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Alihosseini F, Zali AR, Pakizeh T, Zandi H. Plasmonic internal-photoemission-based Si photodetector design suitable for optical communication. APPLIED OPTICS 2022; 61:6939-6946. [PMID: 36255776 DOI: 10.1364/ao.462171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/23/2022] [Indexed: 06/16/2023]
Abstract
We propose a high-performance plasmonic photodetector based on the internal photoemission (IPE) process for the C-band communication wavelength. This photodetector takes advantage of an embedded nanohole array in Schottky metal. Owing to localized surface plasmon resonance, the absorption of the active metal layer increases, which results in the generation of more hot carriers and subsequently compensates for the low efficiency of IPE-based photodetectors. Simulations show that for the proposed photodetector with 2-nm-thick Au, Cu, and Ag Schottky contacts, the absorptance dramatically enhances to 95.1%, 93.2%, and 98.2%, respectively, at the wavelength of 1.55 µm. For the detector based on Au, the highest external quantum efficiency of 25.3% and responsivity of 0.32 A/W are achieved at a reverse bias voltage of 1 V. Furthermore, the 3 dB bandwidth can exceed 369 GHz owing to the low capacitance of the structure and the fast transit time of carriers from the thin p-Si layer. Finally, by studying the current-voltage characteristics of the photodetector, it is shown that under the reverse bias voltage of 1 V, the dark current is 665 nA at room temperature, and by reducing the temperature to 200 K, it improves three orders of magnitude and decreases to 810 pA.
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2
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Two-Dimensional Solitons in Bose–Einstein Condensates with Spin–Orbit Coupling and Rydberg–Rydberg Interaction. PHOTONICS 2022. [DOI: 10.3390/photonics9050283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Applying an imaginary time evolution method (AITEM) to the system of Gross–Pitaevskii equations, we find two-dimensional stable solitons in binary atomic Bose–Einstein condensates with spin–orbit coupling (SOC) and the Rydberg–Rydberg interaction (RRI). The stability of 2D solitons by utilizing their norm and energy is discussed in detail. Depending on the SOC and Rydberg–Rydberg interaction, we find stable zero-vorticity and vortical solitons. Furthermore, we show that the solitons can be effectively tuned by the local and nonlocal nonlinearities of this system.
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Mann RB, Husin I, Patel H, Faizal M, Sulaksono A, Suroso A. Testing short distance anisotropy in space. Sci Rep 2021; 11:7474. [PMID: 33811224 PMCID: PMC8018969 DOI: 10.1038/s41598-021-86355-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 03/15/2021] [Indexed: 11/08/2022] Open
Abstract
The isotropy of space is not a logical requirement but rather is an empirical question; indeed there is suggestive evidence that universe might be anisotropic. A plausible source of these anisotropies could be quantum gravity corrections. If these corrections happen to be between the electroweak scale and the Planck scale, then these anisotropies can have measurable consequences at short distances and their effects can be measured using ultra sensitive condensed matter systems. We investigate how such anisotropic quantum gravity corrections modify low energy physics through an anisotropic deformation of the Heisenberg algebra. We discuss how such anisotropies might be observed using a scanning tunnelling microscope.
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Affiliation(s)
- Robert B Mann
- Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
- Perimeter Institute, 31 Caroline St. N., Waterloo, ON, N2L 2Y5, Canada
| | - Idrus Husin
- Departemen Fisika, FMIPA, Universitas Indonesia, Depok, 1624, Indonesia
- IoT and Physics Lab, Sampoerna University, Jakarta, 12780, Indonesia
| | - Hrishikesh Patel
- Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, V6T 1Z1, Canada.
| | - Mir Faizal
- Department of Physics and Astronomy, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada
- Irving K. Barber School of Arts and Sciences, University of British Columbia, Okanagan Campus, Kelowna, V1V1V7, Canada
- Canadian Quantum Research Center, 204-3002, 32 Ave, Vernon, BC, V1T 2L7, Canada
| | - Anto Sulaksono
- Departemen Fisika, FMIPA, Universitas Indonesia, Depok, 1624, Indonesia
| | - Agus Suroso
- Theoretical Physics Lab, THEPI Division, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung, 40132, Indonesia
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Entropy generation and dissipative heat transfer analysis of mixed convective hydromagnetic flow of a Casson nanofluid with thermal radiation and Hall current. Sci Rep 2021; 11:3926. [PMID: 33594105 PMCID: PMC7887280 DOI: 10.1038/s41598-021-83124-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 12/30/2020] [Indexed: 01/31/2023] Open
Abstract
The present article provides a detailed analysis of entropy generation on the unsteady three-dimensional incompressible and electrically conducting magnetohydrodynamic flow of a Casson nanofluid under the influence of mixed convection, radiation, viscous dissipation, Brownian motion, Ohmic heating, thermophoresis and heat generation. At first, similarity transformation is used to transform the governing nonlinear coupled partial differential equations into nonlinear coupled ordinary differential equations, and then the resulting highly nonlinear coupled ordinary differential equations are numerically solved by the utilization of spectral quasi-linearization method. Moreover, the effects of pertinent flow parameters on velocity distribution, temperature distribution, concentration distribution, entropy generation and Bejan number are depicted prominently through various graphs and tables. It can be analyzed from the graphs that the Casson parameter acts as an assisting parameter towards the temperature distribution in the absence of viscous and Joule dissipations, while it has an adverse effect on temperature under the impacts of viscous and Joule dissipations. On the contrary, entropy generation increases significantly for larger Brinkman number, diffusive variable and concentration ratio parameter, whereas the reverse effects of these parameters on Bejan number are examined. Apart from this, the numerical values of some physical quantities such as skin friction coefficients in x and z directions, local Nusselt number and Sherwood number for the variation of the values of pertinent parameters are displayed in tabular forms. A quadratic multiple regression analysis for these physical quantities has also been carried out to improve the present model's effectiveness in various industrial and engineering areas. Furthermore, an appropriate agreement is obtained on comparing the present results with previously published results.
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Mo XQ, Zhou M, Wang Y, Guo SJ. Robust MFC anti-windup scheme for LTI systems with norm-bounded uncertainty. Sci Rep 2021; 11:1970. [PMID: 33479256 PMCID: PMC7820593 DOI: 10.1038/s41598-021-81036-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 12/30/2020] [Indexed: 11/09/2022] Open
Abstract
On the basic of the fact that all signals in the practical system are always bounded, this paper proposes a 4-degree-of-freedom (DoF) anti-windup scheme for saturated systems with parametric uncertainty. A fairly straightforward tuning rule is introduced to the robust stability analysis for the proposed anti-windup structure under the framework of IQC (Integral Quadratic Constraint). And the sufficient stability conditions are derived to check the reasonable definiteness of the related transfer function. Moreover, the control design for disturbance response and set-point tracking response are two separate part in this proposed scheme. Numerical example demonstrates the effectiveness and the considerable performance improvement of the anti-windup compensator that is designed by the proposed technique.
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Affiliation(s)
- Xiao-Qin Mo
- Institute of Science and Technology, University of Sanya, Sanya City, 572000, Hainan Province, China.
| | - Mi Zhou
- Institute of Science and Technology, University of Sanya, Sanya City, 572000, Hainan Province, China
| | - Yuan Wang
- Institute of Science and Technology, University of Sanya, Sanya City, 572000, Hainan Province, China
| | - Shang-Jia Guo
- Haikou Power Supply Bureau, Hainan Power Grid Company, Haikou City, 570100, Hainan Province, China
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6
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Principle and Applications of the Coupling of Surface Plasmons and Excitons. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10051774] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Surface plasmons have been attracting increasing attention and have been studied extensively in recent decades because of their half-light and half-material polarized properties. On the one hand, the tightly confined surface plasmonic mode may reduce the size of integrated optical devices beyond the diffraction limit; on the other hand, it provides an approach toward enhancement of the interactions between light and matter. In recent experiments, researchers have realized promising applications for surface plasmons in quantum information processing, ultra-low-power lasers, and micro-nano processing devices by using plasmonic structures, which have demonstrated their superiority over traditional optics structures. In this paper, we introduce the theoretical principle of surface plasmons and review the research work related to the interactions between plasmons and excitons. Some perspectives with regard to the future development of plasmonic coupling are also outlined.
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Li Y, Chen C, Burton J, Park K, Heflin JR, Tao C. Self-assembled PCBM bilayers on graphene and HOPG examined by AFM and STM. NANOTECHNOLOGY 2018; 29:185703. [PMID: 29451137 DOI: 10.1088/1361-6528/aab00a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this work we report fabrication and characterization of phenyl-C61-butyric acid methyl ester (PCBM) bilayer structures on graphene and highly oriented pyrolytic graphite (HOPG). Through careful control of the PCBM solution concentration (from 0.1 to 2 mg ml-1) and the deposition conditions, we demonstrate that PCBM molecules self-assemble into bilayer structures on graphene and HOPG substrates. Interestingly, the PCBM bilayers are formed with two distinct heights on HOPG, but only one unique representative height on graphene. At elevated annealing temperatures, edge diffusion allows neighboring vacancies to merge into a more ordered structure. This is, to the best of our knowledge, the first experimental realization of PCBM bilayer structures on graphene. This work could provide valuable insight into fabrication of new hybrid, ordered structures for applications to organic solar cells.
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Affiliation(s)
- Yanlong Li
- Department of Physics, Virginia Tech, Blacksburg, VA 24061, United States of America
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8
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Hu AY, Wang HY. Investigation of possible phase transition of the frustrated spin-1/2 J 1-J 2-J 3 model on the square lattice. Sci Rep 2017; 7:10477. [PMID: 28874752 PMCID: PMC5585350 DOI: 10.1038/s41598-017-10986-8] [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: 06/06/2017] [Accepted: 08/17/2017] [Indexed: 11/13/2022] Open
Abstract
The frustrated spin-1/2 J1-J2-J3 antiferromagnet with exchange anisotropy on the two-dimensional square lattice is investigated. The exchange anisotropy is presented by η with 0 ≤ η < 1. The effects of the J1, J2, J3 and anisotropy on the possible phase transition of the Néel state and collinear state are studied comprehensively. Our results indicate that for J3 > 0 there are upper limits \documentclass[12pt]{minimal}
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\begin{document}$${J}_{3}^{c}$$\end{document}J3c and 0 ≤ η ≤ ηc, the Néel and collinear states have the same order-disorder transition point at J2 = J1/2. Nevertheless, when the J3 and η values beyond the upper limits, it is a paramagnetic phase at J2 = J1/2. For J3 < 0, in the case of 0 ≤ η < 1, the two states always have the same critical temperature as long as J2 = J1/2. Therefore, for J2 = J1/2, under such parameters, a first-order phase transition between the two states for these two cases below the critical temperatures may occur. When J2 ≠ J1/2, the Néel and collinear states may also exist, while they have different critical temperatures. When J2 > J1/2, a first-order phase transition between the two states may also occur. However, for J2 < J1/2, the Néel state is always more stable than the collinear state.
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Affiliation(s)
- Ai-Yuan Hu
- College of Physics and Electronic Engineering, Chongqing Normal University, Chongqing, 401331, China
| | - Huai-Yu Wang
- Department of Physics, Tsinghua University, Beijing, 100084, China.
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9
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The polarization and the fundamental sensitivity of 39K ( 133Cs)- 85Rb- 4He hybrid optical pumping spin exchange relaxation free atomic magnetometers. Sci Rep 2017; 7:6776. [PMID: 28755005 PMCID: PMC5533804 DOI: 10.1038/s41598-017-06434-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 06/12/2017] [Indexed: 11/08/2022] Open
Abstract
The hybrid optical pumping spin exchange relaxation free (SERF) atomic magnetometers can realize ultrahigh sensitivity measurement of magnetic field and inertia. We have studied the 85Rb polarization of two types of hybrid optical pumping SERF magnetometers based on 39K-85Rb-4He and 133Cs-85Rb-4He respectively. Then we found that 85Rb polarization varies with the number density of buffer gas 4He and quench gas N2, pumping rate of pump beam and cell temperature respectively, which will provide an experimental guide for the design of the magnetometer. We obtain a general formula on the fundamental sensitivity of the hybrid optical pumping SERF magnetometer due to shot-noise. The formula describes that the fundamental sensitivity of the magnetometer varies with the number density of buffer gas and quench gas, the pumping rate of pump beam, external magnetic field, cell effective radius, measurement volume, cell temperature and measurement time. We obtain a highest fundamental sensitivity of 1.5073 aT/Hz 1/2 (1 aT = 10-18 T) with 39K-85Rb-4He magnetometer between above two types of magnetometers when 85Rb polarization is 0.1116. We estimate the fundamental sensitivity limit of the hybrid optical pumping SERF magnetometer to be superior to 1.8359 × 10-2 aT/Hz 1/2, which is higher than the shot-noise-limited sensitivity of 1 aT/Hz 1/2 of K SERF atomic magnetometer.
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10
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Ji TT, Bu N, Chen FJ, Tao YC, Wang J. Coexistence of perfect spin filtering for entangled electron pairs and high magnetic storage efficiency in one setup. Sci Rep 2016; 6:24417. [PMID: 27074893 PMCID: PMC4830971 DOI: 10.1038/srep24417] [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: 01/06/2016] [Accepted: 03/29/2016] [Indexed: 11/30/2022] Open
Abstract
For Entangled electron pairs superconducting spintronics, there exist two drawbacks in existing proposals of generating entangled electron pairs. One is that the two kinds of different spin entangled electron pairs mix with each other. And the other is a low efficiency of entanglement production. Herein, we report the spin entanglement state of the ferromagnetic insulator (FI)/s-wave superconductor/FI structure on a narrow quantum spin Hall insulator strip. It is shown that not only the high production of entangled electron pairs in wider energy range, but also the perfect spin filtering of entangled electron pairs in the context of no highly spin-polarized electrons, can be obtained. Moreover, the currents for the left and right leads in the antiferromagnetic alignment both can be zero, indicating 100% tunnelling magnetoresistance with highly magnetic storage efficiency. Therefore, the spin filtering for entangled electron pairs and magnetic storage with high efficiencies coexist in one setup. The results may be experimentally demonstrated by measuring the tunnelling conductance and the noise power.
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Affiliation(s)
- T T Ji
- Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023, China
| | - N Bu
- Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023, China
| | - F J Chen
- Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023, China
| | - Y C Tao
- Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023, China
| | - J Wang
- Department of Physics, Southeast University, Nanjing 210096, China
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11
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Controlled Electromagnetically Induced Transparency and Fano Resonances in Hybrid BEC-Optomechanics. Sci Rep 2016; 6:22651. [PMID: 26955789 PMCID: PMC4783664 DOI: 10.1038/srep22651] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 02/17/2016] [Indexed: 11/09/2022] Open
Abstract
Cavity-optomechanics, a tool to manipulate mechanical effects of light to couple optical field with other physical objects, is the subject of increasing investigations, especially with regards to electromagnetically induced transparency (EIT). EIT, a result of Fano interference among different atomic transition levels, has acquired a significant importance in many areas of physics, such as atomic physics and quantum optics. However, controllability of such multi-dimensional systems has remained a crucial issue. In this report, we investigate the controllability of EIT and Fano resonances in hybrid optomechanical system composed of cigar-shaped Bose-Einstein condensate (BEC), trapped inside high-finesse Fabry-Pérot cavity with one vibrational mirror, driven by a single mode optical field and a transverse pump field. The transverse field is used to control the phenomenon of EIT. It is detected that the strength of transverse field is not only efficiently amplifying or attenuating out-going optical mode but also providing an opportunity to enhance the strength of Fano-interactions which leads to the amplification of EIT-window. To observe these phenomena in laboratory, we suggest a certain set of experimental parameters. The results provide a route for tunable manipulation of optical phenomena, like EIT, which could be a significant step in quantum engineering.
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12
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Andrianov ES, Chtchelkatchev NM, Pukhov AA. Noisy metamolecule: strong narrowing of fluorescence line. OPTICS LETTERS 2015; 40:3536-3539. [PMID: 26258351 DOI: 10.1364/ol.40.003536] [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 consider a metamolecule consisting of a bosonic mode correlated with a two-level system (TLS): it can be, for example, a plasmonic mode interacting with a quantum dot. We focus on the parameter range where all the correlations are strong and of the same order. The interaction between the bosonic mode is correlated with the TLS, external coherent drive, and dissipation. Quantum Monte Carlo simulations show that the fluorescence of this system at dissipation is larger than the driving amplitude and shows a strong (by the order of magnitude) narrowing of its spectral line. This effect may be related to kind of a quantum stochastic resonance. We show that the fluorescence corresponds to the finite domain over the coherent drive with sharp, low threshold, and that the Wigner function splits.
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13
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Photon Devil's staircase: photon long-range repulsive interaction in lattices of coupled resonators with Rydberg atoms. Sci Rep 2015; 5:11510. [PMID: 26108705 PMCID: PMC4479987 DOI: 10.1038/srep11510] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 05/28/2015] [Indexed: 11/09/2022] Open
Abstract
The realization of strong coherent interactions between individual photons is a long-standing goal in science and engineering. In this report, based on recent experimental setups, we derive a strong photon long-range repulsive interaction, by controlling the van der Waals repulsive force between Cesium Rydberg atoms located inside different cavities in extended Jaynes-Cummings-Hubbard lattices. We also find novel quantum phases induced by this photon long-range repulsive interaction. For example, without photon hopping, a photon Devil’s staircase, induced by the breaking of long-range translation symmetry, can emerge. If photon hopping occurs, we predict a photon-floating solid phase, due to the motion of particle- and hole-like defects. More importantly, for a large chemical potential in the resonant case, the photon hopping can be frozen even if the hopping term exists. We call this new phase the photon-frozen solid phase. In experiments, these predicted phases could be detected by measuring the number of polaritons via resonance fluorescence.
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14
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Yasir KA, Liu WM. Tunable bistability in hybrid Bose-Einstein condensate optomechanics. Sci Rep 2015; 5:10612. [PMID: 26035206 PMCID: PMC4451843 DOI: 10.1038/srep10612] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 04/21/2015] [Indexed: 11/09/2022] Open
Abstract
Cavity-optomechanics, a rapidly developing area of research, has made a remarkable progress. A stunning manifestation of optomechanical phenomena is in exploiting the mechanical effects of light to couple the optical degree of freedom with mechanical degree of freedom. In this report, we investigate the controlled bistable dynamics of such hybrid optomechanical system composed of cigar-shaped Bose-Einstein condensate (BEC) trapped inside high-finesse optical cavity with one moving-end mirror and is driven by a single mode optical field. The numerical results provide evidence for controlled optical bistability in optomechanics using transverse optical field which directly interacts with atoms causing the coupling of transverse field with momentum side modes, exited by intra-cavity field. This technique of transverse field coupling is also used to control bistable dynamics of both moving-end mirror and BEC. The report provides an understanding of temporal dynamics of moving-end mirror and BEC with respect to transverse field. Moreover, dependence of effective potential of the system on transverse field has also been discussed. To observe this phenomena in laboratory, we have suggested a certain set of experimental parameters. These findings provide a platform to investigate the tunable behavior of novel phenomenon like electromagnetically induced transparency and entanglement in hybrid systems.
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Affiliation(s)
- Kashif Ammar Yasir
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Wu-Ming Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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15
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Wu Q, Long XX, Zheng RL. High-level Stark Effect and Spectrum of Spherical Nanometer System. CHINESE J CHEM PHYS 2010. [DOI: 10.1088/1674-0068/23/05/608-614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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16
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Schmidt S, Blatter G. Strong coupling theory for the Jaynes-Cummings-Hubbard model. PHYSICAL REVIEW LETTERS 2009; 103:086403. [PMID: 19792743 DOI: 10.1103/physrevlett.103.086403] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Indexed: 05/28/2023]
Abstract
We present an analytic strong-coupling approach to the phase diagram and elementary excitations of the Jaynes-Cummings-Hubbard model describing a superfluid-insulator transition of polaritons in an array of coupled QED cavities. In the Mott phase, we find four modes corresponding to particle or hole excitations with lower and upper polaritons, respectively. Simple formulas are derived for the dispersion and spectral weights within a strong-coupling random-phase approximation (RPA). The phase boundary is calculated beyond RPA by including the leading correction due to quantum fluctuations.
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Affiliation(s)
- S Schmidt
- Institute for Theoretical Physics, ETH Zurich, 8093 Zurich, Switzerland
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17
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Ji AC, Sun Q, Xie XC, Liu WM. Josephson effect for photons in two weakly linked microcavities. PHYSICAL REVIEW LETTERS 2009; 102:023602. [PMID: 19257273 DOI: 10.1103/physrevlett.102.023602] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Indexed: 05/27/2023]
Abstract
We describe an optical system that allows for direct observation of the photonic Josephson effects in two weakly linked microcavities containing ultracold two-level atoms. We show that, by moving the ultracold atoms within one cavity, we could simulate an analogous superconducting circuit and realize both the alternating- and direct-current (ac and dc) photonic Josephson effects. This provides a strategy for constructing novel interference devices of coherent photons and enables new investigations of the effect of many-body physics in strongly coupled atom-cavity systems.
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Affiliation(s)
- An-Chun Ji
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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18
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Investigation of changes in properties of water under the action of a magnetic field. ACTA ACUST UNITED AC 2008. [DOI: 10.1007/s11433-008-0182-7] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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19
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Wang DL, Yan XH, Liu WM. Localized gap-soliton trains of Bose-Einstein condensates in an optical lattice. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 78:026606. [PMID: 18850961 DOI: 10.1103/physreve.78.026606] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Revised: 06/10/2008] [Indexed: 05/26/2023]
Abstract
We develop a systematic analytical approach to study the linear and nonlinear solitary excitations of quasi-one-dimensional Bose-Einstein condensates trapped in an optical lattice. For the linear case, the Bloch wave in the nth energy band is a linear superposition of Mathieu's functions ce_{n-1} and se_{n} ; and the Bloch wave in the nth band gap is a linear superposition of ce_{n} and se_{n} . For the nonlinear case, only solitons inside the band gaps are likely to be generated and there are two types of solitons-fundamental solitons (which is a localized and stable state) and subfundamental solitons (which is a localized but unstable state). In addition, we find that the pinning position and the amplitude of the fundamental soliton in the lattice can be controlled by adjusting both the lattice depth and spacing. Our numerical results on fundamental solitons are in quantitative agreement with those of the experimental observation [B. Eiermann, Phys. Rev. Lett. 92, 230401 (2004)]. Furthermore, we predict that a localized gap-soliton train consisting of several fundamental solitons can be realized by increasing the length of the condensate in currently experimental conditions.
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Affiliation(s)
- D L Wang
- College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
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