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Yar A. Hexagonal warping effects on Bloch oscillations in proximitized Rashba systems. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:335704. [PMID: 38780062 DOI: 10.1088/1361-648x/ad49f8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 05/10/2024] [Indexed: 05/25/2024]
Abstract
Bloch oscillations (BOs) in Rashba systems, taking into account the effects of hexagonal warping and proximity-induced band gap, are reported. We find that in addition to real-space trajectories, the group and Berry velocities of Bloch electrons exhibit novel BOs which strongly depend on the crystal momentum. This oscillatory motion is affected significantly by variations in the strength of hexagonal warping and the proximity-induced band gap, originating from the substantial changes in the energy spectrum induced by these factors. In addition, it is shown that the Bloch oscillations are modified considerably under the influence of applied uniform in-plane electric and transverse magnetic fields, which allow for a geometric visualization of the Bloch dynamics. Interestingly, when the system is subjected to these fields simultaneously, it undergoes a dynamic phase transition between confined and de-confined states. This phase transition is tuned by the relative strength of the applied fields and is further influenced by variations in the strength of hexagonal warping and proximity-induced band gap. The appearance of such a transition is attributed to the interplay between the external fields and the intrinsic properties of the crystal lattice. Moreover, we find that the direct-current drift velocity shows negative differential conductivity, which is a characteristic feature of the BO regime.
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Affiliation(s)
- Abdullah Yar
- Department of Physics, Kohat University of Science and Technology, Kohat 26000, Khyber Pakhtunkhwa, Pakistan
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2
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Zhang Z, Ning S, Zhong H, Belić MR, Zhang Y, Feng Y, Liang S, Zhang Y, Xiao M. Experimental demonstration of optical Bloch oscillation in electromagnetically induced photonic lattices. FUNDAMENTAL RESEARCH 2022. [DOI: 10.1016/j.fmre.2021.08.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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3
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Determination of the fine-structure constant with an accuracy of 81 parts per trillion. Nature 2020; 588:61-65. [DOI: 10.1038/s41586-020-2964-7] [Citation(s) in RCA: 151] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 10/16/2020] [Indexed: 11/09/2022]
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4
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Ribeiro P, Lazarides A, Haque M. Many-Body Quantum Dynamics of Initially Trapped Systems due to a Stark Potential: Thermalization versus Bloch Oscillations. PHYSICAL REVIEW LETTERS 2020; 124:110603. [PMID: 32242703 DOI: 10.1103/physrevlett.124.110603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 01/13/2020] [Accepted: 02/20/2020] [Indexed: 06/11/2023]
Abstract
We analyze the dynamics of an initially trapped cloud of interacting quantum particles on a lattice under a linear (Stark) potential. We reveal a dichotomy: initially trapped interacting systems possess features typical of both many-body-localized and thermalizing systems. We consider both fermions (t-V model) and bosons (Bose-Hubbard model). For the zero and infinite interaction limits, both systems are integrable: we provide analytic solutions in terms of the moments of the initial cloud shape and clarify how the recurrent dynamics (many-body Bloch oscillations) depends on the initial state. Away from the integrable points, we identify and explain the timescale at which Bloch oscillations decohere.
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Affiliation(s)
- Pedro Ribeiro
- CeFEMA, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal
- Beijing Computational Science Research Center, Beijing 100193, China
- Max Planck Institute for the Physics of Complex Systems, Nothnitzer Strasse 38, 01187 Dresden, Germany
| | - Achilleas Lazarides
- Max Planck Institute for the Physics of Complex Systems, Nothnitzer Strasse 38, 01187 Dresden, Germany
- Interdisciplinary Centre for Mathematical Modelling and Department of Mathematical Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, United Kingdom
| | - Masudul Haque
- Max Planck Institute for the Physics of Complex Systems, Nothnitzer Strasse 38, 01187 Dresden, Germany
- Department of Theoretical Physics, Maynooth University, Maynooth, County Kildare, Ireland
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5
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Experimental Evidence of Rainbow Trapping and Bloch Oscillations of Torsional Waves in Chirped Metallic Beams. Sci Rep 2019; 9:1860. [PMID: 30755629 PMCID: PMC6372627 DOI: 10.1038/s41598-018-37842-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 12/11/2018] [Indexed: 11/25/2022] Open
Abstract
The Bloch oscillations (BO) and the rainbow trapping (RT) are two apparently unrelated phenomena, the former arising in solid state physics and the latter in metamaterials. A Bloch oscillation, on the one hand, is a counter-intuitive effect in which electrons start to oscillate in a crystalline structure when a static electric field is applied. This effect has been observed not only in solid state physics but also in optical and acoustical structured systems since a static electric field can be mimicked by a chirped structure. The RT, on the other hand, is a phenomenon in which the speed of a wave packet is slowed down in a dielectric structure; different colors then arrive to different depths within the structure thus separating the colors also in time. Here we show experimentally the emergence of both phenomena studying the propagation of torsional waves in chirped metallic beams. Experiments are performed in three aluminum beams in which different structures were machined: one periodic and two chirped. For the smaller value of the chirping parameter the wave packets, with different central frequencies, are back-scattered at different positions inside the corrugated beam; the packets with higher central frequencies being the ones with larger penetration depths. This behavior represents the mechanical analogue of the rainbow trapping effect. This phenomenon is the precursor of the mechanical Bloch oscillations, which are here demonstrated for a larger value of the chirping parameter. It is observed that the oscillatory behavior observed at small values of the chirp parameter is rectified according to the penetration length of the wave packet.
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Sun Y, Leykam D, Nenni S, Song D, Chen H, Chong YD, Chen Z. Observation of Valley Landau-Zener-Bloch Oscillations and Pseudospin Imbalance in Photonic Graphene. PHYSICAL REVIEW LETTERS 2018; 121:033904. [PMID: 30085826 DOI: 10.1103/physrevlett.121.033904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 05/04/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate intervalley Bloch oscillation (BO) and Landau-Zener tunneling (LZT) in an optically induced honeycomb lattice with a refractive-index gradient. Unlike previously observed BO in a gapped square lattice, we show nonadiabatic beam dynamics that are highly sensitive to the direction of the index gradient and the choice of the Dirac cones. In particular, a symmetry-preserving potential leads to nearly perfect LZT and coherent BO between the inequivalent valleys, whereas a symmetry-breaking potential generates asymmetric scattering, imperfect LZT, and valley-sensitive generation of vortices mediated by a pseudospin imbalance. This clearly indicates that, near the Dirac points, the transverse gradient does not always act as a simple scalar force, as commonly assumed, and the LZT probability is strongly affected by the sublattice symmetry as analyzed from an effective Landau-Zener Hamiltonian. Our results illustrate the anisotropic response of an otherwise isotropic Dirac platform to real-space potentials acting as strong driving fields, which may be useful for manipulation of pseudospin and valley degrees of freedom in graphenelike systems.
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Affiliation(s)
- Yong Sun
- Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA
- MOE Key Laboratory of Advanced Micro-Structured Materials, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
| | - Daniel Leykam
- Center for Theoretical Physics of Complex Systems, Institute for Basic Science, Daejeon 34126, Republic of Korea
| | - Stephen Nenni
- Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA
| | - Daohong Song
- MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China
| | - Hong Chen
- MOE Key Laboratory of Advanced Micro-Structured Materials, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
| | - Y D Chong
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371, Singapore
| | - Zhigang Chen
- Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA
- MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China
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7
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Bloch Oscillations in the Chains of Artificial Atoms Dressed with Photons. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8060937] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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8
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Zhang Y, Wang R, Zhong H, Zhang J, Belić MR, Zhang Y. Optical Bloch oscillation and Zener tunneling in the fractional Schrödinger equation. Sci Rep 2017; 7:17872. [PMID: 29259234 PMCID: PMC5736706 DOI: 10.1038/s41598-017-17995-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 12/04/2017] [Indexed: 12/03/2022] Open
Abstract
We demonstrate optical Bloch oscillation (OBO) and optical Zener tunneling (OZT) in the fractional Schrödinger equation (FSE) with periodic and linear potentials, numerically and theoretically. We investigate in parallel the regular Schrödinger equation and the FSE, by adjusting the Lévy index, and expound the differences between the two. We find that the spreading of the OBO decreases in the fractional case, due to the diminishing band width. Increasing the transverse force, due to the linear potential, leads to the appearance of OZT, but this process is suppressed in the FSE. Our results indicate that the adjustment of the Lévy index can effectively control the emergence of OBO and OZT, which can inspire new ideas in the design of optical switches and interconnects.
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Affiliation(s)
- Yiqi Zhang
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, Xi'an Jiaotong University, Xi'an, 710049, China.
- Department of Applied Physics, School of Science, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Rong Wang
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Hua Zhong
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Jingwen Zhang
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Milivoj R Belić
- Science Program, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar
| | - Yanpeng Zhang
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, Xi'an Jiaotong University, Xi'an, 710049, China
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9
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The New Concept of Nano-Device Spectroscopy Based on Rabi–Bloch Oscillations for THz-Frequency Range. APPLIED SCIENCES-BASEL 2017. [DOI: 10.3390/app7070721] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
We considered one-dimensional quantum chains of two-level Fermi particles coupled via the tunneling driven both by ac and dc fields in the regimes of strong and ultrastrong coupling. The frequency of ac field is matched with the frequency of the quantum transition. Based on the fundamental principles of electrodynamics and quantum theory, we developed a general model of quantum dynamics for such interactions. We showed that the joint action of ac and dc fields leads to the strong mutual influence of Rabi- and Bloch oscillations, one to another. We focused on the regime of ultrastrong coupling, for which Bloch- and Rabi-frequencies are significant values of the frequency of interband transition. The Hamiltonian was solved numerically, with account of anti-resonant terms. It manifests by the appearance of a great number of narrow high-amplitude resonant lines in the spectra of tunneling current and dipole moment. We proposed the new concept of terahertz (THz) spectroscopy, which is promising for different applications in future nanoelectronics and nano-photonics.
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11
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Artoni M, La Rocca GC, Ferrari G. Quasi-periodic Wannier–Stark ladders from driven atomic Bloch oscillations. Proc Math Phys Eng Sci 2014. [DOI: 10.1098/rspa.2014.0421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Periodic Wannier–Stark ladder structures of the energy resonances associated with Bloch oscillations can be readily modified into quasi-periodic ones that exhibit peculiar self-similar effects. A compact theoretical description of the dynamics of driven Bloch oscillations is developed here within the quasi-momentum representation. We identify a rather viable scheme based on ultracold atomic wavepackets subject to gravity in a driven optical lattice potential where a self-similar scaling could be observed. Its feasibility in terms of realistic experimental parameters is also discussed.
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Affiliation(s)
- M. Artoni
- Department of Engineering and Information Technology, Brescia University, Brescia, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS) and Istituto Nazionale di Ottica (INO), Firenze, Italy
| | | | - G. Ferrari
- European Laboratory for Nonlinear Spectroscopy (LENS) and Istituto Nazionale di Ottica (INO), Firenze, Italy
- INO-CNR BEC Center and Dipartimento di Fisica, Trento University, 38123 Povo, Italy
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12
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Peng W, Zhou L, Long S, Wang J, Zhan M. Locking laser frequency of up to 40 GHz offset to a reference with a 10 GHz electro-optic modulator. OPTICS LETTERS 2014; 39:2998-3001. [PMID: 24978257 DOI: 10.1364/ol.39.002998] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We demonstrate a method to lock a laser frequency of up to 40 GHz offset to a reference using a 10 GHz waveguide-type electro-optic modulator (EOM). Offsetting is provided by the EOM sidebands, and first- to fourth-order sidebands are generated by changing the power of the EOM's driving radio frequency. By scanning the driving frequency across the 10 GHz bandwidth, the output laser frequency can be set at any point in an 80 GHz range (from -40 to 40 GHz) by locking a sideband to the reference. This method provides simple, stable, and low-cost generation of phase-coherent laser pairs separated by tens of GHz.
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13
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Windpassinger P, Sengstock K. Engineering novel optical lattices. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2013; 76:086401. [PMID: 23828639 DOI: 10.1088/0034-4885/76/8/086401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Optical lattices have developed into a widely used and highly recognized tool to study many-body quantum physics with special relevance for solid state type systems. One of the most prominent reasons for this success is the high degree of tunability in the experimental setups. While at the beginning quasi-static, cubic geometries were mainly explored, the focus of the field has now shifted toward new lattice topologies and the dynamical control of lattice structures. In this review we intend to give an overview of the progress recently achieved in this field on the experimental side. In addition, we discuss theoretical proposals exploiting specifically these novel lattice geometries.
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Affiliation(s)
- Patrick Windpassinger
- Institut für Laserphysik and Zentrum für Optische Quantentechnologien, Universität Hamburg, Hamburg, Germany.
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14
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Mandt S, Rapp A, Rosch A. Interacting fermionic atoms in optical lattices diffuse symmetrically upwards and downwards in a gravitational potential. PHYSICAL REVIEW LETTERS 2011; 106:250602. [PMID: 21770621 DOI: 10.1103/physrevlett.106.250602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 05/23/2011] [Indexed: 05/31/2023]
Abstract
We consider a cloud of fermionic atoms in an optical lattice described by a Hubbard model with an additional linear potential. While homogeneous interacting systems mainly show damped Bloch oscillations and heating, a finite cloud behaves differently: It expands symmetrically such that gains of potential energy at the top are compensated by losses at the bottom. Interactions stabilize the necessary heat currents by inducing gradients of the inverse temperature 1/T, with T<0 at the bottom of the cloud. An analytic solution of hydrodynamic equations shows that the width of the cloud increases with t^{1/3} for long times consistent with results from our Boltzmann simulations.
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Affiliation(s)
- Stephan Mandt
- Institute for Theoretical Physics, University of Cologne, 50937 Cologne, Germany
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15
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Haller E, Hart R, Mark MJ, Danzl JG, Reichsöllner L, Nägerl HC. Inducing transport in a dissipation-free lattice with super Bloch oscillations. PHYSICAL REVIEW LETTERS 2010; 104:200403. [PMID: 20867014 DOI: 10.1103/physrevlett.104.200403] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 03/11/2010] [Indexed: 05/22/2023]
Abstract
Particles in a perfect lattice potential perform Bloch oscillations when subject to a constant force, leading to localization and preventing conductivity. For a weakly interacting Bose-Einstein condensate of Cs atoms, we observe giant center-of-mass oscillations in position space with a displacement across hundreds of lattice sites when we add a periodic modulation to the force near the Bloch frequency. We study the dependence of these "super" Bloch oscillations on lattice depth, modulation amplitude, and modulation frequency and show that they provide a means to induce linear transport in a dissipation-free lattice.
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Affiliation(s)
- Elmar Haller
- Institut für Experimentalphysik and Zentrum für Quantenphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
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16
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Cadoret M, de Mirandes E, Cladé P, Guellati-Khélifa S, Schwob C, Nez F, Julien L, Biraben F. Combination of BLOCH oscillations with a Ramsey-Bordé interferometer: new determination of the fine structure constant. PHYSICAL REVIEW LETTERS 2008; 101:230801. [PMID: 19113536 DOI: 10.1103/physrevlett.101.230801] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Indexed: 05/27/2023]
Abstract
We report a new experimental scheme which combines atom interferometry with Bloch oscillations to provide a new measurement of the ratio h/mRb. By using Bloch oscillations, we impart to the atoms up to 1600 recoil momenta and thus we improve the accuracy on the recoil velocity measurement. The deduced value of h/mRb leads to a new determination of the fine structure constant alpha(-1) =137.03599945 (62) with a relative uncertainty of 4.6 x 10(-9). The comparison of this result with the value deduced from the measurement of the electron anomaly provides the most stringent test of QED.
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Affiliation(s)
- Malo Cadoret
- Laboratoire Kastler Brossel, Ecole Normale Supérieure, Université Pierre et Marie Curie, CNRS, 4 place Jussieu, 75252 Paris Cedex 05, France
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17
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Salerno M, Konotop VV, Bludov YV. Long-living BLOCH oscillations of matter waves in periodic potentials. PHYSICAL REVIEW LETTERS 2008; 101:030405. [PMID: 18764242 DOI: 10.1103/physrevlett.101.030405] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Indexed: 05/26/2023]
Abstract
The dynamics of matter waves in linear and nonlinear optical lattices subject to a spatially uniform linear force is studied both analytically and numerically. It is shown that by properly designing the spatial dependence of the scattering length it is possible to induce long-living Bloch oscillations of gap-soliton matter waves in optical lattices. This occurs when the effective nonlinearity and the effective mass of the soliton have opposite signs for all values of the crystal momentum in the Brillouin zone. The results apply to all systems modeled by the periodic nonlinear Schrödinger equation, including propagation of light in photonic and photorefractive crystals with tilted band structures.
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Affiliation(s)
- M Salerno
- Dipartimento di Fisica E. R. Caianiello, and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Universitá di Salerno, I-84081, Baronissi (SA), Italy
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18
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Fattori M, D'Errico C, Roati G, Zaccanti M, Jona-Lasinio M, Modugno M, Inguscio M, Modugno G. Atom interferometry with a weakly interacting Bose-Einstein condensate. PHYSICAL REVIEW LETTERS 2008; 100:080405. [PMID: 18352607 DOI: 10.1103/physrevlett.100.080405] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Indexed: 05/26/2023]
Abstract
We demonstrate the operation of an atom interferometer based on a weakly interacting Bose-Einstein condensate. We strongly reduce the interaction induced decoherence that usually limits interferometers based on trapped condensates by tuning the s-wave scattering length almost to zero via a magnetic Feshbach resonance. We employ a 39K condensate trapped in an optical lattice, where Bloch oscillations are forced by gravity. The fine-tuning of the scattering length down to 0.1 a_(0) and the micrometric sizes of the atomic sample make our system a very promising candidate for measuring forces with high spatial resolution. Our technique can be in principle extended to other measurement schemes opening new possibilities in the field of trapped atom interferometry.
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Affiliation(s)
- M Fattori
- Dipartimento di Fisica, Università di Firenze, and INFM-CNR Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
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19
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Gustavsson M, Haller E, Mark MJ, Danzl JG, Rojas-Kopeinig G, Nägerl HC. Control of interaction-induced dephasing of Bloch oscillations. PHYSICAL REVIEW LETTERS 2008; 100:080404. [PMID: 18352606 DOI: 10.1103/physrevlett.100.080404] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Indexed: 05/26/2023]
Abstract
We report on the control of interaction-induced dephasing of Bloch oscillations for an atomic Bose-Einstein condensate in an optical lattice. We quantify the dephasing in terms of the width of the quasimomentum distribution and measure its dependence on time for different interaction strengths which we control by means of a Feshbach resonance. For minimal interaction, the dephasing time is increased from a few to more than 20 thousand Bloch oscillation periods, allowing us to realize a BEC-based atom interferometer in the noninteracting limit.
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Affiliation(s)
- M Gustavsson
- Institut für Experimentalphysik und Forschungszentrum für Quantenphysik, Universität Innsbruck, 6020 Innsbruck, Austria
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20
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Cladé P, de Mirandes E, Cadoret M, Guellati-Khélifa S, Schwob C, Nez F, Julien L, Biraben F. Determination of the fine structure constant based on BLOCH oscillations of ultracold atoms in a vertical optical lattice. PHYSICAL REVIEW LETTERS 2006; 96:033001. [PMID: 16486694 DOI: 10.1103/physrevlett.96.033001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Indexed: 05/06/2023]
Abstract
We report an accurate measurement of the recoil velocity of 87Rb atoms based on Bloch oscillations in a vertical accelerated optical lattice. We transfer about 900 recoil momenta with an efficiency of 99.97% per recoil. A set of 72 measurements of the recoil velocity, each one with a relative uncertainty of about 33 ppb in 20 min integration time, leads to a determination of the fine structure constant with a statistical relative uncertainty of 4.4 ppb. The detailed analysis of the different systematic errors yields to a relative uncertainty of 6.7 ppb. The deduced value of alpha-1 is 137.035 998 78(91).
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Affiliation(s)
- Pierre Cladé
- Laboratoire Kastler Brossel, Ecole Normale Supérieure, CNRS, UPMC, 4 place Jussieu, 75252 Paris Cedex 05, France
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21
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Dunningham J, Burnett K, Phillips WD. Bose-Einstein condensates and precision measurements. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2005; 363:2165-75. [PMID: 16147504 DOI: 10.1098/rsta.2005.1636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
An ongoing challenge in physics is to make increasingly accurate measurements of physical quantities. Bose-Einstein condensates in atomic gases are ideal candidates for use in precision measurement schemes since they are extremely cold and have laser-like coherence properties. In this paper, we review these two attributes and discuss how they could be exploited to improve the resolution in a range of different measurements.
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Affiliation(s)
- Jacob Dunningham
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK
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Carusotto I, Pitaevskii L, Stringari S, Modugno G, Inguscio M. Sensitive measurement of forces at the micron scale using Bloch oscillations of ultracold atoms. PHYSICAL REVIEW LETTERS 2005; 95:093202. [PMID: 16197214 DOI: 10.1103/physrevlett.95.093202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Indexed: 05/04/2023]
Abstract
We show that Bloch oscillations of ultracold fermionic atoms in the periodic potential of an optical lattice can be used for a sensitive measurement of forces at the micrometer length scale, e.g., in the vicinity of a dielectric surface. In particular, the proposed approach allows us to perform a local and direct measurement of the Casimir-Polder force which is, for realistic experimental parameters, as large as 10(-4) gravity.
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Affiliation(s)
- I Carusotto
- Istituto Nazionale per Fisica per la Materia BEC-CRS and Dipartimento di Fisica, Universitá di Trento, I-38050 Povo, Italy
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Campbell GK, Leanhardt AE, Mun J, Boyd M, Streed EW, Ketterle W, Pritchard DE. Photon recoil momentum in dispersive media. PHYSICAL REVIEW LETTERS 2005; 94:170403. [PMID: 15904272 DOI: 10.1103/physrevlett.94.170403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Indexed: 05/02/2023]
Abstract
A systematic shift of the photon recoil momentum due to the index of refraction of a dilute gas of atoms has been observed. The recoil frequency was determined with a two-pulse light grating interferometer using near-resonant laser light. The results show that the recoil momentum of atoms caused by the absorption of a photon is n variant Planck's k, where n is the index of refraction of the gas and k is the vacuum wave vector of the photon. This systematic effect must be accounted for in high-precision atom interferometry with light gratings.
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Affiliation(s)
- Gretchen K Campbell
- MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Ma ZY, d'Arcy MB, Gardiner SA. Gravity-sensitive quantum dynamics in cold atoms. PHYSICAL REVIEW LETTERS 2004; 93:164101. [PMID: 15524992 DOI: 10.1103/physrevlett.93.164101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2003] [Revised: 06/24/2004] [Indexed: 05/24/2023]
Abstract
We subject a falling cloud of cold cesium atoms to periodic kicks from a sinusoidal potential created by a vertical standing wave of laser light. By controllably accelerating the potential, we show quantum accelerator mode dynamics to be highly sensitive to the effective gravitational acceleration when close to specific, resonant values. This quantum sensitivity to a control parameter is reminiscent of that associated with classical chaos and promises techniques for precision measurement.
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Affiliation(s)
- Z-Y Ma
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
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