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A. I. Yakimenko

Publications and source records attributed to A. I. Yakimenko.

At least 19 recordsLinked to original sources

Controlled acoustic-driven vortex transport in coupled superfluid rings

Atomtronic quantum sensors based on trapped superfluids offer a promising platform for high-precision inertial measurements where the dynamics of quantized vortices can serve as sensitive probes of external forces. We analytically investigate persistent current oscillations between two density-coupled Bose-Einstein condensate rings and show that the vortex dynamics is governed by low-energy acoustic excitations circulating through the condensate bulk. The oscillation frequency and damping rate are quantitatively predicted by a simplified hydrodynamic model, in agreement with Bogoliubov-de Gennes analysis and Gross-Pitaevskii simulations. We identify the critical dissipation separating persistent oscillations from overdamped vortex localization. Furthermore, we demonstrate that periodic modulation of the inter-ring barrier at resonant frequencies enables controlled vortex transfer even when the condensates are well separated in density. These results clarify the role of collective hydrodynamic modes in circulation transfer and establish a framework for employing vortex dynamics in atomtronic quantum technologies.

cond-mat.quant-gas↗

Velocity dispersion profiles of dwarf spheroidal galaxies with self-interacting ultralight dark matter

Dark-matter-dominated dwarf galaxies provide an excellent laboratory for testing dark matter models at small scale and, in particular, the ultralight dark matter (ULDM) class of models. Within the framework of self-interacting bosonic dark matter, we use the observed velocity-dispersion profiles of seven dwarf spheroidal galaxies to constrain the parameters of ULDM. In our modeling, we account for the impact of the baryonic component on the velocity dispersion and ULDM halo structure. We find that the repulsive self-interaction of ULDM, which fits the observations, is almost negligible, consistent with non-interacting ULDM with a boson mass of approximately $1.6 \times 10^{-22}\,\mathrm{eV}$. In contrast, for attractively interacting ULDM, the best fit corresponds to a smaller boson mass of about $1.3 \times 10^{-22}\,\mathrm{eV}$, with self-interaction playing a significant role in shaping the dark-matter halo and thereby influencing the interpretation of observations.

astro-ph.GA↗

Dynamical friction in ultralight dark matter: Plummer sphere perspective

In models of dark matter composed of feebly interacting ultralight bosons in the state of Bose-Einstein condensate, the dynamical friction force acting on circularly moving globular clusters modelled as Plummer spheres is determined. Analytic expressions for both radial and tangential components of the dynamical friction force are given. We reveal that the dynamical friction force for the Plummer sphere deviates from that for a point probe of the same mass for a significantly large ratio of the Plummer sphere radius to its orbital radius, as well as for large values of the Mach number.

astro-ph.GA↗

Acceleration-induced transport of quantum vortices in joined atomtronic circuits

Persistent currents--inviscid quantized flow around an atomic circuit--are a crucial building block of atomtronic devices. We investigate how acceleration influences the transfer of persistent currents between two density-connected, ring-shaped atomic Bose-Einstein condensates, joined by a tunable weak link that controls system topology. We find that the acceleration of this system modifies both the density and phase dynamics between the rings, leading to a bias in the periodic vortex oscillations studied in T. Bland et al., Phys. Rev. Research 4, 043171 (2022). Accounting for dissipation suppressing such vortex oscillations, the acceleration facilitates a unilateral vortex transfer to the leading ring. We analyze how this transfer depends on the weak-link amplitude, the initial persistent current configuration, and the acceleration strength and direction. Characterization of the sensitivity to these parameters paves the way for a new platform for acceleration measurements, for which we outline a proof-of-concept ultracold double-ring accelerometer.

cond-mat.quant-gas↗

Vortex Lines in Ultralight Bosonic Dark Matter around Rotating Supermassive Black Holes

Theoretical analysis of the interaction between superfluid dark matter and rotating supermassive black holes offers a promising framework for probing quantum effects in ultralight dark matter and its role in galactic structure. We study how black hole rotation influences the state of ultralight bosonic dark matter, focusing on the stability and dynamics of vortex lines. The gravitational effects of both dark matter and the black hole on the physical properties of these vortex lines, including their precession around the black hole, are analyzed.

hep-ph↗

Dynamical friction in rotating ultralight dark matter galactic cores

Dynamical friction and stellar orbital motion in spiral galaxies with dark matter composed of ultralight bosons in the state of rotating Bose-Einstein condensate (BEC) are studied. It is found that the dynamical friction force is significantly affected by the topological charge of the vortex structure of the BEC core with the strongest effect at distances near the galactic center. It is also shown that the ultralight dark matter self-interaction plays an important role in studying the dynamical friction.

astro-ph.GA↗

Dynamical galactic effects induced by stable vortex structure in bosonic dark matter

The nature of dark matter (DM) remains one of the unsolved mysteries of modern physics. An intriguing possibility is to assume that DM consists of ultralight bosonic particles in the Bose-Einstein condensate (BEC) state. We study stationary DM structures by using the system of the Gross-Pitaevskii and Poisson equations, including the effective temperature effect with parameters chosen to describe the Milky Way galaxy. We have investigated DM structure with BEC core and isothermal envelope. We compare the spherically symmetric and vortex core states, which allows us to analyze the impact of the core vorticity on the halo density, velocity distribution, and, therefore, its gravitational field. Gravitational field calculation is done in the gravitoelectromagnetism approach to include the impact of the core rotation, which induces a gravimagnetic field. As result, the halo with a vortex core is characterized by smaller orbital velocity in the galactic disk region in comparison with the non-rotating halo. It is found that the core vorticity produces gravimagnetic perturbation of celestial body dynamics, which can modify the circular trajectories.

astro-ph.GA↗

Persistent current oscillations in a double-ring quantum gas

Vorticity in closed quantum fluid circuits is known to arise in the form of persistent currents. In this work, we develop a method to engineer transport of the quantized vorticity between density-coupled ring-shaped atomic Bose-Einstein condensates in experimentally accessible regimes. Introducing a tunable weak link between the rings, we observe and characterize the controllable periodic transfer of the current and investigate the role of temperature on suppressing these oscillations via a range of complementary state-of-the-art numerical methods. Our setup paves the way for precision measurements of local acceleration and rotation.

cond-mat.quant-gas↗

Stable vortex structures in colliding self-gravitating Bose-Einstein condensates

A key feature of ultra-light dark matter composed by bosons is the formation of superfluid Bose-Einstein condensate (BEC) structures on galactic scales. We study collisions of BEC solitonic and vortex structures in the framework of the Gross-Pitaevskii-Poisson model. It is found that the superfluid nature of bosonic dark matter leads to the formation of quantized vortex lines and vortex rings in interference patterns formed during collisions. Calculating the gravitational wave luminosity, we demonstrated that quantum interference patterns affect notably the gravitational wave radiation. We reveal that superfluid self-gravitating BECs can form stable localized vortex structures which remain robust even after a head-on collision.

nlin.PS↗

Josephson oscillations of edge solitons in a photonic-topological coupler

We introduce a scheme of a photonic coupler built of two parallel topological-insulator slab waveguides with the intrinsic Kerr nonlinearity, separated by a gap. Josephson oscillations (JO) of a single edge soliton created in one slab, and of a pair of solitons created in two slabs, are considered. The single soliton jumping between the slabs is subject to quick radiative decay. On the other hand, the JO of the copropagating soliton pair may be essentially more robust, as one soliton can absorb dispersive waves emitted by the other. The most robust JO regime is featured by the pair of solitons with phase shift $π$ between them.

nlin.PS↗

s- and p-superfluidity of Fermi atoms in Bose-Fermi mixtures

The p-wave superfluid is characterized by nontrivial topological characteristics essential for fault-tolerant quantum state manipulation. However, the practical realization of the p-wave state remains a challenging problem. We study the s- and p-wave superfluidity in mixtures of fermionic and spinor bosonic gases and derive a general set of the gap equations for these superfluid states. Numerically solving the gap equations for the s-wave state, we quantify the physical conditions for the realization of the pure p-wave state in a well-controlled environment of atomic physics in the absence of an admixture of the s-wave state.

cond-mat.quant-gas↗

Stable vortex in Bose-Einstein condensate dark matter

The nature of dark matter (DM) is one of the most fascinating unresolved challenges of modern physics. One of the perspective hypotheses suggests that DM consists of ultralight bosonic particles in the state of Bose-Einstein condensate (BEC). The superfluid nature of BEC must dramatically affect the properties of DM matter including quantization of the angular momentum. Angular momentum quantum in the form of a vortex line is expected to produce a considerable impact on the luminous matter in galaxies including density distribution and rotation curves. We investigate the evolution of spinning DM cloud with typical galactic halo mass and radius. Analytically and numerically stationary vortex soliton states with different topological charges have been analyzed. It has been shown that while all multi-charged vortex states are unstable, a single-charged vortex soliton is extremely robust and survives during the lifetime of the Universe.

nlin.PS↗

Phase slips driven by acoustic waves in Bose-Einstein condensates with ring topology

Rotational superradiance is one of the most fascinating phenomena in black-hole physics. Here, with the aim of probing quantum properties of superradiance in the lab, we investigate the interaction of the acoustic waves with quantum vortices in Bose-Einstein condensates (BEC) in the framework of dissipative mean-field model. We find the conditions of the acoustic-induced quantum phase slips in condensates with ring topology and discuss the possibility of observing an acoustic analogue of quantum superradiance in ultracold atomic gases.

cond-mat.quant-gas↗

Spontaneous and engineered transformations of topological structures in nonlinear media with gain and loss

In contrast to conservative systems, in nonlinear media with gain and loss the dynamics of localized topological structures can exhibit unique features that can be controlled externally. We propose a robust mechanism to perform topological transformations changing characteristics of dissipative vortices and their complexes in a controllable way. We show that a properly chosen control carries out the evolution of dissipative structures to regime with spontaneous transformation of the topological excitations or drives generation of vortices with control over the topological charge.

nlin.PS↗

Spatiotemporal vortex rings in atomic Bose-Einstein condensates

We investigate spatiotemporal vortex rings with phase dislocation both in space and time. It is demonstrated that these structures naturally appear as a periodical in time edge phase dislocation at the low-density region of a perturbed atomic Bose-Einstein condensate. The condition of formation, dynamics and stability of the spatiotemporal vortex rings are investigated for repulsive and attractive interatomic interactions. These theoretical findings open up a perspective for experimental observation of novel type of topological coherent structures in ultracold gases.

cond-mat.quant-gas↗

Analogues of Josephson junctions and black hole event horizons in atomic Bose-Einstein condensates

We study dynamical processes in coherently coupled atomic Bose-Einstein condensates. Josephson effects in ring-shaped and dumbbell geometries are theoretically investigated. Conditions for observation of the Josephson effect are revealed. We found that multicharged persistent current in toroidal condensate can be robust even for supersonic atomic flow. In numerical simulations the acoustic analogues of event horizon in quantized superflow was observed. These theoretical finding open perspectives for investigation of Bose Josephson junctions and quantum aspects of acoustic analogue of Hawking radiation in existing experimental setups.

cond-mat.quant-gas↗

p-wave superfluidity in mixtures of ultracold Fermi and spinor Bose gases

We reveal that the p-wave superfluid can be realized in a mixture of fermionic and F=1 bosonic gases. We derive a general set of the gap equations for gaps in the s- and p-channels. It is found that the spin-spin bose-fermi interactions favor the p-wave pairing and naturally suppress the pairing in the s-channel. The gap equations for the polar phase of p-wave superfluid fermions are numerically solved. It is shown that a pure p-wave superfluid can be observed in a well-controlled environment of atomic physics.

cond-mat.quant-gas↗

Solitons with rings and vortex rings on solitons in nonlocal nonlinear media

Nonlocality is a key feature of many physical systems since it prevents a catastrophic collapse and a symmetry-breaking azimuthal instability of intense wave beams in a bulk self-focusing nonlinear media. This opens up an intriguing perspective for stabilization of complex topological structures such as higher-order solitons, vortex rings and vortex ring-on-line complexes. Using direct numerical simulations, we find a class of cylindrically-symmetric $n$-th order spatial solitons having the intensity distribution with a central bright spot surrounded by $n$ bright rings of varying size. We investigate dynamical properties of these higher-order solitons in a media with thermal nonlocal nonlinear response. We show theoretically that a vortex complex of vortex ring and vortex line, carrying two independent winding numbers, can be created by perturbation of the stable optical vortex soliton in nonlocal nonlinear media.

nlin.PS↗