We theoretically examine the finite-temperature spectral function of Fermi polarons in three dimensions by using a self-consistent many-body $T$ -matrix theory in real frequency. In comparison with the previous results from a non-self-consistent many-body $T$ -matrix approach, we show that the treatment of self-consistency in the impurity Green's function leads to notable changes in almost all the dynamical quantities, including the vertex function, impurity self-energy, and spectral function. Eventually, it gives rise to quantitatively different predictions for the measurable radio-frequency spectrum and Raman spectrum at finite temperature. Using the recent spectroscopic measurements as a benchmark, we find that the self-consistent many-body $T$ -matrix theory somehow provides a better explanation for the experimental data. The notable difference in the predictions from the non-self-consistent and self-consistent theories suggests that more accurate theoretical descriptions are needed in order to fully account for the current spectroscopic observations on Fermi polarons.We theoretically examine the finite-temperature spectral function of Fermi polarons in three dimensions by using a self-consistent many-body $T$-matrix theory in real frequency. In comparison with the previous results from a non-self-consistent many-body $T$-matrix approach, we show that the treatment of self-consistency in the impurity Green's function leads to notable changes in almost all the dynamical quantities, including the vertex function, impurity self-energy, and spectral function. Eventually, it gives rise to quantitatively different predictions for the measurable radio-frequency spectrum and Raman spectrum at finite temperature. Using the recent spectroscopic measurements as a benchmark, we find that the self-consistent many-body $T$-matrix theory somehow provides a better explanation for the experimental data. The notable difference in the predictions from the non-self-consistent and self-consistent theories suggests that more accurate theoretical descriptions are needed in order to fully account for the current spectroscopic observations on Fermi polarons.

arXiv:2311.11554Physical Review AJun 6, 20242 citations

Surface tension in heated nuclei

Yu. B. Ivanov

The method of thermal Green's functions is used to obtain a finite-temperature self-consistency condition for systems with spontaneously broken translational invariance; this condition makes it possible to calculate the equilibrium characteristics of a heated drop of a Fermi liquid. A model is proposed for describing a heated nucleus on the basis of a model self-consistency equation obtained from the exact self-consistency condition by means of the usual renormalization procedure in the theory of finite Fermi systems with neglect of retardation effects. It is shown that the model self-consistency condition makes it possible to describe a ''liquid-gas'' phase transition in nuclear matter and determine the corresponding critical temperature, which is a birfurcation point of this equation. In the framework of the developed approach, an expression is derived for the coefficient of surface tension at nonzero temperatures. The part played by retardation is discussed. It is shown that the contribution to the coefficient of surface tension of the effects associated with exchange of a surface excitation is dominant at low temperatures. In the low-temperature limit, an analytic form of the dependence of the coefficient of surface tension on the temperature is obtained.The method of thermal Green's functions is used to obtain a finite-temperature self-consistency condition for systems with spontaneously broken translational invariance; this condition makes it possible to calculate the equilibrium characteristics of a heated drop of a Fermi liquid. A model is proposed for describing a heated nucleus on the basis of a model self-consistency equation obtained from the exact self-consistency condition by means of the usual renormalization procedure in the theory of finite Fermi systems with neglect of retardation effects. It is shown that the model self-consistency condition makes it possible to describe a ''liquid-gas'' phase transition in nuclear matter and determine the corresponding critical temperature, which is a birfurcation point of this equation. In the framework of the developed approach, an expression is derived for the coefficient of surface tension at nonzero temperatures. The part played by retardation is discussed. It is shown that the contribution to the coefficient of surface tension of the effects associated with exchange of a surface excitation is dominant at low temperatures. In the low-temperature limit, an analytic form of the dependence of the coefficient of surface tension on the temperature is obtained.

Jul 1, 19810 citations

On The Theory of Interacting Fermi Systems

R. F. Bishop

Jan 1, 19720 citations

We theoretically examine the finite-temperature spectral function of Fermi polarons in three dimensions by using a self-consistent many-body

T

-matrix theory in real frequency. In comparison with the previous results from a non-self-consistent many-body

T

-matrix approach, we show that the treatment of self-consistency in the impurity Green's function leads to notable changes in almost all the dynamical quantities, including the vertex function, impurity self-energy, and spectral function. Eventually, it gives rise to quantitatively different predictions for the measurable radio-frequency spectrum and Raman spectrum at finite temperature. Using the recent spectroscopic measurements as a benchmark, we find that the self-consistent many-body

T

-matrix theory somehow provides a better explanation for the experimental data. The notable difference in the predictions from the non-self-consistent and self-consistent theories suggests that more accurate theoretical descriptions are needed in order to fully account for the current spectroscopic observations on Fermi polarons.