Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2020 ( 1 )

2019 ( 33 )

2018 ( 281 )

2017 ( 260 )

Custom range...

Search Results: 1 - 10 of 17769 matches for " Lan Yin "
All listed articles are free for downloading (OA Articles)
Page 1 /17769
Display every page Item
Phase diagram of a Bose gas near a wide Feshbach resonance
Lan Yin
Physics , 2007, DOI: 10.1103/PhysRevA.77.043630
Abstract: In this paper, we study the phase diagram of a homogeneous Bose gas with a repulsive interaction near a wide Feshbach resonance at zero temperature. The Bose-Einstein-condensation (BEC) state of atoms is a metastable state. When the scattering length $a$ exceeds a critical value depending on the atom density $n$, $na^3>0.035$, the molecular excitation energy is imaginary and the atomic BEC state is dynamically unstable against molecule formation. The BEC state of diatomic molecules has lower energy, where the atomic excitation is gapped and the molecular excitation is gapless. However when the scattering length is above another critical value, $na^3>0.0164$, the molecular BEC state becomes a unstable coherent mixture of atoms and molecules. In both BEC states, the binding energy of diatomic molecules is reduced due to the many-body effect.
Spiral phase and phase separation of the double exchange model in the large-S limit
Lan Yin
Physics , 2003, DOI: 10.1103/PhysRevB.68.104433
Abstract: The phase diagram of the double exchange model is studied in the large-S limit at zero temperature in two and three dimensions. We find that the spiral state has lower energy than the canted antiferromagnetic state in the region between the antiferromagnetic phase and the ferromagnetic phase. At small doping, the spiral phase is unstable against phase separation due to its negative compressibility. When the Hund coupling is small, the system separates into spiral regions and antiferromagnetic regions. When the Hund coupling is large, the spiral phase disappears completely and the system separates into ferromagnetic regions and antiferromagnetic regions.
Collective excitations in a fermion-fermion mixture with different Fermi surfaces
Lan Yin
Physics , 2003, DOI: 10.1103/PhysRevA.68.055602
Abstract: In this paper, collective excitations in a homogeneous fermion-fermion mixture with different Fermi surfaces are studied. In the Fermi liquid phase, the zero-sound velocity is found to be larger than the largest Fermi velocity. With attractive interactions, the superfluid phase appears below a critical temperature, and the phase mode is the low-energy collective excitation. The velocity of the phase mode is proportional to the geometric mean of the two Fermi velocities. The difference between the two velocities may serve as a tool to detect the superfluid phase.
Analysis of Economic Factors Attracting FDI in West China since Reform and Opening-up
Wenfei Lan,Qie Yin
International Journal of Business and Management , 2009, DOI: 10.5539/ijbm.v4n2p26
Abstract: Since China performed the policy of reform and opening-up 30 years ago, foreign direct investment (FDI) has exerted important function in the quick development of economy, but the location factors of West China and East China are very different, and their attractions to FDI are not same. According to the location theory of FDI, in this article, taking the city of Chengdu as the example, we utilized the method of co-integration to empirically analyze the economic factors attracting FDI in West China in past 30 years since reform and opening-up. And the analysis results indicate that quicker economic growth, higher opening degree and investment in fixed assets are important economic factors to attract foreign investments for the city of Chengdu.
Evaluating Land Use Intensification Based on Entropy Method --- A Case Study of Hefei
Lan Yao,Qi Yin
Asian Social Science , 2012, DOI: 10.5539/ass.v8n7p54
Abstract: In this paper, we establish the index system of urban land intensive use evaluation from four aspects: land investment level, land utilization level, land output effect, land use ecological benefits. The entropy method is used to calculate indexes which measure the land intensive utilization in Hefei. According to the comprehensive evaluation model we can draw a conclusion that although the land intensive use level of Hefei was ascending from 2004 to 2008, it is still at low level in 2008. Finally, we make suggestions about how to improve the intensive use level in Hefei with the help of the integrated assessment value of each rule layer. The conclusion indicate that Hefei should solve land utilization problems by setting the target for land intensive utilization, optimizing the land use structure, improving the urban environment, enhancing the land use level, changing the direction of land utilization, only in theses ways the land utilization of Hefei will be intensive.
The three-body recombination of a condensed Bose gas near a Feshbach resonance
Yingyi Zhang,Lan Yin
Physics , 2005, DOI: 10.1103/PhysRevA.72.043607
Abstract: In this paper, we study the three-body recombination rate of a homogeneous dilute Bose gas with a Feshbach resonance at zero temperature. The ground state and excitations of this system are obtained. The three-body recombination in the ground state is due to the break-up of an atom pair in the quantum depletion and the formation of a molecule by an atom from the broken pair and an atom from the condensate. The rate of this process is in good agreement with the experiment on $^{23}$Na in a wide range of magnetic fields.
Low Temperature Correlation Lengths of Bilayer Heisenberg AntiFerromagnets and Neutron Scattering
Lan Yin,Sudip Chakravarty
Physics , 1997,
Abstract: The low temperature correlation length and the static structure factor are computed for bilayer antiferromagnets such as YBa_2Cu_3O_6. It is shown that energy integrated two-axis scan in neutron scattering experiments can be meaningfully interpreted to extract correlation length in such bilayer antiferromagnets despite intensity modulation in the momentum perpendicular to the layers. Thus, precise measurements of the spin-spin correlation length can be performed in the future, and the theoretical predictions can be tested. It is also shown how the same correlation length can be measured in nuclear magnetic resonance experiments.
Antiferromagnetism and superfluidity of a dipolar Fermi gas in a 2D optical lattice
Bo Liu,Lan Yin
Physics , 2011, DOI: 10.1103/PhysRevA.84.043630
Abstract: In a dipolar Fermi gas, the dipole-dipole interaction between fermions can be turned into a dipolar Ising interaction between pseduospins in the presence of an AC electric field. When trapped in a 2D optical lattice, such a dipolar Fermi gas has a very rich phase diagram at zero temperature, due to the competition between antiferromagnetism and superfluidity. At half filling, the antiferromagnetic state is the favored ground state. The superfluid state appears as the ground state at a smaller filling factor. In between there is a phase-separated region. The order parameter of the superfluid state can display different symmetries depending on the filling factor and interaction strength, including d-wave ($d$), extend s-wave ($xs$), or their linear combination ($xs+i\times d$). The implication for the current experiment is discussed.
Correlation energy of a homogeneous dipolar Fermi gas
Bo Liu,Lan Yin
Physics , 2011, DOI: 10.1103/PhysRevA.84.053603
Abstract: We study the normal state of a 3-$d$ homogeneous dipolar Fermi gas beyond the Hartree-Fock approximation. The correlation energy is found of the same order as the Fock energy, unusually strong for a Fermi-liquid system. As a result, the critical density of mechanical collapse is smaller than that estimated in the Hartree-Fock approximation. With the correlation energy included, a new energy functional is proposed for the trapped system, and its property is explored.
Phase slip in a superfluid Fermi gas near a Feshbach resonance
Lan Yin,Ping Ao
Physics , 2004, DOI: 10.1103/PhysRevA.71.041603
Abstract: In this paper, we study the properties of a phase slip in a superfluid Fermi gas near a Feshbach resonance. The phase slip can be generated by the phase imprinting method. Below the superfluid transition temperature, it appears as a dip in the density profile, and becomes more pronounced when the temperature is lowered. Therefore the phase slip can provide a direct evidence of the superfluid state. The condensation energy of the superfluid state can be extracted from the density profile of the phase slip, due to the unitary properties of the Fermi gas near the resonance. The width of the phase slip is proportional to the square root of the difference between the transition temperature and the temperature. The signature of the phase slip in the density profile becomes more robust across the BCS-BEC crossover.
Page 1 /17769
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.