Question Condensates

[Harry Costas]

Researchers are trying to understand all aspects properties of condensates,[

Submitted on 15 Jun 2025]

Electric Field Control of Spin Orbit Coupling and Circular Photogalvanic Effect in a True Ferrielectric Crystal​

Yunlin Lei, Xinyu Yang, Shouyu Wang, Daliang Zhang, Zitao Wang, Jiayou Zhang, Yihao Yang, Chuanshou Wang, Tianqi Xiao, Yinxin Bai, Junjiang Tian, Congcong Chen, Yu Han, Shuai Dong, Junling Wang

Materials possessing long range ordering of magnetic spins or electric dipoles have been the focus of condensed matter research. Among them, ferri-systems with two sublattices of unequal/noncollinear spins or electric dipoles are expected to combine the properties of ferro- and antiferro-systems, but lack experimental observations in single phase materials. This is particularly true for the ferrielectric system, since the electric dipoles usually can be redefined to incorporate the two sublattices into one, making it indistinguishable from ferroelectric. This raises doubts about whether or not ferrielectricity can be considered as an independent ferroic order. Here we report the observation of true ferrielectric behaviors in a hybrid single crystal (MV)[SbBr5] (MV2+ = N,N'-dimethyl-4,4'-bipyridinium or methylviologen), where the two electric dipole sublattices switch asynchronously, thus cannot be reduced to ferroelectric by redefining the unit cell. Furthermore, the complex dipole configuration imparts circularly polarized light sensitivity to the system. An electric field can modulate the non-collinear dipole sublattices and even induce a transition from ferrielectric to ferroelectric state, thereby tuning the helicity-dependent photocurrent. This study opens a new paradigm for the study of true irreducible ferrielectricity (a new class of polar system) and provides an effective approach to the electric field control of spin-orbit coupling and circular photogalvanic effect.

 

[Harry Costas]

Yet another research.
Condensates are becoming the most important compact body.

[Submitted on 16 Jun 2025]

Dark energy and QCD instanton vacuum in Friedmann-Lemaitre-Robertson-Walker universe​

M. M. Musakhanov

The standard model of the universe, lambdaCDM, is based on the Friedmann-Lemaitre-Robertson-Walker metric with flat 3-dim coordinate space and Friedmann equations. The cosmological constant lambda is providing the cancellations of the matter fields contributions in the flat space. The dynamical dark energy is appearing on over of the vacuum energy of matter fields at the flat space. Within the Standard Model the gluon Yang-Mills (YM) fields are playing the special role since specific properties of their vacuum, where the presence of the gluon condensate, provide the flat space nonperturbative vacuum energy. It is natural to apply the successful instanton liquid model (ILM) of the QCD vacuum and its lowest excitations. Our aim is to calculate the gluon YM fields contribution to the dark energy density. The result of the calculations is corresponding lambdaCDM. We find the equation-of-state parameters w_0=-1, w_a=0 in accordance with lambdaCDM, while the newest data give them at least in the range -0.91 <w_0< -0.73, -1.05< w_a <-0.65 requesting non-acceptable value of scalar glueball mass m to be very small and comparable with present value of Hubble constant H0.

 

[Harry Costas]

Condensate droplets are important in seeding stars.
Imagine 1cm condensate having a compaction of 10^30 released in an unconfined space.

[Submitted on 20 Jun 2025]

Quantum droplets in rapidly rotating two-dimensional Bose-Einstein condensates​

Zhen Cao, Siying Li, Zhendong Li, Xinyi Liu, Zhigang Wu, Mingyuan Sun

Recent experiments demonstrate that rapidly rotating Bose-Einstein condensates (BECs) near the lowest Landau level can self-organize into interaction-driven persistent droplet arrays. Inspired by this discovery, we investigate the formation and dynamics of single droplet and droplet arrays in rapidly rotating BECs. Guided by a rigorous theorem on localized many-body states for 2D interacting systems in a magnetic field, we construct single droplet and droplet arrays states which are shown to be stationary solutions to the Gross-Pitaevskii equation in the rotating frame. The single droplet is shown to be dynamically stable, which underpins its role as the basic unit in a droplet array. The stability of the droplet arrays is demonstrated by their dynamic formation from a phase engineered initial condensate. Our study sheds light onto the nature of the droplet state in a rapidly rotating BEC and offers a new approach for generating and manipulating quantum droplet arrays through designing the initial condensate phase.

 

[Harry Costas]

Condensate Phase Transitions is one of the most important subjects.

[Submitted on 12 Jun 2025]

Phase transitions in a holographic superfluid model with non-linear terms beyond the probe limit​

Zi-Qiang Zhao, Zhang-Yu Nie, Jing-Fei Zhang, Xin Zhang

We study the holographic s-wave superfluid model with 4th and 6th power self-interaction terms λ|ψ|4 and τ|ψ|6 with considering the full back-reaction of the matter fields on the metric in the 3+1 dimensional bulk. The self-interaction terms are good at controlling the condensate to realize various phase transitions, such as the zeroth-order, first-order, and second-order phase transitions within the single condensate s-wave superfluid model. Therefore, in this work, we are able to investigate the influence of the back-reaction strength on the various phase transitions, including the zeroth and first order phase transitions. In addition, we confirm that the influence of the 4th and 6th power terms on the superfluid phase transition in the case of finite back-reaction are qualitative the same as in the probe limit, thus present universality. We also plot the special value λs of the parameter λ at different back-reaction strength, below which the condensate grows to an opposite direction and is important in controlling the order of the superfluid phase transitions. Comparing the influence of the back-reaction parameter and that of the higher-order nonlinear coefficients, we see that the back-reaction strength brings in both the effective couplings similar to the 4th power and 6th power terms.

 

[Harry Costas]

Keep researching, never ending story.


[Submitted on 19 Jun 2025]

Durgapal-Fuloria Bose-Einstein condensate stars within f(R,T) gravity theory​

Meghanil Sinha, S. Surendra Singh

This manuscript studies the Bose-Einstein condensate (BEC) stars in the light of f(R,T) gravity here with Durgapal-Fuloria (DP) metric ansatz. The function under this study features as f(R,T)=R+2ηT, where η represents the coupling constant. With the help of it, we have formulated a stellar model describing the isotropic matter here within. Our analysis covers energy conditions, equation of state (EoS) parameter and gradients of the energy-momentum tensor components for a valid BEC stellar framework within f(R,T) gravitational theory with satisfactory results. The model's stability has been validated via multiple stability criteria viz., the velocity of sound, study of adiabetic index and surface redshift where all are found to be lying within the acceptable range for our stellar model. Thus in all the cases we have found our model to be stable and realistic. From the graphical representations the impact of the coupling constant and the parameter of the DP metric potential are clearly visible. Thus we can state that with all the above-mentioned features we have introduced new stellar solutions for BEC stars with enhanced precise results in this modified gravity.

 

[Harry Costas]

The Votex created by the condensate gives us an understanding of the jets formed by Black Holes and Neutron Stars, etc.

[Submitted on 21 Jun 2025]

Kinematic Imprints of vortex-lines of BEC Dark Matter on Baryonic Matter​

Iván Álvarez-Rios, Carlos Tena-Contreras, Francisco S. Guzmán

Our results demonstrate that vortex lines in Bose-Einstein Condensate Dark Matter (BECDM) can act as gravitational seeds that induce the condensation of baryonic matter, leading to localized gas accumulation even in the absence of imposed symmetries or rotation. Our analysis is based on the numerical solution of the system of equations for the BECDM gravitationally coupled to Euler equations for a compressible ideal gas (IG) that we use as a model of baryonic matter. Numerical simulations are constructed for various scenarios that start with a vortex solution for the BECDM and a randomly distributed ideal gas, with the aim of investigating whether the matter distribution and dynamics of the vortex influences the dynamics and distribution of the gas. We find that the gas condensation process is most efficient when the IG mass dominates over the BECDM, and when the IG has low initial velocity dispersion. We also find that strong bosonic self-interaction does not guarantee the vortex stability, instead, it can trigger dynamical instabilities that disrupt both the vortex structure and the surrounding gas. An interesting finding is that the vortex drives a persistent morphological signature on the gas, often in the form of ring-like features visible in projected density maps. These patterns survive nonlinear evolution and may serve as indirect tracers of vortex structures in BECDM halos, potentially offering a novel and testable observational probe of the model.

 

[Harry Costas]

It's exciting times, the amount of research into condensates is most impressive.

[Submitted on 23 Jun 2025]

The role of magnetic fields in ram pressure stripping of satellite galaxies in the circumgalactic medium around massive galaxies​

Thomas A. Rintoul (1), Freeke van de Voort (1), Andrew T. Hannington (1), Rüdiger Pakmor (2), Rebekka Bieri (3), Maria Werhahn (2), Rosie Y. Talbot (2) ((1) Cardiff, (2) MPA, (3) Zurich)

The presence of magnetic fields in galaxies and their haloes could have important consequences for satellite galaxies moving through the magnetised circumgalactic medium (CGM) of their host. We therefore study the effect of magnetic fields on ram pressure stripping of satellites in the CGM of massive galaxies. We use cosmological `zoom-in' simulations of three massive galaxy haloes (M_{\rm{200c}} = 10^{12.5-13}M_\odot), each simulated with and without magnetic fields. The fraction of gas retained after infall through the CGM across our full satellite sample shows no population-wide impact of magnetic fields on ram pressure stripping. However, for the most massive satellites, we find that twice as much gas is stripped without magnetic fields. The evolution of a galaxy's stripped tail is also strongly affected. Magnetic fields reduce turbulent mixing, significantly inhibiting the dispersion of metals into the host CGM. This suppressed mixing greatly reduces condensation from the host CGM onto the stripped tail. By studying the magnetic field structure, we find evidence of magnetic draping and attribute differences in the stripping rate to the draping layer. Differences in condensation from the host CGM are attributed to magnetic field lines aligned with the tail suppressing turbulent mixing. We simulate one halo with enhanced resolution in the CGM and show these results are converged with resolution, though the structure of the cool gas in the tail is not. Our results show that magnetic fields can play an important role in ram pressure stripping in galaxy haloes and should be included in simulations of galaxy formation.

 

[Harry Costas]

The properties of condensates. In a few more years, we will understand how they work. In so doing, to explain the Long jeopardy billions of years of our Sun and the dipolar jets of the Black Holes of the Milky Way and M87.

[Submitted on 24 Jun 2025]

Uncovering the origin of bound state in the continuum​

Zeyu Rao, Changling Zou, Yang Chen, Guangcan Guo, Ming Gong

Bound state in the continuum (BIC) and quasi-BIC represent a remarkable class of wave functions that disobey conventional intuition by exhibiting spatially localized modes embedded in the continuum spectrum. In recent years, these states have found important applications in interdisciplinary systems as a non-radiating mode with ultra-long lifetime. In these applications, a key question is how to convert a quasi-BIC into an exact BIC, and what the general criterion is for this transition. In this work, we uncover its origin using two steps in a two-band model with an arbitrary confining potential. Firstly, we demonstrate that a bound state coupled to a continuum band can yield quasi-BIC. Then, we show that tuning the coupling between the bands can convert the quasi-BIC into an exact BIC. In our theory, the real and complex poles of the spectra have a clear physical meaning for the quasi- and exact BICs, and we give the general criterion for exact BICs. Unlike previous proposals, our theory requires neither symmetry protection nor topological constraints and can be extended to a multiband model, providing a new framework for realizing BICs and offering new insights for their design in different fields, including photonics, acoustics, ultracold atoms and Bose-Einstein condensate with and without many-body interactions.

 

[Harry Costas]

Neutron Stars have a probable Quark core. Its properties set an example of Transient Condensates, where we have Neutron matter confining a Quark core.

[Submitted on 25 Jun 2025]

Anomalous Energy Injection in Turbulent Neutron Star Cores​

Anirudh Sivakumar, Pankaj Kumar Mishra, Ahmad A. Hujeirat, Paulsamy Muruganandam

Anomalous Energy Injection in Turbulent Neutron Star Cores

Neutron star glitches -- sudden increases in rotational frequency -- are thought to result from angular momentum transfer via quantized vortices in the superfluid core. Using a two-dimensional rotating atomic Bose-Einstein condensate with phenomenological damping and a pinning potential to mimic...

arxiv.org

 

[Harry Costas]

Scientists are onto the properties of condensates.

[Submitted on 26 Jun 2025]

Spontaneous Quantum Turbulence in a Newborn Bose-Einstein Condensate via the Kibble-Zurek Mechanism​

Seong-Ho Shinn, Matteo Massaro, Mithun Thudiyangal, Adolfo del Campo

The Kibble-Zurek mechanism (KZM) predicts the spontaneous formation of topological defects in a continuous phase transition driven at a finite rate. We propose the generation of spontaneous quantum turbulence (SQT) via the KZM during Bose-Einstein condensation induced by a thermal quench. Using numerical simulations of the stochastic projected Gross-Pitaevskii equation in two spatial dimensions, we describe the formation of a newborn Bose-Einstein condensate proliferated by quantum vortices. We establish the nonequilibrium universality of SQT through the Kibble-Zurek and Kolmogorov scaling of the incompressible kinetic energy.

 

[Harry Costas]

Interesting paper.

[Submitted on 26 Jun 2025]

Four types of phase transitions in interacting boson (meson) matter at high temperatures​

D. Anchishkin, V. Gnatovskyy, D. Zhuravel, I. Mishustin, H. Stoecker

The thermodynamics of the interacting system of relativistic particles and antiparticles in the presence of a Bose-Einstein condensate was investigated within the framework of the mean-field model. It is assumed that the total isospin (charge) density is conserved. We show that, depending on the strength of the interaction, a bosonic particle-antiparticle system exhibits four types of phase transitions to the condensate phase. Three types correspond to the second-order phase transition, while one is a first-order phase transition.

 

[Harry Costas]

Quantum droplets may lead to the seeding of stars.
Imagine a droplet 20mm compacted to 10^30, released from the confined core.
20 mm add 10^30 zeros

[Submitted on 27 Jun 2025]

Chiral Quantum Droplet in a Spin-Orbit Coupled Bose Gas​

Tianqi Luo, Xiaoling Cui

We report the formation of chiral quantum droplet in a spin-orbit coupled Bose gas, where the system turns to a self-bound droplet when moving towards a particular direction and remains gaseous otherwise. The chirality arises from the breaking of Galilean invariance by spin-orbit coupling, which enables the system to dynamically adjust its condensation momentum and spin polarization in response to its velocity. As a result, only towards a specific moving direction and beyond a critical velocity, the acquired spin polarization can trigger collective interactions sufficient for self-binding and drive a first-order transition from gas to droplet. We have mapped out a phase diagram of droplet, gas and their coexistence for realistic spin-orbit coupled 39K mixtures with tunable moving velocity and magnetic detuning. Our results have revealed the emergence of chirality in spin-orbit coupled quantum gases, which shed light on general chiral phenomena in moving systems with broken Galilean invariance.

 

[Harry Costas]

Submitted on 27 Jun 2025]

Bose-Einstein Condensate Dark Matter in the Core of Neutron Stars: Implications for Gravitational-wave Observations​

Samanwaya Mukherjee, P. S. Aswathi, Chiranjeeb Singha, Apratim Ganguly

We thoroughly investigate the scenario where dark matter is admixed with the ordinary nuclear matter in a neutron star, focusing on the finite temperature Bose-Einstein condensate (BEC) as the dark matter candidate. These hybrid configurations yield masses and radii that match observed values of pulsar mass-radius observation and adhere to dimensionless tidal Love number constraints from the binary neutron star merger event GW170817. By analyzing possible, stable mass-radius configurations and the dimensionless tidal Love number constraints, we determine the dark matter content in a nuclear matter whose masses and radii comply with these astrophysical limits. We perform our analyses with three models for the ordinary nuclear matter equation of state (EoS), APR4, MPA1, and SLy. Our analyses suggest that if APR4 is the correct nuclear matter EoS governing neutron stars in the Universe, and the components of this event were indeed dark matter admixed neutron stars, then the most likely dark matter fractions in their cores are approximately 5.65% and 7.97%, respectively. In contrast, for the other two EoSs considered, the predicted dark matter fractions are significantly higher, exceeding 12%. We also consider finite temperature BEC stars. We find that temperature has negligible effect on the stability criteria or tidal properties of these dark matter admixed neutron stars.

 

[Harry Costas]

Black Holes are Condensates.

Source: YouTube https://share.google/7WEbkfpgCuKzofcSO

Shared via the Google app

 

[Harry Costas]

Looks like the Space forum is closing

 

[Harry Costas]

[Submitted on 14 Jul 2025]

Hollow cylindrical droplets in a very strongly dipolar condensate​

S. K. Adhikari

A harmonically trapped Bose-Einstein condensate (BEC) leads to topologically trivial compact states. Because of the long-range nonlocal dipole-dipole interaction, a strongly dipolar BEC revealed many novel phenomena. Here we show that in a strongly dipolar BEC one can have a hollow cylindrical quasi-one-dimensional metastable droplet with ring topology while the system is trapped only in the

-

plane by a harmonic potential and a Gaussian hill potential at the center and untrapped along the polarization

axis. In this numerical investigation we use the imaginary-time propagation of a mean-field model where we include the Lee-Huang-Yang interaction, suitably modified for dipolar systems. Being metastable, these droplets are weakly stable and we use real-time propagation to investigate its dynamics and establish stability.