The energy of a unitary Fermi gas in the normal phase including the effect of induced interaction

2015 ◽  
Vol 29 (32) ◽  
pp. 1550207 ◽  
Author(s):  
Hao Gong ◽  
Xiao-Xia Ruan ◽  
Hou-Rong Pang ◽  
Hong-Shi Zong
Keyword(s):  
Experimental Data ◽  
Chemical Potential ◽  
Normal Phase ◽  
Fermi Gases ◽  
Matrix Approximation ◽  
Ultracold Fermi Gases ◽  
Self Consistent ◽  
Unitary Fermi Gas ◽  
T Matrix ◽  
Good Agreement

In this paper, taking into account the effect of the induced interaction, we calculate the energy of ultracold Fermi gases at unitarity in the framework of non-self-consistent T-matrix approximation (nTMA) above the critical temperature and compare the result with the experimental data and other theoretical calculation without induced interaction. Our calculated chemical potential is higher than the experimental data, but our calculated energy obtains a good agreement with Tokyo experiment for temperature range between [Formula: see text] and [Formula: see text].

Momentum distribution and the universal contact of a unitary Fermi gas with particle-hole fluctuation

2018 ◽  
Vol 32 (21) ◽  
pp. 1850249 ◽  
Author(s):  
Xiao-Xia Ruan ◽  
Hao Gong ◽  
Zheng-Ling Wang ◽  
Hong-Shi Zong
Keyword(s):  
Experimental Data ◽  
Momentum Distribution ◽  
Fermi Gas ◽  
Normal Phase ◽  
Large Momentum ◽  
Matrix Approximation ◽  
Self Consistent ◽  
Theoretical Predictions ◽  
Unitary Fermi Gas ◽  
T Matrix

We compute the momentum distribution of a homogeneous Fermi gas at unitarity in the normal phase within the framework of the non-self-consistent T-matrix approximation with particle-hole fluctuation. From the large-momentum behavior of momentum distribution, we obtain the contact for the unitary Fermi gas. We also compare our results with experimental data and other theoretical predictions.

The pressure and entropy of a unitary Fermi gas with particle-hole fluctuation

2018 ◽  
Vol 32 (01) ◽  
pp. 1750364
Author(s):  
Hao Gong ◽  
Xiao-Xia Ruan ◽  
Hong-Shi Zong
Keyword(s):  
Experimental Data ◽  
Fermi Gas ◽  
Experimental Measurements ◽  
Matrix Approximation ◽  
Self Consistent ◽  
Unitary Fermi Gas ◽  
T Matrix ◽  
Theoretical Results ◽  
Previous Prediction ◽  
Good Agreement

We calculate the pressure and entropy of a unitary Fermi gas based on universal relations combined with our previous prediction of energy which was calculated within the framework of the non-self-consistent T-matrix approximation with particle-hole fluctuation. The resulting entropy and pressure are compared with the experimental data and the theoretical results without induced interaction. For entropy, we find good agreement between our results with particle-hole fluctuation and the experimental measurements reported by ENS group and MIT experiment. For pressure, our results suffer from a systematic upshift compared to MIT data.

SPECTRAL FUNCTION AND DOS OF ULTRACOLD FERMI GASES IN THE NORMAL PHASE INCLUDING THE EFFECT OF INDUCED INTERACTION

2013 ◽  
Vol 27 (29) ◽  
pp. 1350214 ◽  
Author(s):  
HAO GONG ◽  
XIAO-XIA RUAN ◽  
LONG DU ◽  
WEI-MIN SUN ◽  
HONG-SHI ZONG
Keyword(s):  
Spectral Function ◽  
High Accuracy ◽  
Normal Phase ◽  
Fermi Gases ◽  
Matrix Approximation ◽  
Real Frequency ◽  
Ultracold Fermi Gases ◽  
Self Consistent ◽  
T Matrix ◽  
Frequency Axis

In this paper, taking into account the effect of the induced interaction, we calculate the spectral function and hence density of states (DOS) of ultracold Fermi gases within the framework of non-self-consistent T-matrix approximation (nTMA) in the normal phase. The corresponding equations are calculated on the real-frequency axis directly with high accuracy. Our result shows that pseudogap phenomenon still exists in the spectral function and DOS.

High-frequency tail of the radio-frequency spectrum in a unitary Fermi gas with particle–hole fluctuation

2018 ◽  
Vol 32 (24) ◽  
pp. 1850280
Author(s):  
Xiao-Xia Ruan ◽  
Fei Wang ◽  
Hao Gong ◽  
Zheng-Ling Wang ◽  
Hong-Shi Zong
Keyword(s):  
Radio Frequency ◽  
Frequency Spectrum ◽  
High Frequency ◽  
Ultracold Atoms ◽  
Fermi Gas ◽  
Normal Phase ◽  
Matrix Approximation ◽  
Self Consistent ◽  
Radio Frequency Spectrum ◽  
Unitary Fermi Gas

The contact plays an important role in the study of ultracold atoms. We determine the contact from the high-frequency asymptotic behavior of radio-frequency spectrum for a homogeneous Fermi gas at unitarity in the normal phase. The contact is obtained within the framework of the non-self-consistent T-matrix approximation with particle–hole fluctuation.

MOMENTUM RESOLVED RADIO FREQUENCY SPECTROSCOPY OF A UNITARY FERMI GAS WITH EXTENDED GMB APPROXIMATION

2014 ◽  
Vol 28 (04) ◽  
pp. 1450028 ◽  
Author(s):  
XIAO-XIA RUAN ◽  
HAO GONG ◽  
LONG DU ◽  
YU JIANG ◽  
WEI-MIN SUN ◽  
...  
Keyword(s):  
Radio Frequency ◽  
High Temperature Superconductivity ◽  
Fermi Gas ◽  
Normal Phase ◽  
Matrix Approximation ◽  
Frequency Spectra ◽  
Self Consistent ◽  
Unitary Fermi Gas ◽  
Different Temperatures ◽  
Radio Frequency Spectroscopy

In this paper, the momentum-resolved radio-frequency spectra of a unitary Fermi gas in the normal phase are presented and analyzed on the basis of the framework of the non-self-consistent T-matrix approximation with the extended Gorkov and Melik-Barkhudarov (GMB) approximation. We report the calculated occupied spectral intensity and energy distribution curves for different temperatures above T c . Our results indicate the existence of pseudogap phenomenon which would be helpful for further understanding of the pseudogap in high-temperature superconductivity.

Analysis of Experimental Data From Ship Trajectories of Turning Circles in a Regular Seaway

2010 ◽  
Author(s):  
Joseph T. Klamo ◽  
Ray-Qing Lin
Keyword(s):  
Experimental Data ◽  
Quantitative Analysis ◽  
Time Varying ◽  
Ship Maneuvering ◽  
New Findings ◽  
Self Consistent ◽  
Calm Water ◽  
Experimental Laboratory ◽  
Ship Tracks ◽  
Good Agreement

The accurate prediction of the track of a ship maneuvering in a seaway is one of the most important tasks in seakeeping. Most ship maneuvering studies, both experimental and numerical, focus on maneuvering in calm water. Recently, Lin and Klamo (2010) used the Digital Self-consistent Ship Experimental Laboratory (DiSSEL) to study the ship track of a turning circle maneuver in a wave field. In that study, it was shown that their simulated ship trajectories had good agreement with experimentally measured tracks. This agreement motivated the following quantitative analysis of the experimental data to characterize the effects that wave impacts have on turning circle ship tracks. Our method involves describing the ship trajectories as sinusoids with time-varying means. We also estimate the uncertainty in the results from our analysis of the experimental measurements. The quantitative analysis shows overall agreement with Lin and Klamo (2010). New findings are also discussed such as changes in the distance and time to complete the maneuver as well as the speed and preferred directions of a drifting turning circle.

Application of Visco-Plastic Self Consistent Approach to Model Deformation Characteristics of Magnesium with Different Textures

2011 ◽  
Vol 702-703 ◽  
pp. 80-84
Author(s):  
Apu Sarkar ◽  
J.K. Chakravartty
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Uniaxial Tensile ◽  
Deformation Characteristics ◽  
Self Consistent ◽  
Plastic Forming ◽  
Constitutive Response ◽  
Low Symmetry ◽  
Consistent Approach ◽  
Good Agreement

The viscoplastic self-consistent (VPSC) formulation is by now a well established approach for simulating texture development and constitutive response during plastic forming of high and low-symmetry polycrystals. In this work we have used the VPSC approach to model the uniaxial tensile and compressive deformation characteristics of pure magnesium with random and extruded texture. We compare our results with experimental data and find that they are in good agreement with the available experimental evidence.

scholarly journals Nitrogen Dissolution in Liquid Ga and Fe: Comprehensive Ab Initio Analysis, Relevance for Crystallization of GaN

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1306
Author(s):  
Jacek Piechota ◽  
Stanislaw Krukowski ◽  
Petro Sadovyi ◽  
Bohdan Sadovyi ◽  
Sylwester Porowski ◽  
...  
Keyword(s):  
Experimental Data ◽  
Molecular Dynamics ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Chemical Potential ◽  
Nitrogen Solubility ◽  
Molecular Nitrogen ◽  
Ideal Gas ◽  
The Difference ◽  
Good Agreement

The dissolution of molecular nitrogen in Ga and Fe was investigated by ab initio calculations and some complementary experiments. It was found that the N bonding inside these solvents is fundamentally different. For Ga, it is between Ga4s and Ga4p and N2p states whereas for Fe this is by N2p to Fe4s, Fe4p and Fe3d states. Accordingly, the energy of dissolution of N2 for arbitrarily chosen starting atomic configurations was 0.535 eV/mol and −0.299 eV/mol for Ga and Fe, respectively. For configurations optimized with molecular dynamics, the difference between the corresponding energy values, 1.107 eV/mol and 0.003 eV/mol, was similarly large. Full thermodynamic analysis of chemical potential was made employing entropy-derived terms in a Debye picture. The entropy-dependent terms were obtained via a normal conditions path to avoid singularity of ideal gas entropy at zero K. Nitrogen solubility as a function of temperature and N2 pressure was evaluated, being much higher for Fe than for Ga. For T=1800 K and p=104 bar, the N concentration in Ga was 3×10−3 at. fr. whereas for Fe, it was 9×10−2 at. fr. in very good agreement with experimental data. It indicates that liquid Fe could be a prospective solvent for GaN crystallization from metallic solutions.

Sign in / Sign up

Export Citation Format

Share Document