Thermodynamic Functions of Fermi Gas with Quadruple BCS-Type Binding Potential with $d_{x^2 - y^2 }$ -Wave-Pairing SymmetryThermodynamic Functions of Fermi Gas with Quadruple BCS-Type Binding Potential with $$d_{x^2 - y^2 }$$ -Wave-Pairing Symmetry

P. Tarasewicz

Journal of SuperconductivityJun 1, 20043 citations

New representations of the thermodynamic functions of fermi gases

Sergei I. Blinnikov, M. A. Rudzskiǐ

AstrophysicsJan 1, 19890 citations

Asymmetric two-component Fermi gas in two dimensions

Jia-jia Du, Chen Cheng, J.-Q. Liang

We analytically investigate superfluid phase in two dimension at zero temperature for asymmetric Fermi gas. Analytic expressions for both gap and chemical potentials at mean-field level are obtained as a function of binding energy and population imbalance when mass of different types of fermions is equal. We identify regions corresponding to normal, Sarma phase for different polarization, or mass ratio and discuss topological phase diagram in the BCS-BEC crossover and find that energy gap and chemical potential behave differently in these topological quantum phase. We also obtain the low-frequency and long-wavelength collective excitation spectrum and find sound velocity has a maximum when two types of mass are equal.We analytically investigate superfluid phase in two dimension at zero temperature for asymmetric Fermi gas. Analytic expressions for both gap and chemical potentials at mean-field level are obtained as a function of binding energy and population imbalance when mass of different types of fermions is equal. We identify regions corresponding to normal, Sarma phase for different polarization, or mass ratio and discuss topological phase diagram in the BCS-BEC crossover and find that energy gap and chemical potential behave differently in these topological quantum phase. We also obtain the low-frequency and long-wavelength collective excitation spectrum and find sound velocity has a maximum when two types of mass are equal.

Physical Review AAug 4, 200911 citations

Unitary Fermi Gas and BCS-BECCrossover

Soumik Mitra

In this thesis,we investigate the Unitary Fermi gas and its thermodynamic properties. We look into the problem using the Lowest Order Constrained Variational method,using the Jastrow correlation function and determine the thermodynamic quantities of interest around unitarity.From this variational calculation we calculate quantities like energy per particle and chemical potential and study their variation as a function of the s-wave scattering length. We find there are two energy branches which suggests that the way to approach unitarity is not unique.We compare our results with those found from toy model for unitary fermi gas,a single particle in a spherical box interacting with a fixed scatterer at the center of the cavity interactions being modelled by the fermi pseudo potential.We find a surprising qualitative agreement between the results obtained. We also study the BCS-BEC crossover in three dimension using mean field analysis, and evaluate quantities like gap parameter and chemical potential across the whole range of the crossover.In this thesis,we investigate the Unitary Fermi gas and its thermodynamic properties. We look into the problem using the Lowest Order Constrained Variational method,using the Jastrow correlation function and determine the thermodynamic quantities of interest around unitarity.From this variational calculation we calculate quantities like energy per particle and chemical potential and study their variation as a function of the s-wave scattering length. We find there are two energy branches which suggests that the way to approach unitarity is not unique.We compare our results with those found from toy model for unitary fermi gas,a single particle in a spherical box interacting with a fixed scatterer at the center of the cavity interactions being modelled by the fermi pseudo potential.We find a surprising qualitative agreement between the results obtained. We also study the BCS-BEC crossover in three dimension using mean field analysis, and evaluate quantities like gap parameter and chemical potential across the whole range of the crossover.

May 1, 20150 citations

Thermodynamics of a Strongly-Interacting Fermi Gas

Joseph M. Kinast

APSMay 1, 20052 citations

Reentrant BCS-BEC Crossover and a Superfluid-Insulator Transition in Optical Lattices

Zhaochuan Shen, Leo Radzihovsky, Victor Gurarie

We study the thermodynamics of a two-species Feshbach-resonant atomic Fermi gas in a periodic potential, focusing in a deep optical potential where a tight binding model is applicable. We show that for a more than half-filled band the gas exhibits a reentrant crossover with decreased detuning (increased attractive interaction), from a paired BCS superfluid to a Bose-Einstein condensate (BEC) of molecules of holes, back to the BCS superfluid, and finally to a conventional BEC of diatomic molecules. This behavior is associated with the nonmonotonic dependence of the chemical potential on detuning and the concomitant Cooper-pair or molecular size, larger in the BCS and smaller in the BEC regimes. For a single filled band we find a quantum phase transition from a band insulator to a BCS-BEC superfluid, and map out the corresponding phase diagram.We study the thermodynamics of a two-species Feshbach-resonant atomic Fermi gas in a periodic potential, focusing in a deep optical potential where a tight binding model is applicable. We show that for a more than half-filled band the gas exhibits a reentrant crossover with decreased detuning (increased attractive interaction), from a paired BCS superfluid to a Bose-Einstein condensate (BEC) of molecules of holes, back to the BCS superfluid, and finally to a conventional BEC of diatomic molecules. This behavior is associated with the nonmonotonic dependence of the chemical potential on detuning and the concomitant Cooper-pair or molecular size, larger in the BCS and smaller in the BEC regimes. For a single filled band we find a quantum phase transition from a band insulator to a BCS-BEC superfluid, and map out the corresponding phase diagram.

arXiv:1208.1300Physical Review LettersDec 12, 201218 citations

Thermodynamic Functions of Fermi Gas with Quadruple BCS-Type Binding Potential with

d_{x^2 - y^2 }

-Wave-Pairing Symmetry