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Pinotti E, Longhi S. Accelerating Quantum Decay by Multiple Tunneling Barriers. ENTROPY (BASEL, SWITZERLAND) 2023; 25:1345. [PMID: 37761644 PMCID: PMC10527801 DOI: 10.3390/e25091345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/13/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023]
Abstract
A quantum particle constrained between two high potential barriers provides a paradigmatic example of a system sustaining quasi-bound (or resonance) states. When the system is prepared in one of such quasi-bound states, the wave function approximately maintains its shape but decays in time in a nearly exponential manner radiating into the surrounding space, the lifetime being of the order of the reciprocal of the width of the resonance peak in the transmission spectrum. Naively, one could think that adding more lateral barriers would preferentially slow down or prevent the quantum decay since tunneling is expected to become less probable and due to quantum backflow induced by multiple scattering processes. However, this is not always the case and in the early stage of the dynamics quantum decay can be accelerated (rather than decelerated) by additional lateral barriers, even when the barrier heights are arbitrarily large. The decay acceleration originates from resonant tunneling effects and is associated to large deviations from an exponential decay law. We discuss such a counterintuitive phenomenon by considering the hopping dynamics of a quantum particle on a tight-binding lattice with on-site potential barriers.
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Affiliation(s)
- Ermanno Pinotti
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, I-20133 Milano, Italy
| | - Stefano Longhi
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, I-20133 Milano, Italy
- IFISC (UIB-CSIC), Instituto de Fisica Interdisciplinar y Sistemas Complejos, E-07122 Palma de Mallorca, Spain
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2
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Seal D, Chaudhury P, Ghosh S. Coherent destruction of tunnelling in a symmetrical double well driven by a series of time dependent δ functions. JOURNAL OF PHYSICS A: MATHEMATICAL AND THEORETICAL 2022; 55:425307. [DOI: 10.1088/1751-8121/ac980c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
Abstract
Abstract
It is analytically and numerically shown that the coherent tunnelling between the individual wells of a symmetrical double well potential can be totally suppressed when it is driven by a periodic series of δ function in time, depending on the time period and strength of the δ function. We have applied time dependent perturbation theory to have an understanding over the process. In absence of any kind of perturbation, the average position of the particle makes a sinusoidal oscillation between two wells. With the application of a periodic δ function, the amplitude and the frequency of the oscillation both get modified. In this article we have explored how the frequency and strength of the applied perturbation controls the quantum dynamics of tunnelling and finally, how these parameters drive the system towards a complete stand still situation, which is described as coherent destruction of tunnelling.
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3
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Chakraborty B, Jha R, Kar S, Chattaraj PK. Controlling Tunneling Oscillation and Quantum Localization in an Asymmetric Double-Well Potential: A Bohmian Perspective. J Phys Chem A 2022; 126:4834-4847. [PMID: 35834735 DOI: 10.1021/acs.jpca.2c03049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The roles of spatial symmetry and strength of external time-dependent perturbation on the dynamics of a quantum particle, initially localized in one of the wells of an asymmetric double-well potential are studied using the recently developed techniques incorporating quantum theory of motion and time-dependent Fourier grid Hamiltonian methods. The model used here includes a mimic of the related experimental situations which is considered as a perturbation to the static double-well potential. Analysis of localized and delocalized phase space structures and corresponding time-profile of tunneling probability reveal the recipe toward controlling the tunneling oscillations by modulating the parameters of applied perturbation. A study on a stochastic pulsating potential also reveals the root to the quantum localization, even in moderate field strength.
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Affiliation(s)
- Bhrigu Chakraborty
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Ruchi Jha
- Advanced Technology Development Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Susmita Kar
- Department of Chemistry, Scottish Church College, Kolkata 700006, India
| | - Pratim Kumar Chattaraj
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
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4
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Longhi S. Equivalence principle and quantum mechanics: quantum simulation with entangled photons. OPTICS LETTERS 2018; 43:226-229. [PMID: 29328244 DOI: 10.1364/ol.43.000226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 12/04/2017] [Indexed: 06/07/2023]
Abstract
Einstein's equivalence principle (EP) states the complete physical equivalence of a gravitational field and corresponding inertial field in an accelerated reference frame. However, to what extent the EP remains valid in non-relativistic quantum mechanics is a controversial issue. To avoid violation of the EP, Bargmann's superselection rule forbids a coherent superposition of states with different masses. Here we suggest a quantum simulation of non-relativistic Schrödinger particle dynamics in non-inertial reference frames, which is based on the propagation of polarization-entangled photon pairs in curved and birefringent optical waveguides and Hong-Ou-Mandel quantum interference measurement. The photonic simulator can emulate superposition of mass states, which would lead to violation of the EP.
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Thuberg D, Muñoz E, Eggert S, Reyes SA. Perfect Spin Filter by Periodic Drive of a Ferromagnetic Quantum Barrier. PHYSICAL REVIEW LETTERS 2017; 119:267701. [PMID: 29328722 DOI: 10.1103/physrevlett.119.267701] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Indexed: 06/07/2023]
Abstract
We consider the problem of particle tunneling through a periodically driven ferromagnetic quantum barrier connected to two leads. The barrier is modeled by an impurity site representing a ferromagnetic layer or a quantum dot in a tight-binding Hamiltonian with a local magnetic field and an ac-driven potential, which is solved using the Floquet formalism. The repulsive interactions in the quantum barrier are also taken into account. Our results show that the time-periodic potential causes sharp resonances of perfect transmission and reflection, which can be tuned by the frequency, the driving strength, and the magnetic field. We demonstrate that a device based on this configuration could act as a highly tunable spin valve for spintronic applications.
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Affiliation(s)
- Daniel Thuberg
- Instituto de Física and Centro de Investigación en Nanotecnología y Materiales Avanzados, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile
| | - Enrique Muñoz
- Instituto de Física and Centro de Investigación en Nanotecnología y Materiales Avanzados, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile
| | - Sebastian Eggert
- Physics Department and Research Center OPTIMAS, University of Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - Sebastián A Reyes
- Instituto de Física and Centro de Investigación en Nanotecnología y Materiales Avanzados, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile
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Chitsazi M, Li H, Ellis FM, Kottos T. Experimental Realization of Floquet PT-Symmetric Systems. PHYSICAL REVIEW LETTERS 2017; 119:093901. [PMID: 28949577 DOI: 10.1103/physrevlett.119.093901] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Indexed: 06/07/2023]
Abstract
We provide an experimental framework where periodically driven PT-symmetric systems can be investigated. The setup, consisting of two ultra high frequency oscillators coupled by a time-dependent capacitance, demonstrates a cascade of PT-symmetric broken domains bounded by exceptional point degeneracies. These domains are analyzed and understood using an equivalent Floquet frequency lattice with local PT symmetry. Management of these PT-phase transition domains is achieved through the amplitude and frequency of the drive.
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Affiliation(s)
- Mahboobeh Chitsazi
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, USA
| | - Huanan Li
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, USA
| | - F M Ellis
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, USA
| | - Tsampikos Kottos
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, USA
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Mukherjee S, Thomson RR. Observation of robust flat-band localization in driven photonic rhombic lattices. OPTICS LETTERS 2017; 42:2243-2246. [PMID: 28614322 DOI: 10.1364/ol.42.002243] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 05/01/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate that a flat-band state in a quasi-one-dimensional rhombic lattice is robust in the presence of external drivings along the lattice axis. The lattice was formed by periodic arrays of evanescently coupled optical waveguides, and the external drivings were realized by modulating the paths of the waveguides. We excited a superposition of flat-band eigenmodes at the input and observed that this state does not diffract in the presence of static, as well as high-frequency sinusoidal drivings. This robust localization is due to destructive interference of the analogous wavefunction and is associated with the symmetry in the lattice geometry. We then excited the dispersive bands and observed Bloch oscillations and coherent destruction of tunneling.
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8
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Coherent control of quasi-degenerate stationary-like states via multiple resonances. Sci Rep 2017; 7:21. [PMID: 28154422 PMCID: PMC5428370 DOI: 10.1038/s41598-017-00041-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 12/20/2016] [Indexed: 11/18/2022] Open
Abstract
We use three bosons held in a depth-tilt combined-modulated double-well to study coherent control of quantum transitions between quasi-degenerate stationary-like states (QDSLSs) with the same quasienergy. Within the high-frequency approximation and for multiple-resonance conditions, we analytically obtain the different QDSLSs including the maximal bipartite entangled states, which enable us to manipulate the transitions between QDSLSs without the observable multiphoton absorption and to simulate a two-qubit system with the considered bosons. The analytical results are confirmed numerically and good agreement is shown. The quantum transitions between QDSLSs can be observed and controlled by adjusting the initial and the final atomic distributions in the currently proposed experimental setup, and possess potential applications in qubit control based on the bipartite entangled states and in engineering quantum dynamics for quantum information processing.
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Monaco R. Engineering double-well potentials with variable-width annular Josephson tunnel junctions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:445702. [PMID: 27604250 DOI: 10.1088/0953-8984/28/44/445702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Long Josephson tunnel junctions are non-linear transmission lines that allow propagation of current vortices (fluxons) and electromagnetic waves and are used in various applications within superconductive electronics. Recently, the Josephson vortex has been proposed as a new superconducting qubit. We describe a simple method to create a double-well potential for an individual fluxon trapped in a long elliptic annular Josephson tunnel junction characterized by an intrinsic non-uniform width. The distance between the potential wells and the height of the inter-well potential barrier are controlled by the strength of an in-plane magnetic field. The manipulation of the vortex states can be achieved by applying a proper current ramp across the junction. The read-out of the state is accomplished by measuring the vortex depinning current in a small magnetic field. An accurate one-dimensional sine-Gordon model for this strongly non-linear system is presented, from which we calculate the position-dependent fluxon rest-mass, its Hamiltonian density and the corresponding trajectories in the phase space. We examine the dependence of the potential properties on the annulus eccentricity and its electrical parameters and address the requirements for observing quantum-mechanical effects, as discrete energy levels and tunneling, in this two-state system.
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Affiliation(s)
- Roberto Monaco
- CNR-ISASI, Institute of Applied Sciences and Intelligent Systems 'E. Caianello', Comprensorio Olivetti, 80078 Pozzuoli, Italy
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10
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An analog of photon-assisted tunneling in a periodically modulated waveguide array. Sci Rep 2016; 6:35744. [PMID: 27767189 PMCID: PMC5073318 DOI: 10.1038/srep35744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 10/04/2016] [Indexed: 11/12/2022] Open
Abstract
We theoretically report an analog of photon-assisted tunneling (PAT) originated from dark Floquet state in a periodically driven lattice array without a static biased potential by studying a three-channel waveguide system in a non-high-frequency regime. This analog of PAT can be achieved by only periodically modulating the top waveguide and adjusting the distance between the bottom and its adjacent waveguide. It is numerically shown that the PAT resonances also exist in the five-channel waveguide system and probably exist in the waveguide arrays with other odd numbers of waveguides, but they will become weak as the number of waveguides increases. With origin different from traditional PAT, this type of PAT found in our work is closely linked to the existence of the zero-energy (dark) Floquet states. It is readily observable under currently accessible experimental conditions and may be useful for controlling light propagation in waveguide arrays.
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11
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Kar S, Bhattacharyya S. Classical oscillators in the control of quantum tunneling: Numerical experiments. Chem Phys 2016. [DOI: 10.1016/j.chemphys.2016.03.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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12
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Sala M, Gatti F, Guérin S. Coherent destruction of tunneling in a six-dimensional model of NHD2: A computational study using the multi-configuration time-dependent Hartree method. J Chem Phys 2014; 141:164326. [DOI: 10.1063/1.4900518] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Matthieu Sala
- Laboratoire Interdisciplinaire Carnot de Bourgogne UMR 6303 CNRS, Université de Bourgogne, BP 47870, F-21078 Dijon, France
| | - Fabien Gatti
- CTMM, Institut Charles Gerhardt (UMR 5253), CC1501, Université Montpellier II, F-34095 Montpellier, Cedex 05, France
| | - Stéphane Guérin
- Laboratoire Interdisciplinaire Carnot de Bourgogne UMR 6303 CNRS, Université de Bourgogne, BP 47870, F-21078 Dijon, France
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13
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Longhi S. Aharonov-Bohm photonic cages in waveguide and coupled resonator lattices by synthetic magnetic fields. OPTICS LETTERS 2014; 39:5892-5895. [PMID: 25361112 DOI: 10.1364/ol.39.005892] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We suggest a method for trapping photons in quasi-one-dimensional waveguide or coupled-resonator lattices, which is based on an optical analogue of the Aharonov-Bohm cages for charged particles. Light trapping results from a destructive interference of Aharonov-Bohm type induced by a synthetic magnetic field, which is realized by periodic modulation of the waveguide/resonator propagation constants/resonances.
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14
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Hai K, Luo Y, Lu G, Hai W. Phase-controlled localization and directed transport in an optical bipartite lattice. OPTICS EXPRESS 2014; 22:4277-4289. [PMID: 24663751 DOI: 10.1364/oe.22.004277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigate coherent control of a single atom interacting with an optical bipartite lattice via a combined high-frequency modulation. Our analytical results show that the quantum tunneling and dynamical localization can depend on phase difference between the modulation components, which leads to a different route for the coherent destruction of tunneling and a convenient phase-control method for stabilizing the system to implement the directed transport of atom. The similar directed transport and the phase-controlled quantum transition are revealed for the corresponding many-particle system. The results can be referable for experimentally manipulating quantum transport and transition of cold atoms in the tilted and shaken optical bipartite lattice or of analogical optical two-mode quantum beam splitter, and also can be extended to other optical and solid-state systems.
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15
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Kartashov YV, Vysloukh VA, Torner L. Enhancement and inhibition of light tunneling mediated by resonant mode conversion. OPTICS LETTERS 2014; 39:933-936. [PMID: 24562245 DOI: 10.1364/ol.39.000933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We show that the rate at which light tunnels between neighboring multimode waveguides can be drastically increased or reduced by the presence of small longitudinal periodic modulations of the waveguide properties that stimulate resonant conversion between the eigenmodes of each waveguide. Such a conversion, available only in multimode guiding structures, leads to periodic power transfer into higher-order modes, whose tails may considerably overlap with neighboring waveguides. As a result, the effective coupling constant for neighboring waveguides may change by several orders of magnitude upon small variations in the longitudinal modulation parameters.
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Maeshima N, Yamada K, Hino KI. Laser-controlled exciton Fano resonance in semiconductor superlattices. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:435801. [PMID: 24097286 DOI: 10.1088/0953-8984/25/43/435801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Quantum control of excitonic Floquet states in semiconductor superlattices driven by an intense monochromatic laser is examined from a theoretical point of view. High-resolution optical absorption spectra, calculated using multichannel scattering theory with the R-matrix propagation method, clarified that the excitonic Fano resonance structure is induced by the laser field. Each of the physical quantities related to this resonance-such as the spectral intensity, an asymmetry parameter (q-parameter), a resonance width, and so on-shows a characteristic extremum as a function of laser strength (F(ac)) in the vicinity of a critical value of F(ac) where dynamic localization is realized. It has also been shown that this F(ac)-dependence is caused by an ac-Zener coupling between two photon sidebands. Further, we have shown that these quantities are also controlled by changing the laser frequency (ω), as well as F(ac), and the underlying physics is explained on the basis of anticrossing behavior of the two photon sidebands.
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Affiliation(s)
- Nobuya Maeshima
- Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8573, Japan. Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
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Tofighi S, Bahrampour AR. All-optical controlled switching in centrally coupled circular array of nonlinear optical fibers. APPLIED OPTICS 2013; 52:6131-6137. [PMID: 24085069 DOI: 10.1364/ao.52.006131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 07/22/2013] [Indexed: 06/02/2023]
Abstract
We show that, in a nonlinear centrally coupled circular array of evanescently coupled fibers, the coupling dynamics of a weak signal beam can be efficiently influenced by a high-power control beam that induces nonlinear defects. When the intense control beam is launched into the central core and one core in the periphery, then localized solitons are formed and cause the fibers with induced defects (defected fibers) to decouple from the other array elements. In the presence of a high-intensity control beam, the propagation of weak signal is restricted to the defected optical fibers. The weak signal periodically couples between the induced defects. This oscillatory behavior depends on the sign of the (Kerr-type) nonlinearity and the initial phase difference between the control fields injected to the central and one of the peripheral fibers. This all-optical network has the advantage of routing and switching the weak signal field in a controlled way by adjusting the parameters of intense control field.
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Huang C, Shi X, Ye F, Kartashov YV, Chen X, Torner L. Tunneling inhibition for subwavelength light. OPTICS LETTERS 2013; 38:2846-2849. [PMID: 23903159 DOI: 10.1364/ol.38.002846] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We show that light tunneling inhibition may take place in suitable dynamically modulated waveguide arrays for light spots whose features are remarkably smaller than the wavelength of light. We found that tunneling between neighboring waveguides can be suppressed for specific frequencies of the out-of-phase refractive index modulation, affording undistorted propagation of the input subwavelength light spots over hundreds of Rayleigh lengths. Tunneling inhibition turns out to be effective only when the waveguide separation in the array is above a critical threshold. Inclusion of a weak focusing nonlinearity is shown to improve localization. We analyze the phenomenon in purely dielectric structures and also in arrays containing periodically spaced metallic layers.
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Affiliation(s)
- Changming Huang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Physics Department, Shanghai Jiao Tong University, Shanghai, China
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20
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Luo X, Huang J, Zhong H, Qin X, Xie Q, Kivshar YS, Lee C. Pseudo-parity-time symmetry in optical systems. PHYSICAL REVIEW LETTERS 2013; 110:243902. [PMID: 25165925 DOI: 10.1103/physrevlett.110.243902] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Indexed: 06/03/2023]
Abstract
We introduce a novel concept of the pseudo-parity-time (pseudo-PT) symmetry in periodically modulated optical systems with balanced gain and loss. We demonstrate that whether or not the original system is PT symmetric, we can manipulate the property of the PT symmetry by applying a periodic modulation in such a way that the effective system derived by the high-frequency Floquet method is PT symmetric. If the original system is non-PT symmetric, the PT symmetry in the effective system will lead to quasistationary propagation that can be associated with the pseudo-PT symmetry. Our results provide a promising approach for manipulating the PT symmetry of realistic systems.
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Affiliation(s)
- Xiaobing Luo
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275, China and Department of Physics, Jinggangshan University, Ji'an 343009, China
| | - Jiahao Huang
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
| | - Honghua Zhong
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
| | - Xizhou Qin
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
| | - Qiongtao Xie
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275, China and Department of Physics and Key Laboratory of Low-Dimensional Quantum Structure and Quantum Control of Ministry of Education, Hunan Normal University, Changsha 410081, China
| | - Yuri S Kivshar
- Nonlinear Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200, Australia
| | - Chaohong Lee
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275, China and Nonlinear Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200, Australia
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Kar S, Ghosh S, Bhattacharyya S. Bichromatic fluctuations in symmetric double well potentials: Localization and control of tunneling. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2012.04.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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22
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Kar S, Bhattacharyya S. Tunneling time in fluctuating symmetric double wells: Suppression and enhancement of tunneling by spatial symmetry-preserving perturbations. Chem Phys 2011. [DOI: 10.1016/j.chemphys.2010.10.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Kartashov YV, Vysloukh VA, Torner L. Bloch-wave packet control in truncated modulated optical lattices. OPTICS LETTERS 2010; 35:4220-4222. [PMID: 21165143 DOI: 10.1364/ol.35.004220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We study the reflection of Bloch wave packets at the interface of an optical lattice possessing a shallow longitudinal out-of-phase refractive index modulation in the adjacent waveguides. We show that the relation between the transmitted and reflected energy flows can be efficiently controlled by tuning the frequency and depth of the modulation. Thus, complete beam reflection may be achieved for a set of resonant modulation frequencies at which light tunneling between adjacent guides of modulated lattice is inhibited.
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Affiliation(s)
- Yaroslav V Kartashov
- ICFO-Institut de Ciencies Fotoniques and Universitat Politecnica de Catalunya, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain.
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24
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Instantaneous coherent destruction of tunneling and fast quantum state preparation for strongly pulsed spin qubits in diamond. Chem Phys 2010. [DOI: 10.1016/j.chemphys.2010.03.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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25
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Effect of a high-frequency magnetic field on the resonant behavior displayed by a spin-1/2 particle under the influence of a rotating magnetic field. Chem Phys 2010. [DOI: 10.1016/j.chemphys.2010.05.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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26
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Kartashov YV, Vysloukh VA. Light tunneling inhibition in longitudinally modulated Bragg-guiding arrays. OPTICS LETTERS 2010; 35:2097-2099. [PMID: 20548398 DOI: 10.1364/ol.35.002097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We consider a waveguide array in which defect channels with reduced refractive index are spaced periodically and the light guiding is achieved because of Bragg reflection. We show that tunneling between defects can be inhibited using out-of-phase longitudinal modulation of refractive index exclusively in defect channels. Tunneling inhibition is almost perfect for strongly localized modes with propagation constants close to the gap center.
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Affiliation(s)
- Yaroslav V Kartashov
- Institut de Ciencies Fotoniques, and Universitat Politecnica de Catalunya, Mediterranean Technology Park, 08860 Castelldefels, Barcelona, Spain.
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Szameit A, Garanovich IL, Heinrich M, Sukhorukov AA, Dreisow F, Pertsch T, Nolte S, Tünnermann A, Longhi S, Kivshar YS. Observation of two-dimensional dynamic localization of light. PHYSICAL REVIEW LETTERS 2010; 104:223903. [PMID: 20867171 DOI: 10.1103/physrevlett.104.223903] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 05/05/2010] [Indexed: 05/29/2023]
Abstract
We report on the first experimental observation of dynamic localization of light in two-dimensional photonic lattices. We demonstrate suppression of beam diffraction in hexagonal lattices created by weakly coupled waveguides with axis bending. We also reveal that this effect is strongly related to dynamic localization in zigzag waveguide arrays with next-nearest neighboring interactions.
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Affiliation(s)
- Alexander Szameit
- Solid State Institute and Physics Department, Technion, 32000 Haifa, Israel
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28
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Xie Q, Luo X, Wu B. All-optical switch with two periodically modulated nonlinear waveguides. OPTICS LETTERS 2010; 35:321-323. [PMID: 20125708 DOI: 10.1364/ol.35.000321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We propose a type of all-optical switch which consists of two periodically modulated nonlinear optical waveguides placed in parallel. Compared to the all-optical switch based on the traditional nonlinear directional coupler without periodic modulation, this all-optical switch has much lower switching threshold power and sharper switching width.
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Affiliation(s)
- Qiongtao Xie
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
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29
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30
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Wang J, Gong J. Generating a fractal butterfly Floquet spectrum in a class of driven SU(2) systems. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 81:026204. [PMID: 20365635 DOI: 10.1103/physreve.81.026204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Indexed: 05/29/2023]
Abstract
A scheme for generating a fractal butterfly Floquet spectrum, first proposed by Wang and Gong [Phys. Rev. A 77, 031405(R) (2008)], is extended to driven SU(2) systems such as a driven two-mode Bose-Einstein condensate. A class of driven systems without a link with the Harper-model context is shown to have an intriguing butterfly Floquet spectrum. The found butterfly spectrum shows remarkable deviations from the known Hofstadter's butterfly. In addition, the level crossings between Floquet states of the same parity and between Floquet states of different parities are studied and highlighted. The results are relevant to studies of fractal statistics, quantum chaos, and coherent destruction of tunneling, as well as the validity of mean-field descriptions of Bose-Einstein condensates.
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Affiliation(s)
- Jiao Wang
- Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005, China.
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31
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Kartashov YV, Vysloukh VA. Light tunneling inhibition in array of couplers with longitudinal refractive index modulation. OPTICS LETTERS 2010; 35:205-207. [PMID: 20081969 DOI: 10.1364/ol.35.000205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We consider light tunneling inhibition in a periodic array of optical couplers due to the specially designed longitudinal and transverse modulation of the refractive index. We show that local out-of-phase longitudinal modulation of refractive index in channels of directional couplers in combination with the global refractive index modulation between adjacent couplers allow simultaneous suppression of both local and global energy tunneling inside each coupler and between adjacent couplers. This enables the localization of light in single waveguide despite the remarkable difference of corresponding local and global energy tunneling rates.
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Affiliation(s)
- Yaroslav V Kartashov
- ICFO-Institut de Ciencies Fotoniques and Universitat Politecnica de Catalunya, Mediterranean Technology Park,08860 Castelldefels (Barcelona), Spain.
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32
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Kartashov YV, Vysloukh VA. Switching management in couplers with biharmonic longitudinal modulation of refractive index. OPTICS LETTERS 2009; 34:3544-3546. [PMID: 19927205 DOI: 10.1364/ol.34.003544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We address light propagation in couplers with longitudinal biharmonic modulation of refractive index in neighboring channels. While simplest single-frequency out-of-phase modulation allows suppression of coupling for a strictly defined set of resonant frequencies, the addition of modulation on multiple frequencies dramatically modifies the structure of resonances. Thus, additional modulation on a double frequency may suppress the primary resonance, while modulation on a triple frequency causes fusion of primary and secondary resonances.
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Affiliation(s)
- Yaroslav V Kartashov
- Institut de Ciencies Fotoniques, and Universitat Politecnica de Catalunya, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
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33
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Joushaghani A, Iyer R, Poon JKS, Aitchison JS, de Sterke CM, Wan J, Dignam MM. Quasi-BLOCH oscillations in curved coupled optical waveguides. PHYSICAL REVIEW LETTERS 2009; 103:143903. [PMID: 19905569 DOI: 10.1103/physrevlett.103.143903] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Indexed: 05/28/2023]
Abstract
We report the observation of quasi-Bloch oscillations, a recently proposed, new type of dynamic localization in the spatial evolution of light in a curved coupled optical waveguide array. By spatially resolving the optical intensity at various propagation distances, we show the delocalization and final relocalization of the beam in the waveguide array. Through comparisons with other structures, we show that this dynamic localization is robust beyond the nearest-neighbor tight-binding approximation and exhibits a wavelength dependence different from conventional dynamic localization.
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Affiliation(s)
- Arash Joushaghani
- Department of Electrical and Computer Engineering and Institute for Optical Science, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada.
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34
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Gelin MF, Egorova D, Domcke W. Manipulating electronic couplings and nonadiabatic nuclear dynamics with strong laser pulses. J Chem Phys 2009; 131:124505. [DOI: 10.1063/1.3236577] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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35
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Gong J, Morales-Molina L, Hänggi P. Many-body coherent destruction of tunneling. PHYSICAL REVIEW LETTERS 2009; 103:133002. [PMID: 19905509 DOI: 10.1103/physrevlett.103.133002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2009] [Indexed: 05/28/2023]
Abstract
A new route to coherent destruction of tunneling is established by considering a monochromatic fast modulation of the self-interaction strength of a many-boson system. The modulation can be tuned such that only an arbitrarily, a priori prescribed number of particles are allowed to tunnel. The associated tunneling dynamics is sensitive to the odd or even nature of the number of bosons.
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Affiliation(s)
- Jiangbin Gong
- Department of Physics and Center for Computational Science and Engineering, National University of Singapore, Singapore 117542, Singapore.
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36
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Barak A, Lamhot Y, Friedland L, Segev M. Autoresonant dynamics of optical guided waves. PHYSICAL REVIEW LETTERS 2009; 103:123901. [PMID: 19792438 DOI: 10.1103/physrevlett.103.123901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2009] [Indexed: 05/28/2023]
Abstract
We study, theoretically and experimentally, autoresonant dynamics of optical waves in a spatially chirped nonlinear directional coupler. We show that adiabatic passage through a linear resonance in a weakly coupled light-wave system yields a sharp threshold transition to nonlinear phase locking and amplification to predetermined amplitudes. This constitutes the first observation of autoresonance phenomena in optics.
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Affiliation(s)
- Assaf Barak
- Physics Department, Technion - Israel Institute of Technology, Haifa 32000, Israel
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37
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Szameit A, Kartashov YV, Heinrich M, Dreisow F, Keil R, Nolte S, Tünnermann A, Vysloukh VA, Lederer F, Torner L. Nonlinearity-induced broadening of resonances in dynamically modulated couplers. OPTICS LETTERS 2009; 34:2700-2702. [PMID: 19756076 DOI: 10.1364/ol.34.002700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report the observation of nonlinearity-induced broadening of resonances in dynamically modulated directional couplers. When the refractive index of the guiding channels in the coupler is harmonically modulated along the propagation direction and is out-of-phase in two channels, coupling can be completely inhibited at resonant modulation frequencies. We observe that nonlinearity broadens such resonances and that localization can be achieved even in detuned systems at power levels well below those required in unmodulated couplers.
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Affiliation(s)
- A Szameit
- Physics Department and Solid State Institute, Technion, 32000 Haifa, Israel.
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38
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Wang J, Gong J. Butterfly Floquet spectrum in driven SU(2) systems. PHYSICAL REVIEW LETTERS 2009; 102:244102. [PMID: 19659010 DOI: 10.1103/physrevlett.102.244102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Indexed: 05/28/2023]
Abstract
The Floquet spectrum of a class of driven SU(2) systems is shown to display a butterfly pattern with multifractal properties. The level crossing between Floquet states of the same parity or different parities is studied. The results are relevant to studies of fractal statistics, quantum chaos, coherent destruction of tunneling, and the validity of mean-field descriptions of Bose-Einstein condensates.
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Affiliation(s)
- Jiao Wang
- Temasek Laboratories, National University of Singapore, 117542, Singapore
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39
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Della Valle G, Savoini M, Ornigotti M, Laporta P, Foglietti V, Finazzi M, Duò L, Longhi S. Experimental observation of a photon bouncing ball. PHYSICAL REVIEW LETTERS 2009; 102:180402. [PMID: 19518846 DOI: 10.1103/physrevlett.102.180402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 03/30/2009] [Indexed: 05/27/2023]
Abstract
An optical analogue of a quantum particle bouncing on a hard surface under the influence of gravity (a quantum bouncer) is experimentally demonstrated using a circularly curved optical waveguide. Spatially resolved tunneling optical microscopy measurements of multiple beam reflections at the waveguide edge clearly show the appearance of wave packet collapses and revivals (either integer and fractional), corresponding to the full quantum regime of the quantum bouncer.
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Affiliation(s)
- G Della Valle
- Dipartimento di Fisica and Istituto di Fotonica e Nanotecnologie del CNR, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
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40
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Rego LG, Santos LF, Batista VS. Coherent Control of Quantum Dynamics with Sequences of Unitary Phase-Kick Pulses. Annu Rev Phys Chem 2009; 60:293-320. [DOI: 10.1146/annurev.physchem.040808.090409] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Coherent-optical-control schemes exploit the coherence of laser pulses to change the phases of interfering dynamical pathways and manipulate dynamical processes. These active control methods are closely related to dynamical decoupling techniques, popularized in the field of quantum information. Inspired by nuclear magnetic resonance spectroscopy, dynamical decoupling methods apply sequences of unitary operations to modify the interference phenomena responsible for the system dynamics thus also belonging to the general class of coherent-control techniques. This article reviews related developments in the fields of coherent optical control and dynamical decoupling, emphasizing the control of tunneling and decoherence in general model systems. Considering recent experimental breakthroughs in the demonstration of active control of a variety of systems, we anticipate that the reviewed coherent-control scenarios and dynamical-decoupling methods should raise significant experimental interest.
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Affiliation(s)
- Luis G.C. Rego
- Departamento de Física, Universidade Federal de Santa Catarina, Florianópolis, SC 88040-900 Brazil
| | - Lea F. Santos
- Department of Physics, Yeshiva University, New York, New York 10016
| | - Victor S. Batista
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107
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41
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Szameit A, Kartashov YV, Dreisow F, Heinrich M, Pertsch T, Nolte S, Tünnermann A, Vysloukh VA, Lederer F, Torner L. Inhibition of light tunneling in waveguide arrays. PHYSICAL REVIEW LETTERS 2009; 102:153901. [PMID: 19518631 DOI: 10.1103/physrevlett.102.153901] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Indexed: 05/27/2023]
Abstract
We report the observation of almost perfect light tunneling inhibition at the edge and inside laser-written waveguide arrays due to band collapse. When the refractive index of the guiding channels is harmonically modulated along the propagation direction and out-of-phase in adjacent guides, light is trapped in the excited waveguide over a long distance due to resonances. The phenomenon can be used for tuning the localization threshold power.
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Affiliation(s)
- A Szameit
- Institute of Applied Physics, Friedrich-Schiller-University Jena, 07743 Jena, Germany
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42
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Igarashi A, Yamada H. Numerical study on dynamical behavior in oscillatory driven quantum double-well systems. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 78:026213. [PMID: 18850927 DOI: 10.1103/physreve.78.026213] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Revised: 05/07/2008] [Indexed: 05/26/2023]
Abstract
We numerically investigate quantum dynamics in a one-dimensional double-well system emphasizing influence of a parametrically polychromatic perturbation on the dynamics. It is found that time dependence of transition probability for an initially localized wave packet between the wells shows two types of motion, coherent and incoherent motion, depending on the perturbation parameters. As the strength and/or the number of frequency components of the perturbation increase, coherent motion changes into incoherent one. The former is related to coherent tunneling of the wave packet due to coherence; the latter is related to a delocalized state caused by decoherence. In coherent motion, by virtue of coherence of the dynamics, the expectation value and the standard deviation of a dynamical variable such as the energy of the system show oscillatory time dependence around the initial values. On the contrary in incoherent motion, because of the decoherence, the time dependence fluctuates irregularly around a certain value after a rapid increase due to the resonance. We find that negativity of the Wigner function also show similar time dependence in each type of motion. We compare the classification of the quantum dynamics based on regularity of the time dependence with the one of corresponding classical dynamics based on the Lyapunov exponent. The classifications of the quantum and classical dynamics overlap well in the parameter space. Furthermore, we confirm decoherence of quantum dynamics in a kicked double-well system.
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Affiliation(s)
- Akira Igarashi
- Graduate School of Science and Technology, Niigata University, Ikarashi 2-Nochou 8050, Niigata 950-2181, Japan.
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43
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Kierig E, Schnorrberger U, Schietinger A, Tomkovic J, Oberthaler MK. Single-particle tunneling in strongly driven double-well potentials. PHYSICAL REVIEW LETTERS 2008; 100:190405. [PMID: 18518430 DOI: 10.1103/physrevlett.100.190405] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Indexed: 05/26/2023]
Abstract
We report on the first direct observation of coherent control of single-particle tunneling in a strongly driven double-well potential. In our setup atoms propagate in a periodic arrangement of double wells allowing the full control of the driving parameters such as frequency, amplitude, and even the space-time symmetry. Our experimental findings are in quantitative agreement with the predictions of the corresponding Floquet theory and are also compared to the predictions of a simple two mode model. Our experiments reveal directly the critical dependence of coherent destruction of tunneling on the generalized parity symmetry.
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Affiliation(s)
- E Kierig
- Kirchhoff-Institut für Physik, Universität Heidelberg, Heidelberg, Germany.
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44
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Lignier H, Sias C, Ciampini D, Singh Y, Zenesini A, Morsch O, Arimondo E. Dynamical control of matter-wave tunneling in periodic potentials. PHYSICAL REVIEW LETTERS 2007; 99:220403. [PMID: 18233266 DOI: 10.1103/physrevlett.99.220403] [Citation(s) in RCA: 131] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Indexed: 05/25/2023]
Abstract
We report on measurements of dynamical suppression of interwell tunneling of a Bose-Einstein condensate (BEC) in a strongly driven optical lattice. The strong driving is a sinusoidal shaking of the lattice corresponding to a time-varying linear potential, and the tunneling is measured by letting the BEC freely expand in the lattice. The measured tunneling rate is reduced and, for certain values of the shaking parameter, completely suppressed. Our results are in excellent agreement with theoretical predictions. Furthermore, we have verified that, in general, the strong shaking does not destroy the phase coherence of the BEC, opening up the possibility of realizing quantum phase transitions by using the shaking strength as the control parameter.
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Affiliation(s)
- H Lignier
- CNR-INFM, Dipartimento di Fisica "E. Fermi," Università di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
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