Article
Engineering, Mechanical
Hong Cao
Summary: In this study, we investigate the effect of Rosen-Zener tunneling on Bose-Einstein condensates in a triple-well potential using mean-field treatment. We first calculate the tunneling dynamics exactly in the linear case and observe that all atoms are trapped in the initially populated well. However, the introduction of nonlinear interaction significantly changes the tunneling dynamics, breaking the symmetry and leading to the emergence of self-trapping solutions within a fixed interval.
NONLINEAR DYNAMICS
(2023)
Article
Physics, Multidisciplinary
Sheng-Chang Li
Summary: This paper theoretically studies the tunneling time of a wave packet of Bose-condensed atoms passing through a square barrier. The authors find that the tunneling time shows different scaling laws in different energy regimes. For negative incident energy, the tunneling time decreases rapidly with decreasing incident velocity. In contrast, for positive incident energy smaller than the barrier height, the tunneling time increases slowly and then reaches a maximum, consistent with experimental results from Larmor clock experiments. The effect of barrier width on the maximum tunneling time, related to the uncertainty principle, is also discussed.
NEW JOURNAL OF PHYSICS
(2022)
Article
Optics
A. D. Garcia-Orozco, L. Madeira, M. A. Moreno-Armijos, A. R. Fritsch, P. E. S. Tavares, P. C. M. Castilho, A. Cidrim, G. Roati, V. S. Bagnato
Summary: We studied the emergence of universal scaling in the time-evolving momentum distribution of a harmonically trapped three-dimensional Bose-Einstein condensate, which was parametrically driven to a turbulent state. We found that the out-of-equilibrium dynamics post excitation can be described by a single function due to nearby nonthermal fixed points. The observed behavior connects the dynamics of a quantum turbulent state to several far-from-equilibrium phenomena.
Article
Multidisciplinary Sciences
Mengjie Wei, Wouter Verstraelen, Konstantinos Orfanakis, Arvydas Ruseckas, Timothy C. H. Liew, Ifor D. W. Samuel, Graham A. Turnbull, Hamid Ohadi
Summary: The authors demonstrate the on-the-fly reconfigurable optical trapping of organic polariton condensates, which are delocalized over a macroscopic distance from the excitation region. This study holds great potential for future research on polaritonic lattice physics.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
Ying Yao-Jun, Li Hai-Bin
Summary: This study investigates the dynamic behavior of Bose-Einstein condensates in an asymmetric double-well potential using two-mode theory and computer simulation. The change in energy difference between the potential wells leads to different dynamic behaviors of the condensate. The presence of nonlinear interaction affects the trapping and tunneling of the condensate, and the dynamic behavior is similar to that caused by energy difference in the case of an ideal condensate.
ACTA PHYSICA SINICA
(2023)
Article
Materials Science, Multidisciplinary
Jinguo Hu, Qingbo Wang, Xianghua Su, Yu Zhang, Linghua Wen
Summary: This study examines the properties of a spin-1 ferromagnetic Bose-Einstein condensate with SOC and DDI in a double-well potential. It reveals that the nonrotating system sustains various exotic ground-state phases, while the rotating system exhibits unique dynamic behaviors and topological structure transitions.
RESULTS IN PHYSICS
(2022)
Article
Physics, Multidisciplinary
Yi-Piao Wu, Guo-Qing Zhang, Cai-Xia Zhang, Jian Xu, Dan-Wei Zhang
Summary: We investigate the mean-field energy spectrum and dynamics in a Bose-Einstein condensate in a double-well potential with non-Hermiticity from the nonreciprocal hopping, and show that the interplay of nonreciprocity and nonlinearity leads to exotic properties. Under the two-mode and mean-field approximations, the nonreciprocal generalization of the nonlinear Schrodinger equation and Bloch equations of motion for this system are obtained. We analyze the PT phase diagram and the dynamical stability of fixed points. The reentrance of PT-symmetric phase and the reformation of stable fixed points with increasing the nonreciprocity parameter are found. Besides, we uncover a linear selftrapping effect induced by the nonreciprocity. In the nonlinear case, the self-trapping oscillation is enhanced by the nonreciprocity and then collapses in the PT-broken phase, and can finally be recovered in the reentrant PT-symmetric phase.
FRONTIERS OF PHYSICS
(2022)
Article
Mathematics, Interdisciplinary Applications
Hao Huang, Hongcheng Wang, Guihua Chen, Manna Chen, Chin Seong Lim, Kok-Cheong Wong
Summary: The existence and stability of quantum droplets in ultracold atoms in Bose-Einstein condensates with a radial period lattice under the Lee-Huang-Yang correction were studied. Both stable bell-shaped and ring-shaped zero-vorticity quantum droplets were found. It was observed that the existence curves of zero-vorticity quantum droplets could violate the necessary condition for stable solitons. Vortex quantum droplets remained stable with an embedded vorticity up to S = 10 in the presence of radial lattice potential and were trapped at the first and second circular trough of the lattice. The stability areas of vortex quantum droplets with different embedded vorticity were identified through long-time evolution.
CHAOS SOLITONS & FRACTALS
(2023)
Article
Physics, Multidisciplinary
Yaojun Ying, Lizhen Sun, Haibin Li
Summary: The dynamics of Bose-Einstein condensates (BECs) in a single-well potential are investigated using the mode-coupling method. It is found that symmetry plays a crucial role in the coupling between modes. A proper mode-coupling theory of BECs in a single-well potential should include at least four modes. The mode dynamics of non-ideal BECs with interaction exhibit rich behavior, with the combination of nonlinear coupling and initial condition leading to different regimes of mode dynamics.
Article
Physics, Multidisciplinary
Hongjuan Meng, Yushan Zhou, Xiaolin Li, Xueping Ren, Xiaohuan Wan, Zhikun Zhou, Wenyuan Wang, Yuren Shi
Summary: The study explores multipole gap solitons in honeycomb optical lattices, with bright solitary structures that can be in-phase or out-of-phase. Nonlinear dynamical stabilities of these solitons are investigated through direct simulations of the Gross-Pitaevskii equation, showing different stability or instability depending on the type of soliton and atomic interactions. Dipole gap solitons exhibit self-trapping or tunneling instabilities under atomic nonlinearity, supporting different regimes of tunneling or self-trapping for multipole solitons.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2021)
Article
Physics, Multidisciplinary
S. Baryshev, A. Zasedatelev, H. Sigurdsson, I Gnusov, J. D. Topfer, A. Askitopoulos, P. G. Lagoudakis
Summary: In this study, we conducted full polarization tomography on photon correlations in a spinor exciton-polariton condensate. Our measurements demonstrate the different forms of condensate pseudospin mean-field dynamics and their intrinsic relation to the condensate photon statistics.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
M. Iskin
Summary: We investigate a weakly interacting Bose-Einstein condensate in an optical lattice using a two-band Bose-Hubbard model. By considering both one-body and two-body terms, we analyze the contributions to the inverse effective-mass tensor of the superfluid carriers in the Bogoliubov spectrum. We find that, in addition to the usual inverse band-mass tensor, quantum-geometric contribution induced by two-body interactions also plays a significant role.
Article
Physics, Fluids & Plasmas
Zhihuan Luo, Yan Liu, Yongyao Li, Josep Batle, Boris A. Malomed
Summary: We propose a trapping-expulsion management (TEM) scheme to stabilize two-dimensional dynamical states against critical collapse driven by cubic self-attraction. The scheme can be implemented in optics or BEC through spatial or temporal periodic modulations. Numerical simulations and variational approximation are used to study the system. The stability boundaries are found as functions of the self-attraction strength and the parameters of the periodic modulation. Below the usual collapse threshold, stability is limited by the onset of parametric resonance. Above the collapse threshold, a new threshold is found through numerical simulations, with a relative increase of about 1.5% compared to the known threshold.
Article
Multidisciplinary Sciences
Silvana Palacios Alvarez, Pau Gomez, Simon Coop, Roberto Zamora-Zamora, Chiara Mazzinghi, Morgan W. Mitchell
Summary: We present a magnetic sensor with extremely high energy resolution, applied in the detection of Rb-87 single-domain spinor Bose-Einstein condensates. By utilizing nondestructive Faraday rotation probing, we have achieved a low-frequency magnetic sensitivity of 72(8) fT, and measured the volume, spin coherence time, and readout noise of the condensate experimentally.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Mathematics, Interdisciplinary Applications
Mikhail N. Smolyakov
Summary: In this paper, quantization of a weakly nonideal Bose gas at zero temperature is performed along the lines of the well-known Bogolyubov approach. By introducing nonoscillation modes and calculating nonlinear corrections, the analysis successfully recovers canonical commutation relations and solves the issue of nonconserved particle number at least in the case of free quasi-particles.
CHAOS SOLITONS & FRACTALS
(2021)
Editorial Material
Physics, Multidisciplinary
Tim Keller, Thomas Fogarty, Thomas Busch
Summary: The study demonstrates that a Tonks-Girardeau gas in a Bose-Einstein condensate can transition to a crystal-like Mott state without an externally imposed lattice potential. The phase transition depends on the interspecies interaction and temperature of the TG gas and can be measured through accessible observables in cold atom experiments. An effective model was also developed to accurately describe the system in the pinned insulator state and derive the critical temperature of the transition.
PHYSICAL REVIEW LETTERS
(2022)
Editorial Material
Physics, Multidisciplinary
Carlo Manzo, Gorka Munoz-Gil, Giovanni Volpe, Miguel Angel Garcia-March, Maciej Lewenstein, Ralf Metzler
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2023)
Article
Physics, Multidisciplinary
Nicolas Firbas, Oscar Garibo-i-Orts, Miguel Angel Garcia-March, J. Alberto Conejero
Summary: The results of the AnDi Challenge demonstrate the superior performance of machine learning methods, particularly recurrent neural networks (RNNs), in characterizing anomalous diffusion. A new architecture called ConvTransformer, combining convolutional and transformer networks, is proposed to extract features from diffusive trajectories. This approach achieves improved performance in determining the underlying diffusive regime, especially in short trajectories, which is crucial for experimental researchers.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2023)
Article
Physics, Condensed Matter
Sergi De Maria-Garcia, Albert Ferrando, J. Alberto Conejero, Pedro Fernandez De Cordoba, Miguel Angel Garcia-March
Summary: We propose a method for studying the dynamics of a quasi-two dimensional Bose-Einstein condensate with vortices at arbitrary locations. The method provides an analytical solution for the condensate's dynamics in a homogeneous medium and in a parabolic trap, assuming ideal non-interacting conditions. It also allows for predicting the merging time of vortices in the condensate by obtaining algebraic equations for the trajectories of phase singularities. Additionally, we adapt the method from photonics to Bose-Einstein condensates and extend it to trapped systems for the first time, and present numerical simulations considering nonlinear cases.
Article
Physics, Multidisciplinary
Jesus Mateos, Charles E. Creffield, Fernando Sols
Summary: We theoretically investigate the superfluidity of a one-dimensional boson system with periodically modulated hopping energy. The system exhibits novel superfluid features such as a cat-like ground state and interference between the ground-state wave function components. The dynamics of this system is driven by correlations and described by exotic Hamiltonian and current operators. Calculation of the dynamic form factor reveals the presence of an acoustic mode that guarantees superfluidity in the thermodynamic limit.
NEW JOURNAL OF PHYSICS
(2023)
Article
Optics
Jose Carlos Pelayo, Karol Gietka, Thomas Busch
Summary: In distributed quantum sensing, correlations between multiple modes of a photonic system are used to improve the precision of measuring an unknown parameter. This study investigates the metrological potential of a multimode, tilted Bose-Hubbard system and demonstrates that it can achieve parameter estimation at the Heisenberg limit. By optimizing the initial state, the limit can be reached without requiring correlations between different modes. Furthermore, strategies are proposed to obtain quadratic dependence on the number of modes in a more realistic experimental setup.
Article
Physics, Multidisciplinary
Mohamed Boubakour, Thomas Fogarty, Thomas Busch
Summary: We study a minimal quantum Otto heat engine with an interacting few-body system in a harmonic trap, where the interaction strength is considered as an additional tunable parameter during the work strokes. By calculating the figures of merit of the engine as a function of temperature, we clearly show in which parameter regimes the interactions assist in engine performance. We also compare the interaction-enhanced cycle with the case where the system remains scale-invariant, studying the finite-time dynamics and the subsequent tradeoff between efficiency and power.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Optics
Fam Le Kien, Sile Nic Chormaic, Thomas Busch
Summary: This study investigates the directional dependence of the coupling between a nanofiber-guided light field and a two-level atom with an electric quadrupole transition. It is found that the absolute value of the quadrupole Rabi frequency depends on the propagation direction of the light field in certain cases. The directional dependence of the coupling leads to directional dependence of spontaneous emission into guided modes. The study also reveals that the directional dependence of the atom-field coupling in the case of quadrupole transitions is not solely due to spin-orbit coupling of light, but also involves contributions from the gradient of the spatial phase factor of the field.
Article
Physics, Nuclear
Tomasz Sowinski, Miguel A. Garcia-March
Summary: In this work, the authors discuss the limitations of the eigenvalue continuation approach when applied to strongly correlated many-body systems. By using a simple system and model, they demonstrate that the eigenvector continuation is unable to surpass the accuracy of the sampling states. They propose the need for support from other complementary methods to overcome this inaccuracy.
Article
Optics
Fam Le Kien, Sile Nic Chormaic, Thomas Busch
Summary: The optical force between two coupled parallel nanofibers was studied using the array mode theory. It was found that the forces of even array modes are attractive, while the forces of odd array modes are repulsive. The optical forces depend on the array mode type, fiber radius, light wavelength, and fiber separation distance.
Article
Optics
Fam Le Kien, Sile Nic Chormaic, Thomas Busch
Summary: In this study, we investigate the transfer of angular momentum from guided photons to a two-level atom through electric quadrupole transition near an optical nanofiber. We demonstrate that the axial orbital torque exerted by the driving guided field on the atom is determined by the selection rules for the quadrupole transition and the conservation law of angular momentum with photon angular momentum given by Minkowski formulation. We calculate the torques for the quadrupole transitions between specific sublevels of different hyperfine-structure levels in a Rb-87 atom.
Article
Physics, Multidisciplinary
Christopher Campbell, Thomas Fogarty, Thomas Busch
Summary: We study the dynamics of an ultracold quantum many-body system when quenching between two super-symmetric Hamiltonians. We show that the dynamics can be conveniently described using knowledge about the initial state only. In the case of a fermionic gas initially trapped in an infinite box potential, we observe many-body revivals when quenching to higher order supersymmetric partner potentials, with some revivals being robust at finite temperatures.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Optics
Hao Lyu, Yongping Zhang, Thomas Busch
Summary: We propose a method to detect phonon and roton excitations in a two-dimensional Bose-Einstein condensate with Raman-induced spin-orbit coupling by perturbing the atomic cloud with a weak barrier. The two excitation modes can be observed by moving the barrier along different directions, and phonon excitations are identified by the appearance of solitary waves, while roton excitations lead to distinctive spatial density modulations. We demonstrate that this method can also be used to determine the anisotropic critical velocities of superfluid.
Article
Physics, Multidisciplinary
Lewis Ruks, Thomas Busch
Summary: This paper investigates wave propagation in generic Hermitian local periodic baths and examines the effects of anisotropy and quasibreaking of periodicity on resonant emission into the band of the bath. The exponential decay length of oscillating evanescent waves locally around caustics generally depends as a power law on the angle made between rho and the caustic in hyperbolic media. Furthermore, applying an artificial gauge field on the lattice allows for exploration of hyperbolic dispersion beyond previous regimes.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Optics
Fam Le Kien, D. F. Kornovan, Sile Nic Chormaic, Thomas Busch
Summary: This study investigates the Casimir-Polder potential of a multilevel alkali-metal atom near an optical nanofiber. The potential of low-lying excited states can be positive and repulsive in certain regions of atom-to-surface distances. The study also calculates the nanofiber-induced shifts of the transition frequencies of the atomic rubidium D-2 and D-1 lines.
