NEW INSIGHT ON THE CHAIN STATES AND BOSE-EINSTEIN CONDENSATE IN LIGHT NUCLEI

2008 ◽  
Vol 17 (10) ◽  
pp. 2150-2154 ◽  
Author(s):  
S. YU. TORILOV ◽  
K. A. GRIDNEV ◽  
W. GREINER
Keyword(s):  
Cluster Model ◽  
Einstein Condensate ◽  
Light Nuclei ◽  
Einstein Condensation ◽  
Pitaevskii Equation ◽  
Deformed Nuclei ◽  
Bose Einstein Condensation ◽  
Bose Einstein Condensate ◽  
Alpha Cluster ◽  
Bose Einstein

The simple alpha-cluster model was used for the consideration of the chain states and Bose-Einstein condensation in the light self-conjugated nuclei. Obtained results were compared with predictions of the shell-model for the deformed nuclei, with calculations based on Gross-Pitaevskii equation and with recent experimental results.

scholarly journals Supersolidity of the $\alpha$ cluster structure in the nucleus $^{12}$C

2020 ◽  
Vol 2020 (4) ◽  
Author(s):  
S Ohkubo ◽  
J Takahashi ◽  
Y Yamanaka
Keyword(s):  
Cluster Model ◽  
Cluster Structure ◽  
Einstein Condensate ◽  
Effective Field ◽  
Ground Band ◽  
Model Based ◽  
Bose Einstein Condensate ◽  
Dilute Gas ◽  
Alpha Cluster ◽  
Bose Einstein

Abstract For more than half a century, the structure of $^{12}$C, such as the ground band, has been understood to be well described by the three $\alpha$ cluster model based on a geometrical crystalline picture. On the contrary, recently it has been claimed that the ground state of $^{12}$C is also well described by a nonlocalized cluster model without any of the geometrical configurations originally proposed to explain the dilute gas-like Hoyle state, which is now considered to be a Bose–Einstein condensate of $\alpha$ clusters. The challenging unsolved problem is how we can reconcile the two exclusive $\alpha$ cluster pictures of $^{12}$C, crystalline vs. nonlocalized structure. We show that the crystalline cluster picture and the nonlocalized cluster picture can be reconciled by noticing that they are a manifestation of supersolidity with properties of both crystallinity and superfluidity. This is achieved through a superfluid $\alpha$ cluster model based on effective field theory, which treats the Nambu–Goldstone zero mode rigorously. For several decades, scientists have been searching for a supersolid in nature. Nuclear $\alpha$ cluster structure is considered to be the first confirmed example of a stable supersolid.

EXCITON-PHONON PACKETS WITH BOSE–EINSTEIN CONDENSATE

2003 ◽  
Vol 17 (28) ◽  
pp. 5289-5293
Author(s):  
D. ROUBTSOV ◽  
Y. LÉPINE
Keyword(s):  
Wave Function ◽  
Coherent State ◽  
Einstein Condensate ◽  
Einstein Condensation ◽  
Inhomogeneous State ◽  
Bose Einstein Condensation ◽  
Bose Einstein Condensate ◽  
Bose Einstein

We discuss the possibility for a moving droplet of excitons and phonons to form a coherent state inside the packet. We describe such an inhomogeneous state in terms of Bose–Einstein condensation and prescribe it a macroscopic wave function. Existence and, thus, coherency of such a Bose-core inside the droplet can be checked experimentally if two moving packets are allowed to interact.

FRACTIONAL MATHEMATICAL INVESTIGATION OF BOSE–EINSTEIN CONDENSATION IN DILUTE 87Rb, 23Na AND 7Li ATOMIC GASES

2012 ◽  
Vol 26 (17) ◽  
pp. 1250096 ◽  
Author(s):  
HÜSEYİN ERTİK ◽  
HÜSEYİN ŞİRİN ◽  
DOǦAN DEMİRHAN ◽  
FEVZİ BÜYÜKKİLİÇ
Keyword(s):  
Three Dimensional ◽  
Einstein Condensate ◽  
Einstein Condensation ◽  
Atomic Gases ◽  
Transition Temperatures ◽  
Interparticle Interactions ◽  
Bose Einstein Condensation ◽  
Bose Einstein Condensate ◽  
Einstein Distribution ◽  
Bose Einstein

Although atomic Bose gases are experimentally investigated in the dilute regime, interparticle interactions play an important role on the transition temperatures of Bose–Einstein condensation. In this study, Bose–Einstein condensation is handled using fractional calculus for a Bose gas consisting of interacting bosons which are trapped in a three-dimensional harmonic oscillator. In this frame, in order to introduce the nonextensive effect, fractionally generalized Bose–Einstein distribution function which features Mittag–Leffler function is adopted. The dependence of the transition temperature of Bose–Einstein condensation on α (a measure of fractality of space) has been established. The transition temperatures for the dilute 87 Rb , 23 Na and 7 Li atomic gases have been obtained in consistent with experimental data and the nature of the interactions in the Bose–Einstein condensate has been enlightened. In the course of our investigations, we have arrived to the conclusion that for α < 1 attractive interactions and for α > 1 repulsive interactions are predominant.

Shock Waves in Bose–Einstein Condensation Under Gaussian White Noise

2018 ◽  
Vol 17 (03) ◽  
pp. 1850027
Author(s):  
Eren Tosyali
Keyword(s):  
White Noise ◽  
Gaussian White Noise ◽  
Hierarchical Cluster ◽  
Einstein Condensate ◽  
Einstein Condensation ◽  
Pitaevskii Equation ◽  
Bose Einstein Condensate ◽  
Cluster Analysis Method ◽  
Bose Einstein ◽  
Condensate System

We investigate the Gross–Pitaevskii equation with the tilted bichromatical optical lattice potential for finding the dynamics of a Bose–Einstein condensate system under the Gaussian white noise. We construct the Poincare sections of system based on the relations between the system parameters and solution behaviors to understand how its shock wave like dynamic could be affected by the noise. Also the hierarchical cluster analysis method investigation of the system is presented.

scholarly journals QUANTUM FLUCTUATION DYNAMICS DURING THE TRANSITION OF A MESOSCOPIC BOSONIC GAS INTO A BOSE–EINSTEIN CONDENSATE

2012 ◽  
Vol 11 (04) ◽  
pp. 1250027
Author(s):  
ALEXEJ SCHELLE
Keyword(s):  
Master Equation ◽  
Quantum Fluctuation ◽  
Einstein Condensate ◽  
Einstein Condensation ◽  
Bose Einstein Condensation ◽  
Bose Einstein Condensate ◽  
Saturation Stage ◽  
Fluctuation Dynamics ◽  
Bosonic Atoms ◽  
Bose Einstein

The condensate number distribution during the transition of a dilute, weakly interacting gas of N = 200 bosonic atoms into a Bose–Einstein condensate is modeled within number conserving master equation theory of Bose–Einstein condensation. Initial strong quantum fluctuations occuring during the exponential cycle of condensate growth reduce in a subsequent saturation stage, before the Bose gas finally relaxes towards the Gibbs–Boltzmann equilibrium.

Bose–Einstein condensation in a QUIC trap

2004 ◽  
Vol 82 (2) ◽  
pp. 81-102 ◽  
Author(s):  
B Lu ◽  
W A van Wijngaarden
Keyword(s):  
Optical Trap ◽  
Einstein Condensate ◽  
Einstein Condensation ◽  
Magneto Optical Trap ◽  
Energy Minimum ◽  
Free Expansion ◽  
Trap Energy ◽  
Bose Einstein Condensation ◽  
Bose Einstein Condensate ◽  
Bose Einstein

The apparatus and procedure required to generate a pure Bose-Einstein condensate (BEC) consisting of about half a million 87Rb atoms at a temperature of <60 nK with a phase density of >54 is described. The atoms are first laser cooled in a vapour cell magneto-optical trap (MOT) and subsequently transferred to an ultra-low pressure MOT. The atoms are loaded into a QUIC trap consisting of a pair of quadrupole coils and a Ioffe coil that generates a small finite magnetic field at the trap energy minimum to suppress Majorana transitions. Evaporation induced by an RF field lowers the temperature permitting the transition to BEC to be observed by monitoring the free expansion of the atoms after the trapping fields have been switched off.PACS Nos.: 03.75.Fi, 05.30.Jp, 32.80.Pj, 64.60.–i

scholarly journals Bose–Einstein condensation of dilute alpha clusters above the four-α threshold in 16O in the field theoretical superfluid cluster model

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
J Takahashi ◽  
Y Yamanaka ◽  
S Ohkubo
Keyword(s):  
Cluster Model ◽  
Level Structure ◽  
Cluster Structure ◽  
Einstein Condensation ◽  
Condensation Rate ◽  
Excitation Energies ◽  
Energy Level Structure ◽  
Bose Einstein Condensation ◽  
Alpha Cluster ◽  
Bose Einstein

Abstract Observed well-developed $\alpha$ cluster states in $^{16}$O located above the four-$\alpha$ threshold are investigated from the viewpoint of Bose–Einstein condensation of $\alpha$ clusters by using a field-theoretical superfluid cluster model in which the order parameter is defined. The experimental energy levels are reproduced well for the first time by calculation. In particular, the observed 16.7 MeV $0_7^+$ and 18.8 MeV $0_8^+$ states with low-excitation energies from the threshold are found to be understood as a manifestation of the states of the Nambu–Goldstone zero-mode operators, associated with the spontaneous symmetry-breaking of the global phase, which is caused by the Bose–Einstein condensation of the vacuum 15.1 MeV $0^+_6$ state with a dilute well-developed $\alpha$ cluster structure just above the threshold. This gives evidence of the existence of the Bose–Einstein condensate of $\alpha$ clusters in $^{16}$O. It is found that the emergence of the energy level structure with a well-developed $\alpha$ cluster structure above the threshold is robust, almost independently of the condensation rate of $\alpha$ clusters under significant condensation rate. The finding of the mechanism that causes the level structure that is similar to $^{12}$C to emerge above the four-$\alpha$ threshold in $^{16}$O reinforces the concept of Bose–Einstein condensation of $\alpha$ clusters in addition to $^{12}$C.

BOSE-EINSTEIN CONDENSATION OF ATOMS WITH ATTRACTIVE INTERACTION

1999 ◽  
Vol 13 (05n06) ◽  
pp. 625-631 ◽  
Author(s):  
N. AKHMEDIEV ◽  
M. P. DAS ◽  
A. V. VAGOV
Keyword(s):  
Statistical Physics ◽  
Scattering Length ◽  
Stationary Solutions ◽  
Attractive Potential ◽  
Einstein Condensation ◽  
Pitaevskii Equation ◽  
Bose Einstein Condensation ◽  
Three Body ◽  
Negative Scattering Length ◽  
Bose Einstein

We suggest that crucial effect on Bose-Einstein condensation in systems with attractive potential is three-body interaction. We investigate stationary solutions of the Gross-Pitaevskii equation with negative scattering length and a higher-order stabilising term in presence of an external parabolic potential. Stability properties of the condensate are similar to those for thermodynamic systems in statistical physics which have first order phase transitions. We have shown that there are three possible type of stationary solutions corresponding to stable, metastable and unstable phases. Results are discussed in relation to recently observed 7 Li condensate.

scholarly journals Do we need a non-perturbative theory of Bose-Einstein condensation?

2021 ◽  
Vol 2103 (1) ◽  
pp. 012200
Author(s):  
K G Zloshchastiev
Keyword(s):  
Phase Contrast ◽  
Einstein Condensate ◽  
Einstein Condensation ◽  
One Dimensional ◽  
Quantum Fluid ◽  
Bose Einstein Condensate ◽  
Dipole Force ◽  
Theoretical Assumptions ◽  
Bose Einstein ◽  
Best Fit

Abstract We recall the experimental data of one-dimensional axial propagation of sound near the center of the Bose-Einstein condensate cloud, which used the optical dipole force method of a focused laser beam and rapid sequencing of nondestructive phase-contrast images. We reanalyze these data within the general quantum fluid framework but without model-specific theoretical assumptions; using the standard best fit techniques. We demonstrate that some of their features cannot be explained by means of the perturbative two-body approximation and Gross-Pitaevskii model, and conjecture possible solutions.

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