Article
Materials Science, Multidisciplinary
Janik Schoenmeier-Kromer, Lode Pollet
Summary: We investigate the phase diagram of a one-dimensional Bose-Fermi-Hubbard model with scalar bosons at unit filling and S=1/2 fermions at half filling using quantum Monte Carlo simulations. The fermion-fermion interaction is set to zero. The main focus of our study is to understand the induced interactions between the fermions by the bosons, both for weak and strong interspecies coupling. We find that these induced interactions can result in competing instabilities favoring phase separation, superconducting phases, and density wave structures, often occurring on length scales of more than 100 sites. Additionally, we observe marginal bosonic superfluids with faster decay of the density matrix compared to pure bosonic systems with on-site interactions.
Article
Mechanics
L. Krutyansky, V. Preobrazhensky, A. Brysev, P. Pernod, R. Klopotov
Summary: Parametric instability of a standing gravity-capillary wave is observed when a liquid surface is irradiated by a plane ultrasound beam modulated by amplitude. The threshold value of ultrasound intensity for exciting the parametric oscillations of the surface is determined and the frequency response of the process is measured.
Article
Physics, Multidisciplinary
Jannes Merckx, Jacques Tempere
Summary: This study investigates the behavior of solitons in ultracold quantum gases at interfaces between different interaction regimes. Regardless of whether the original soliton passes through the interface, there will be a shockwave with reflected secondary solitons created, serving as important experimental probes for testing microscopic theories of pairing in ultracold Fermi gases.
FRONTIERS IN PHYSICS
(2022)
Article
Multidisciplinary Sciences
Inaki Garcia-Elcano, Jaime Merino, Jorge Bravo-Abad, Alejandro Gonzalez-Tudela
Summary: Fermi arcs are surface states connecting topologically distinct Weyl points, which showcase the topological aspects of Weyl physics. We investigate the photonic counterpart of these states and demonstrate unique phenomena. We show how to image the Fermi arcs through the spontaneous decay of emitters coupled to the system's border. We also demonstrate the potential of Fermi arc surface states as a robust quantum link, enabling perfect quantum state transfer and the formation of highly entangled states.
Article
Optics
Khalid Hossain, Subhadeep Gupta, Michael McNeil Forbes
Summary: In this experiment, a ring geometry is used to directly detect the entrainment effect in a mixture of bosonic and fermionic superfluids. The choice of ring geometry eliminates variations in the mean-field interaction strength, enhancing the detection of entrainment-induced phase gradient.
Article
Physics, Multidisciplinary
Jin-Ge Chen, Yue-Ran Shi, Ren Zhang, Kui-Yi Gao, Wei Zhang
Summary: We investigated the possibility of stabilizing an FFLO state in a two-component Fermi gas trapped in a moving two-dimensional optical lattice, finding that a finite pairing momentum can be induced perpendicular to the moving direction for nearly half filling, leading to a tilt of the total pairing momentum towards the nesting vector for an enhancement of the density of states.
Article
Physics, Multidisciplinary
Fang Li, Shujin Deng, Liang Zhang, Jiahui Xia, Licheng Yi, Haibin Wu
Summary: Patterns resulting from modulation instability have been extensively studied in optics and Bose-Einstein condensates, but not yet in ultracold Fermi gases. Experimental observation of space-time patterns in a superfluid Fermi gas excited by red-detuned laser light reveals different types of patterns induced by longitudinally spatially fluctuated laser beams. Patterns in strongly interacting Fermi gases accompanied by phonon excitations demonstrate a striking X-type dispersion relation, while patterns in noninteracting Fermi gases are stationary without phonon excitations and have a longer lifetime.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2021)
Article
Mechanics
Shimin Zhang, Alistair G. L. Borthwick, Zhiliang Lin
Summary: This paper investigates the steady-state pattern evolution of symmetric Faraday waves excited in a brimful cylindrical container when driving parameters much exceed critical thresholds. A modified free-surface synthetic Schlieren method is employed to obtain full three-dimensional spatial reconstructions of instantaneous surface patterns. The study reveals the nonlinear mechanisms behind pattern formation and the primary pathways of energy transfer.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Physics, Multidisciplinary
Seyed Mostafa Moniri, Heshmatollah Yavari, Elnaz Darsheshdar
Summary: This study investigates the low-temperature shear viscosity of a one-component p-wave superfluid Fermi gas in the strong-coupling limit, taking into account the p-wave Cooper channel in the self-energy. The viscous relaxation rates determined are temperature-dependent and differ from the s-wave superfluid Fermi gas, due to anisotropic pairing interaction in the p-wave superfluid. This research contributes to understanding how anisotropy affects transport properties of this unconventional superfluid Fermi gas in the low temperature limit.
Article
Physics, Multidisciplinary
A. Hammond, L. Lavoine, T. Bourdel
Summary: Researchers propose and demonstrate the existence of an effective attractive three-body interaction in coherently driven two-component Bose-Einstein condensates. This interaction originates from the spinor degree of freedom affected by a two-body mean-field shift of the driven transition frequency. The strength of this interaction can be controlled using the Rabi-coupling strength and does not result in additional losses. In the experiment, the three-body interactions are adjusted to play a predominant role in the equation of state of a cigar-shaped trapped condensate.
PHYSICAL REVIEW LETTERS
(2022)
Article
Mechanics
X. Shao, P. Wilson, J. R. Saylor, J. B. Bostwick
Summary: This study analyzed the dynamics of surface waves excited by mechanical vibration in a cylindrical container, finding that control of the meniscus geometry had a significant effect on the generation and mixing of edge waves and Faraday waves. Theoretical predictions using the Rayleigh-Ritz procedure were in excellent agreement with experimental results.
JOURNAL OF FLUID MECHANICS
(2021)
Review
Multidisciplinary Sciences
B. Dinesh, J. Livesay, I. B. Ignatius, R. Narayanan
Summary: This article reviews two types of resonance-derived interfacial instability, with a focus on the effect of side walls on interfacial mode discretization. The first type is mechanical Faraday instability, and the second is electrostatic Faraday instability. Both resonances are discussed for single-frequency forcing. In the case of mechanical resonance, inviscid theory can predict the expected modal forms when viscosity is considered, and experiments validate the theory. The article also examines electrostatic resonant instability, which leads to a specific mode resembling Rayleigh Taylor instability, and experiments show good agreement with theoretical predictions. An important distinction between the two resonances is the gradual rise in negative detuning instability observed in mechanical Faraday's case, compared to the sharp rise in the case of electrostatic resonance.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2023)
Article
Mechanics
Alessandro Bongarzone, Francesco Viola, Simone Camarri, Francois Gallaire
Summary: In this study, a weakly nonlinear analysis method was used to successfully predict the impact of viscosity and static contact angle on the instability onset of viscous subharmonic standing waves under different wetting conditions. The interaction between wetting conditions and parametric waves was systematically quantified and explained.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Physics, Multidisciplinary
Jian Feng, Wei-Wei Zhang, Liang-Wei Lin, Qi-Peng Cai, Yi-Cai Zhang, Sheng-Can Ma, Chao-Fei Liu
Summary: This paper investigates the topological superfluid phase diagram of a two-dimensional mass-imbalanced Fermi gas with Rashba spin-orbit coupling at zero temperature. The study finds a double-well structure in the thermodynamic potential due to the competition among mass imbalance, pairing interaction, and spin-orbit coupling, which affects the properties of the ground state. The phase diagrams are provided on the plane of spin-orbit coupling and chemical potential, as well as the plane of reduced mass ratio and two-body binding energy, offering a theoretical basis for better observation of topological superfluid state in experiments.
Article
Materials Science, Multidisciplinary
Zuo Wang, Li-Jun Lang, Liang He
Summary: We investigate the ground state and quantum dynamics of an interacting bosonic chain with nonreciprocal hopping. In systems with noninteger filling, the ground state supports Mott insulators due to the competition between nonreciprocal hopping and the on-site interaction. The conservation laws for non-Hermitian systems show a stark difference compared to their Hermitian counterpart. We establish a generic approach for constructing conserved quantities and illustrate it in the studied system. Mott insulators with noninteger filling and non-Hermitian conservation laws can be observed in ultracold atoms in optical lattices with engineered nonreciprocal hopping.