A Burchianti
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (INO-CNR), 50019 Sesto Fiorentino, Italy
- LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - F Scazza
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (INO-CNR), 50019 Sesto Fiorentino, Italy
- LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - A Amico
- LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - G Valtolina
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (INO-CNR), 50019 Sesto Fiorentino, Italy
- LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - J A Seman
- Instituto de Fisica, Universidad Nacional Autónoma de México, 01000 Ciudad de México, Mexico
| | - C Fort
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (INO-CNR), 50019 Sesto Fiorentino, Italy
- LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - M Zaccanti
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (INO-CNR), 50019 Sesto Fiorentino, Italy
- LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - M Inguscio
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (INO-CNR), 50019 Sesto Fiorentino, Italy
- LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - G Roati
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (INO-CNR), 50019 Sesto Fiorentino, Italy
- LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
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24
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Andrijauskas T, Spielman IB, Juzeliūnas G. Topological lattice using multi-frequency radiation. NEW JOURNAL OF PHYSICS 2018; 20:10.1088/1367-2630/aab7a3. [PMID: 30996650 PMCID: PMC6463519 DOI: 10.1088/1367-2630/aab7a3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We describe anoveltechniqueforcreatinganartificialmagneticfieldforultracoldatomsusinga periodicallypulsedpairofcounterpropagatingRamanlasersthatdrivetransitionsbetween a pair of internal atomic spin states: a multi-frequency coupling term. In conjunction with a magnetic field gradient, this dynamically generates a rectangular lattice with a non-staggered magnetic flux. For a wide range of parameters, the resulting Bloch bands have non-trivial topology, reminiscent of Landau levels, as quantified by their Chern numbers.
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Affiliation(s)
- Tomas Andrijauskas
- Institute of Theoretical Physics and Astronomy, Vilnius University, Saulėtekio 3, LT-10222 Vilnius, Lithuania
| | - I B Spielman
- Joint Quantum Institute, University of Maryland, College Park,MD20742-4111, United States of America
- National Institute of Standards and Technology, Gaithersburg,MD20899, United States of America
| | - Gediminas Juzeliūnas
- Institute of Theoretical Physics and Astronomy, Vilnius University, Saulėtekio 3, LT-10222 Vilnius, Lithuania
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25
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D'Errico C, Abbate SS, Modugno G. Quantum phase slips: from condensed matter to ultracold quantum gases. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:20160425. [PMID: 29084890 PMCID: PMC5665781 DOI: 10.1098/rsta.2016.0425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/25/2017] [Indexed: 06/07/2023]
Abstract
Quantum phase slips (QPS) are the primary excitations in one-dimensional superfluids and superconductors at low temperatures. They have been well characterized in most condensed-matter systems, and signatures of their existence have been recently observed in superfluids based on quantum gases too. In this review, we briefly summarize the main results obtained on the investigation of phase slips from superconductors to quantum gases. In particular, we focus our attention on recent experimental results of the dissipation in one-dimensional Bose superfluids flowing along a shallow periodic potential, which show signatures of QPS.This article is part of the themed issue 'Breakdown of ergodicity in quantum systems: from solids to synthetic matter'.
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Affiliation(s)
- C D'Errico
- Istituto Nazionale di Ottica, CNR, 50019 Sesto Fiorentino, Italy
- LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - S Scaffidi Abbate
- LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
| | - G Modugno
- Istituto Nazionale di Ottica, CNR, 50019 Sesto Fiorentino, Italy
- LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy
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26
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Krinner S, Esslinger T, Brantut JP. Two-terminal transport measurements with cold atoms. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:343003. [PMID: 28749788 DOI: 10.1088/1361-648x/aa74a1] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In recent years, the ability of cold atom experiments to explore condensed-matter-related questions has dramatically progressed. Transport experiments, in particular, have expanded to the point in which conductance and other transport coefficients can now be measured in a way that is directly analogous to solid-state physics, extending cold-atom-based quantum simulations into the domain of quantum electronic devices. In this topical review, we describe the transport experiments performed with cold gases in the two-terminal configuration, with an emphasis on the specific features of cold atomic gases compared to solid-state physics. We present the experimental techniques and the main experimental findings, focusing on-but not restricted to-the recent experiments performed by our group. We finally discuss the perspectives opened up by this approach, the main technical and conceptual challenges for future developments, and potential applications in quantum simulation for transport phenomena and mesoscopic physics problems.
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Affiliation(s)
- Sebastian Krinner
- Institute for Quantum Electronics, ETH Zurich, 8093 Zurich, Switzerland
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27
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Martin AM, Marchant NG, O'Dell DHJ, Parker NG. Vortices and vortex lattices in quantum ferrofluids. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:103004. [PMID: 28145899 DOI: 10.1088/1361-648x/aa53a6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The experimental realization of quantum-degenerate Bose gases made of atoms with sizeable magnetic dipole moments has created a new type of fluid, known as a quantum ferrofluid, which combines the extraordinary properties of superfluidity and ferrofluidity. A hallmark of superfluids is that they are constrained to rotate through vortices with quantized circulation. In quantum ferrofluids the long-range dipolar interactions add new ingredients by inducing magnetostriction and instabilities, and also affect the structural properties of vortices and vortex lattices. Here we give a review of the theory of vortices in dipolar Bose-Einstein condensates, exploring the interplay of magnetism with vorticity and contrasting this with the established behaviour in non-dipolar condensates. We cover single vortex solutions, including structure, energy and stability, vortex pairs, including interactions and dynamics, and also vortex lattices. Our discussion is founded on the mean-field theory provided by the dipolar Gross-Pitaevskii equation, ranging from analytic treatments based on the Thomas-Fermi (hydrodynamic) and variational approaches to full numerical simulations. Routes for generating vortices in dipolar condensates are discussed, with particular attention paid to rotating condensates, where surface instabilities drive the nucleation of vortices, and lead to the emergence of rich and varied vortex lattice structures. We also present an outlook, including potential extensions to degenerate Fermi gases, quantum Hall physics, toroidal systems and the Berezinskii-Kosterlitz-Thouless transition.
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Affiliation(s)
- A M Martin
- School of Physics, University of Melbourne, Victoria 3010, Australia
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28
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Franke-Arnold S. Optical angular momentum and atoms. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:20150435. [PMID: 28069766 PMCID: PMC5247479 DOI: 10.1098/rsta.2015.0435] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/23/2016] [Indexed: 05/24/2023]
Abstract
Any coherent interaction of light and atoms needs to conserve energy, linear momentum and angular momentum. What happens to an atom's angular momentum if it encounters light that carries orbital angular momentum (OAM)? This is a particularly intriguing question as the angular momentum of atoms is quantized, incorporating the intrinsic spin angular momentum of the individual electrons as well as the OAM associated with their spatial distribution. In addition, a mechanical angular momentum can arise from the rotation of the entire atom, which for very cold atoms is also quantized. Atoms therefore allow us to probe and access the quantum properties of light's OAM, aiding our fundamental understanding of light-matter interactions, and moreover, allowing us to construct OAM-based applications, including quantum memories, frequency converters for shaped light and OAM-based sensors.This article is part of the themed issue 'Optical orbital angular momentum'.
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Affiliation(s)
- Sonja Franke-Arnold
- SUPA and School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
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29
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Ragole S, Taylor JM. Interacting Atomic Interferometry for Rotation Sensing Approaching the Heisenberg Limit. PHYSICAL REVIEW LETTERS 2016; 117:203002. [PMID: 27886499 DOI: 10.1103/physrevlett.117.203002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Indexed: 06/06/2023]
Abstract
Atom interferometers provide exquisite measurements of the properties of noninertial frames. While atomic interactions are typically detrimental to good sensing, efforts to harness entanglement to improve sensitivity remain tantalizing. Here we explore the role of interactions in an analogy between atomic gyroscopes and SQUIDs, motivated by recent experiments realizing ring-shaped traps for ultracold atoms. We explore the one-dimensional limit of these ring systems with a moving weak barrier, such as that provided by a blue-detuned laser beam. In this limit, we employ Luttinger liquid theory and find an analogy with the superconducting phase-slip qubit, in which the topological charge associated with persistent currents can be put into superposition. In particular, we find that strongly interacting atoms in such a system could be used for precision rotation sensing. We compare the performance of this new sensor to an equivalent noninteracting atom interferometer, and find improvements in sensitivity and bandwidth beyond the atomic shot-noise limit.
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Affiliation(s)
- Stephen Ragole
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
- Joint Center for Quantum Information and Computer Science, University of Maryland, College Park, Maryland 20742, USA
| | - Jacob M Taylor
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
- Joint Center for Quantum Information and Computer Science, University of Maryland, College Park, Maryland 20742, USA
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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30
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Menchon-Enrich R, Benseny A, Ahufinger V, Greentree AD, Busch T, Mompart J. Spatial adiabatic passage: a review of recent progress. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:074401. [PMID: 27245462 DOI: 10.1088/0034-4885/79/7/074401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Adiabatic techniques are known to allow for engineering quantum states with high fidelity. This requirement is currently of large interest, as applications in quantum information require the preparation and manipulation of quantum states with minimal errors. Here we review recent progress on developing techniques for the preparation of spatial states through adiabatic passage, particularly focusing on three state systems. These techniques can be applied to matter waves in external potentials, such as cold atoms or electrons, and to classical waves in waveguides, such as light or sound.
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Affiliation(s)
- R Menchon-Enrich
- Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
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Wood AA, McKellar BHJ, Martin AM. Persistent Superfluid Flow Arising from the He-McKellar-Wilkens Effect in Molecular Dipolar Condensates. PHYSICAL REVIEW LETTERS 2016; 116:250403. [PMID: 27391706 DOI: 10.1103/physrevlett.116.250403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Indexed: 06/06/2023]
Abstract
We show that the He-McKellar-Wilkens effect can induce a persistent flow in a Bose-Einstein condensate of polar molecules confined in a toroidal trap, with the dipolar interaction mediated via an electric dipole moment. For Bose-Einstein condensates of atoms with a magnetic dipole moment, we show that although it is theoretically possible to induce persistent flow via the Aharonov-Casher effect, the strength of the electric field required is prohibitive. We also outline an experimental geometry tailored specifically for observing the He-McKellar-Wilkens effect in toroidally trapped condensates.
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Affiliation(s)
- A A Wood
- School of Physics, University of Melbourne, Victoria 3010, Australia
| | - B H J McKellar
- ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, University of Melbourne, Victoria 3010, Australia
| | - A M Martin
- School of Physics, University of Melbourne, Victoria 3010, Australia
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Eckel S, Lee JG, Jendrzejewski F, Lobb CJ, Campbell GK, Hill WT. Contact resistance and phase slips in mesoscopic superfluid atom transport. PHYSICAL REVIEW. A 2016; 93:10.1103/PhysRevA.93.063619. [PMID: 36733381 PMCID: PMC9890817 DOI: 10.1103/physreva.93.063619] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We have experimentally measured transport of superfluid, bosonic atoms in a mesoscopic system: a small channel connecting two large reservoirs. Starting far from equilibrium (superfluid in a single reservoir), we observe first resistive flow transitioning at a critical current into superflow, characterized by oscillations. We reproduce this full evolution with a simple electronic circuit model. We compare our fitted conductance to two different microscopic phenomenological models. We also show that the oscillations are consistent with LC oscillations as estimated by the kinetic inductance and effective capacitance in our system. Our experiment provides an attractive platform to begin to probe the mesoscopic transport properties of a dilute, superfluid, Bose gas.
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33
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Nonlinear Phenomena of Ultracold Atomic Gases in Optical Lattices: Emergence of Novel Features in Extended States. ENTROPY 2016. [DOI: 10.3390/e18040118] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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34
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Valtolina G, Burchianti A, Amico A, Neri E, Xhani K, Seman JA, Trombettoni A, Smerzi A, Zaccanti M, Inguscio M, Roati G. Josephson effect in fermionic superfluids across the BEC-BCS crossover. Science 2015; 350:1505-8. [DOI: 10.1126/science.aac9725] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 11/13/2015] [Indexed: 11/02/2022]
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Piazza F, Ritsch H. Self-Ordered Limit Cycles, Chaos, and Phase Slippage with a Superfluid inside an Optical Resonator. PHYSICAL REVIEW LETTERS 2015; 115:163601. [PMID: 26550874 DOI: 10.1103/physrevlett.115.163601] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Indexed: 06/05/2023]
Abstract
We study dynamical phases of a driven Bose-Einstein condensate coupled to the light field of a high-Q optical cavity. For high field seeking atoms at red detuning the system is known to show a transition from a spatially homogeneous steady state to a self-ordered regular lattice exhibiting superradiant scattering into the cavity. For blue atom pump detuning the particles are repelled from the maxima of the light-induced optical potential suppressing scattering. We show that this generates a new dynamical instability of the self-ordered phase, leading to the appearance of self-ordered stable limit cycles characterized by large amplitude self-sustained oscillations of both the condensate density and cavity field. The limit cycles evolve into chaotic behavior by period doubling. Large amplitude oscillations of the condensate are accompanied by phase slippage through soliton nucleation at a rate that increases in the chaotic regime. Different from a superfluid in a closed setup, this driven dissipative superfluid is not destroyed by the proliferation of solitons since kinetic energy is removed through cavity losses.
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Affiliation(s)
- Francesco Piazza
- Institut für Theoretische Physik, Universität Innsbruck, A-6020 Innsbruck, Austria
| | - Helmut Ritsch
- Institut für Theoretische Physik, Universität Innsbruck, A-6020 Innsbruck, Austria
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36
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Arwas G, Vardi A, Cohen D. Superfluidity and Chaos in low dimensional circuits. Sci Rep 2015; 5:13433. [PMID: 26315272 PMCID: PMC4551964 DOI: 10.1038/srep13433] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 07/27/2015] [Indexed: 11/09/2022] Open
Abstract
The hallmark of superfluidity is the appearance of "vortex states" carrying a quantized metastable circulating current. Considering a unidirectional flow of particles in a ring, at first it appears that any amount of scattering will randomize the velocity, as in the Drude model, and eventually the ergodic steady state will be characterized by a vanishingly small fluctuating current. However, Landau and followers have shown that this is not always the case. If elementary excitations (e.g. phonons) have higher velocity than that of the flow, simple kinematic considerations imply metastability of the vortex state: the energy of the motion cannot dissipate into phonons. On the other hand if this Landau criterion is violated the circulating current can decay. Below we show that the standard Landau and Bogoliubov superfluidity criteria fail in low-dimensional circuits. Proper determination of the superfluidity regime-diagram must account for the crucial role of chaos, an ingredient missing from the conventional stability analysis. Accordingly, we find novel types of superfluidity, associated with irregular or chaotic or breathing vortex states.
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Affiliation(s)
- Geva Arwas
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Amichay Vardi
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Doron Cohen
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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A new type of half-quantum circulation in a macroscopic polariton spinor ring condensate. Proc Natl Acad Sci U S A 2015; 112:2676-81. [PMID: 25730875 DOI: 10.1073/pnas.1424549112] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We report the observation of coherent circulation in a macroscopic Bose-Einstein condensate of polaritons in a ring geometry. Because they are spinor condensates, half-quanta are allowed in where there is a phase rotation of π in connection with a polarization vector rotation of π around a closed path. This half-quantum behavior is clearly seen in the experimental observations of the polarization rotation around the ring. In our ring geometry, the half-quantum state that we see is one in which the handedness of the spin flips from one side of the ring to the other side in addition to the rotation of the linear polarization component; such a state is allowed in a ring geometry but will not occur in a simply connected geometry. This state is lower in energy than a half-quantum state with no change of the spin direction and corresponds to a superposition of two different elementary half-quantum states. The direction of circulation of the flow around the ring fluctuates randomly between clockwise and counterclockwise from one shot to the next; this fluctuation corresponds to spontaneous breaking of time-reversal symmetry in the system. This type of macroscopic polariton ring condensate allows for the possibility of direct control of the circulation to excite higher quantized states and the creation of Josephson junction tunneling barriers.
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Turpin A, Polo J, Loiko YV, Küber J, Schmaltz F, Kalkandjiev TK, Ahufinger V, Birkl G, Mompart J. Blue-detuned optical ring trap for Bose-Einstein condensates based on conical refraction. OPTICS EXPRESS 2015; 23:1638-1650. [PMID: 25835921 DOI: 10.1364/oe.23.001638] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a novel approach for the optical manipulation of neutral atoms in annular light structures produced by the phenomenon of conical refraction occurring in biaxial optical crystals. For a beam focused to a plane behind the crystal, the focal plane exhibits two concentric bright rings enclosing a ring of null intensity called the Poggendorff ring. We demonstrate both theoretically and experimentally that the Poggendorff dark ring of conical refraction is confined in three dimensions by regions of higher intensity. We derive the positions of the confining intensity maxima and minima and discuss the application of the Poggendorff ring for trapping ultra-cold atoms using the repulsive dipole force of blue-detuned light. We give analytical expressions for the trapping frequencies and potential depths along both the radial and the axial directions. Finally, we present realistic numerical simulations of the dynamics of a 87Rb Bose-Einstein condensate trapped inside the Poggendorff ring which are in good agreement with corresponding experimental results.
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Goldman N, Juzeliūnas G, Öhberg P, Spielman IB. Light-induced gauge fields for ultracold atoms. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2014; 77:126401. [PMID: 25422950 DOI: 10.1088/0034-4885/77/12/126401] [Citation(s) in RCA: 179] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Gauge fields are central in our modern understanding of physics at all scales. At the highest energy scales known, the microscopic universe is governed by particles interacting with each other through the exchange of gauge bosons. At the largest length scales, our Universe is ruled by gravity, whose gauge structure suggests the existence of a particle-the graviton-that mediates the gravitational force. At the mesoscopic scale, solid-state systems are subjected to gauge fields of different nature: materials can be immersed in external electromagnetic fields, but they can also feature emerging gauge fields in their low-energy description. In this review, we focus on another kind of gauge field: those engineered in systems of ultracold neutral atoms. In these setups, atoms are suitably coupled to laser fields that generate effective gauge potentials in their description. Neutral atoms 'feeling' laser-induced gauge potentials can potentially mimic the behavior of an electron gas subjected to a magnetic field, but also, the interaction of elementary particles with non-Abelian gauge fields. Here, we review different realized and proposed techniques for creating gauge potentials-both Abelian and non-Abelian-in atomic systems and discuss their implication in the context of quantum simulation. While most of these setups concern the realization of background and classical gauge potentials, we conclude with more exotic proposals where these synthetic fields might be made dynamical, in view of simulating interacting gauge theories with cold atoms.
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Affiliation(s)
- N Goldman
- College de France, 11 place Marcelin Berthelot & Laboratoire Kastler Brossel, CNRS, UPMC, ENS, 24 rue Lhomond, 75005 Paris, France
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40
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Sinuco-León GA, Burrows KA, Arnold AS, Garraway BM. Inductively guided circuits for ultracold dressed atoms. Nat Commun 2014; 5:5289. [PMID: 25348163 PMCID: PMC4220492 DOI: 10.1038/ncomms6289] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Accepted: 09/17/2014] [Indexed: 11/23/2022] Open
Abstract
Recent progress in optics, atomic physics and material science has paved the way to study quantum effects in ultracold atomic alkali gases confined to non-trivial geometries. Multiply connected traps for cold atoms can be prepared by combining inhomogeneous distributions of DC and radio-frequency electromagnetic fields with optical fields that require complex systems for frequency control and stabilization. Here we propose a flexible and robust scheme that creates closed quasi-one-dimensional guides for ultracold atoms through the ‘dressing’ of hyperfine sublevels of the atomic ground state, where the dressing field is spatially modulated by inductive effects over a micro-engineered conducting loop. Remarkably, for commonly used atomic species (for example, 7Li and 87Rb), the guide operation relies entirely on controlling static and low-frequency fields in the regimes of radio-frequency and microwave frequencies. This novel trapping scheme can be implemented with current technology for micro-fabrication and electronic control. Ultracold atomic gases show interesting quantum effects but the traps needed to study them are complex and often unwieldy. This study proposes a flexible and robust trapping scheme based on a spatially modulated atomic dressing field, created from an inductive loop, that traps atoms in one-dimensional guides.
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Affiliation(s)
- German A Sinuco-León
- Department of Physics and Astronomy, University of Sussex, Falmer, Brighton BN1 9QH, UK
| | - Kathryn A Burrows
- Department of Physics and Astronomy, University of Sussex, Falmer, Brighton BN1 9QH, UK
| | - Aidan S Arnold
- Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG, UK
| | - Barry M Garraway
- Department of Physics and Astronomy, University of Sussex, Falmer, Brighton BN1 9QH, UK
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41
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Lee JG, Hill WT. Spatial shaping for generating arbitrary optical dipole traps for ultracold degenerate gases. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:103106. [PMID: 25362370 DOI: 10.1063/1.4895676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present two spatial-shaping approaches - phase and amplitude - for creating two-dimensional optical dipole potentials for ultracold neutral atoms. When combined with an attractive or repulsive Gaussian sheet formed by an astigmatically focused beam, atoms are trapped in three dimensions resulting in planar confinement with an arbitrary network of potentials - a free-space atom chip. The first approach utilizes an adaptation of the generalized phase-contrast technique to convert a phase structure embedded in a beam after traversing a phase mask, to an identical intensity profile in the image plane. Phase masks, and a requisite phase-contrast filter, can be chemically etched into optical material (e.g., fused silica) or implemented with spatial light modulators; etching provides the highest quality while spatial light modulators enable prototyping and realtime structure modification. This approach was demonstrated on an ensemble of thermal atoms. Amplitude shaping is possible when the potential structure is made as an opaque mask in the path of a dipole trap beam, followed by imaging the shadow onto the plane of the atoms. While much more lossy, this very simple and inexpensive approach can produce dipole potentials suitable for containing degenerate gases. High-quality amplitude masks can be produced with standard photolithography techniques. Amplitude shaping was demonstrated on a Bose-Einstein condensate.
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Affiliation(s)
- Jeffrey G Lee
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| | - W T Hill
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
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42
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Corman L, Chomaz L, Bienaimé T, Desbuquois R, Weitenberg C, Nascimbène S, Dalibard J, Beugnon J. Quench-induced supercurrents in an annular Bose gas. PHYSICAL REVIEW LETTERS 2014; 113:135302. [PMID: 25302899 DOI: 10.1103/physrevlett.113.135302] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Indexed: 06/04/2023]
Abstract
We create supercurrents in annular two-dimensional Bose gases through a temperature quench of the normal-to-superfluid phase transition. We detect the magnitude and the direction of these supercurrents by measuring spiral patterns resulting from the interference of the cloud with a central reference disk. These measurements demonstrate the stochastic nature of the supercurrents. We further measure their distribution for different quench times and compare it with predictions based on the Kibble-Zurek mechanism.
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Affiliation(s)
- L Corman
- Laboratoire Kastler Brossel, CNRS, UPMC, ENS, Collège de France, 24 Rue Lhomond, 75231 Paris Cedex 05, France
| | - L Chomaz
- Laboratoire Kastler Brossel, CNRS, UPMC, ENS, Collège de France, 24 Rue Lhomond, 75231 Paris Cedex 05, France and Collège de France, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - T Bienaimé
- Laboratoire Kastler Brossel, CNRS, UPMC, ENS, Collège de France, 24 Rue Lhomond, 75231 Paris Cedex 05, France
| | - R Desbuquois
- Institut für Quantenelektronics, ETH Zurich, 8093 Zurich, Switzerland
| | - C Weitenberg
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, D-22761 Hamburg, Germany
| | - S Nascimbène
- Laboratoire Kastler Brossel, CNRS, UPMC, ENS, Collège de France, 24 Rue Lhomond, 75231 Paris Cedex 05, France
| | - J Dalibard
- Laboratoire Kastler Brossel, CNRS, UPMC, ENS, Collège de France, 24 Rue Lhomond, 75231 Paris Cedex 05, France and Collège de France, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - J Beugnon
- Laboratoire Kastler Brossel, CNRS, UPMC, ENS, Collège de France, 24 Rue Lhomond, 75231 Paris Cedex 05, France
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43
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Jendrzejewski F, Eckel S, Murray N, Lanier C, Edwards M, Lobb CJ, Campbell GK. Resistive flow in a weakly interacting Bose-Einstein condensate. PHYSICAL REVIEW LETTERS 2014; 113:045305. [PMID: 25105631 DOI: 10.1103/physrevlett.113.045305] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Indexed: 06/03/2023]
Abstract
We report the direct observation of resistive flow through a weak link in a weakly interacting atomic Bose-Einstein condensate. Two weak links separate our ring-shaped superfluid atomtronic circuit into two distinct regions, a source and a drain. Motion of these weak links allows for creation of controlled flow between the source and the drain. At a critical value of the weak link velocity, we observe a transition from superfluid flow to superfluid plus resistive flow. Working in the hydrodynamic limit, we observe a conductivity that is 4 orders of magnitude larger than previously reported conductivities for a Bose-Einstein condensate with a tunnel junction. Good agreement with zero-temperature Gross-Pitaevskii simulations and a phenomenological model based on phase slips indicate that the creation of excitations plays an important role in the resulting conductivity. Our measurements of resistive flow elucidate the microscopic origin of the dissipation and pave the way for more complex atomtronic devices.
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Affiliation(s)
- F Jendrzejewski
- Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, Maryland 20899, USA
| | - S Eckel
- Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, Maryland 20899, USA
| | - N Murray
- Department of Physics, Georgia Southern University, Statesboro, Georgia 30460-8031, USA
| | - C Lanier
- Department of Physics, Georgia Southern University, Statesboro, Georgia 30460-8031, USA
| | - M Edwards
- Department of Physics, Georgia Southern University, Statesboro, Georgia 30460-8031, USA
| | - C J Lobb
- Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, Maryland 20899, USA
| | - G K Campbell
- Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, Maryland 20899, USA
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44
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Cominotti M, Rossini D, Rizzi M, Hekking F, Minguzzi A. Optimal persistent currents for interacting bosons on a ring with a gauge field. PHYSICAL REVIEW LETTERS 2014; 113:025301. [PMID: 25062201 DOI: 10.1103/physrevlett.113.025301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Indexed: 06/03/2023]
Abstract
We study persistent currents for interacting one-dimensional bosons on a tight ring trap, subjected to a rotating barrier potential, which induces an artificial U(1) gauge field. We show that, at intermediate interactions, the persistent current response is maximal, due to a subtle interplay of effects due to the barrier, the interaction, and quantum fluctuations. These results are relevant for ongoing experiments with ultracold atomic gases on mesoscopic rings.
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Affiliation(s)
- Marco Cominotti
- Université Grenoble Alpes, LPMMC, F-38000 Grenoble, France and CNRS, LPMMC, F-38000 Grenoble, France
| | - Davide Rossini
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, I-56126 Pisa, Italy
| | - Matteo Rizzi
- Institut für Physik, Johannes-Gutenberg-Universität Mainz, Staudingerweg 7, D-55099 Mainz, Germany
| | - Frank Hekking
- Université Grenoble Alpes, LPMMC, F-38000 Grenoble, France and CNRS, LPMMC, F-38000 Grenoble, France
| | - Anna Minguzzi
- Université Grenoble Alpes, LPMMC, F-38000 Grenoble, France and CNRS, LPMMC, F-38000 Grenoble, France
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45
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del Campo A, Boshier MG, Saxena A. Bent waveguides for matter-waves: supersymmetric potentials and reflectionless geometries. Sci Rep 2014; 4:5274. [PMID: 24919423 PMCID: PMC4053736 DOI: 10.1038/srep05274] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 05/23/2014] [Indexed: 11/09/2022] Open
Abstract
Non-zero curvature in a waveguide leads to the appearance of an attractive quantum potential which crucially affects the dynamics in matter-wave circuits. Using methods of supersymmetric quantum mechanics, pairs of bent waveguides are found whose geometry-induced potentials share the same scattering properties. As a result, reflectionless waveguides, dual to the straight waveguide, are identified. Strictly isospectral waveguides are also found by modulating the depth of the trapping potential. Numerical simulations are used to demonstrate the efficiency of these approaches in tailoring and controlling curvature-induced quantum-mechanical effects.
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Affiliation(s)
- Adolfo del Campo
- 1] Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA [2] Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Malcolm G Boshier
- Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Avadh Saxena
- 1] Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA [2] Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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46
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Sütő A. Galilean invariance in confined quantum systems: implications for spectral gaps, superfluid flow, and periodic order. PHYSICAL REVIEW LETTERS 2014; 112:095301. [PMID: 24655263 DOI: 10.1103/physrevlett.112.095301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Indexed: 06/03/2023]
Abstract
Galilean invariance leaves its imprint on the energy spectrum and eigenstates of N quantum particles, bosons, or fermions, confined in a bounded domain. It endows the spectrum with a recurrent structure, which in capillaries or elongated traps of length L and cross-section area s(⊥) leads to spectral gaps n(2)h(2)s(⊥)ρ/(2 mL) at wave numbers 2nπs(⊥)ρ, where ρ is the number density and m is the particle mass. In zero temperature superfluids, in toroidal geometries, it causes the quantization of the flow velocity with the quantum h/(mL) or that of the circulation along the toroid with the known quantum h/m. Adding a "friction" potential, which breaks Galilean invariance, the Hamiltonian can have a superfluid ground state at low flow velocities but not above a critical velocity, which may be different from the velocity of sound. In the limit of infinite N and L, if N/L = s(⊥)ρ is kept fixed, translation invariance is broken, and the center of mass has a periodic distribution, while superfluidity persists at low flow velocities. This conclusion holds for the Lieb-Liniger model.
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Affiliation(s)
- András Sütő
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest, Hungary
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47
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Davis MJ, Helmerson K. Condensed-matter physics: history matters for a stirred superfluid. Nature 2014; 506:166-7. [PMID: 24522595 DOI: 10.1038/506166a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Matthew J Davis
- School of Mathematics and Physics, University of Queensland, St Lucia, Queensland 4072, Australia
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48
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Eckel S, Lee JG, Jendrzejewski F, Murray N, Clark CW, Lobb CJ, Phillips WD, Edwards M, Campbell GK. Hysteresis in a quantized superfluid ‘atomtronic’ circuit. Nature 2014; 506:200-3. [DOI: 10.1038/nature12958] [Citation(s) in RCA: 255] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 12/12/2013] [Indexed: 11/09/2022]
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50
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Ryu C, Blackburn PW, Blinova AA, Boshier MG. Experimental realization of Josephson junctions for an atom SQUID. PHYSICAL REVIEW LETTERS 2013; 111:205301. [PMID: 24289693 DOI: 10.1103/physrevlett.111.205301] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Indexed: 06/02/2023]
Abstract
We report the creation of a pair of Josephson junctions on a toroidal dilute gas Bose-Einstein condensate (BEC), a configuration that is the cold atom analog of the well-known dc superconducting quantum interference device (SQUID). We observe Josephson effects, measure the critical current of the junctions, and find dynamic behavior that is in good agreement with the simple Josephson equations for a tunnel junction with the ideal sinusoidal current-phase relation expected for the parameters of the experiment. The junctions and toroidal trap are created with the painted potential, a time-averaged optical dipole potential technique which will allow scaling to more complex BEC circuit geometries than the single atom-SQUID case reported here. Since rotation plays the same role in the atom SQUID as magnetic field does in the dc SQUID magnetometer, the device has potential as a compact rotation sensor.
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Affiliation(s)
- C Ryu
- P-21, Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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