Based on the external field approach and the differential form of Ward identity, we derive a more compact formula for the particle-number susceptibility in QED3 at finite temperature. Using the zero frequency approxim...Based on the external field approach and the differential form of Ward identity, we derive a more compact formula for the particle-number susceptibility in QED3 at finite temperature. Using the zero frequency approximation the numerical value of the particle-number susceptibility is calculated in the Dyson-Schwinger approach for the case that the number of fermion flavours equals one and two, respectively. An enhanced fluctuation of the particlenumber density is observed across the transition temperature, which should be an essential characteristic of chiral phase transition in QED3.展开更多
Since the massless quantum electrodynamics in 2＋1 dimensions （QEDa） with nonzero gauge boson mass ζ can be used to explain some important traits of high-Tc superconductivity in planar cuprates, it is worthwhile to...Since the massless quantum electrodynamics in 2＋1 dimensions （QEDa） with nonzero gauge boson mass ζ can be used to explain some important traits of high-Tc superconductivity in planar cuprates, it is worthwhile to apply this model to analyze the nature of chiral phase transition at the critical value ζ. Based on the feature of chiral susceptibility, we show that the system at ζ exhibits a second-order phase transition which accords with the nature of appearance of the high-To superconductivity, and the estimated critical exponents around ζ are illustrated.展开更多
Using the coupled Dyson-Schwinger equation for the fermion propagator at finite chemical potential μ, we investigate the fermion chiral condensate when the gauge boson mass is nonzero in QED3. We show that the chiral...Using the coupled Dyson-Schwinger equation for the fermion propagator at finite chemical potential μ, we investigate the fermion chiral condensate when the gauge boson mass is nonzero in QED3. We show that the chiral symmetry restores when the boson mass is large enough, and the critical boson mass depends little on μ.展开更多
We propose a new method for calculating the dressed fermion propagator at finite chemical potential in QED3 under the rainbow approximation of Dyson-Schwinger equation. In the above approximation, we show that the dre...We propose a new method for calculating the dressed fermion propagator at finite chemical potential in QED3 under the rainbow approximation of Dyson-Schwinger equation. In the above approximation, we show that the dressed fermion propagator at finite chemical potential # has the form S（p） = iγ.p^-A（p^-2） ＋ B（ p^-2） with p^-μ= （p^-1p3 ＋ iμ）. Using this form of fermion propagator at nonzero chemical potential, we investigate the Dyson-Schwinger equation for the dressed fermion propagator at finite chemical potential and study the effects of the chemical potential on the critical number of the fermion flavors.展开更多
We derive the transverse Ward-Takahashi identities(WTI)of N-dimensional quantum electrodynamics by means of the canonical quantization method and the path integration method,and subsequently attempt to prove that QED3...We derive the transverse Ward-Takahashi identities(WTI)of N-dimensional quantum electrodynamics by means of the canonical quantization method and the path integration method,and subsequently attempt to prove that QED3 is solvable based on the transverse and longitudinal WTI,indicating that the full vector and tensor vertices functions can be expressed in terms of the fermion propagators in QED3.Further,we discuss the effect of differentγmatrix representations on the full vertex function.展开更多
Based on three-dimensional quantum electrodynamics theory,a set of truncated Dyson-Schwinger（D-S） equations are solved to study photon and fermion propagators with the effect of vacuum polarization.Numerical studies...Based on three-dimensional quantum electrodynamics theory,a set of truncated Dyson-Schwinger（D-S） equations are solved to study photon and fermion propagators with the effect of vacuum polarization.Numerical studies show that condensation and the value of fermion mass depends heavily on how the D-S equations are truncated.By solving a set of coupled D-S equations,it is also found that the fermion propagator shows a clear dependence on the order parameter.The truncated D-S equations under unquenched approximation are used to study the mass-function and chiral condensation of the fermions.The results under the unquenched approximation are clearly different from the ones under quenched approximation.With the increase in the order parameter,the fermion condensation in the unquenched approximation decreases when 0≤ξ5,while it increases when ξ5.However,nothing like this is observed in the quenched approximation,which indicates that there may be flaws in the quenched approximations.展开更多
In order to examine how a propagator behaves in non-perturbative theories and how its behavior is influenced by the choice of a covariant gauge a truncated Dyson-Schwinger equation is used to numerically investigate t...In order to examine how a propagator behaves in non-perturbative theories and how its behavior is influenced by the choice of a covariant gauge a truncated Dyson-Schwinger equation is used to numerically investigate the properties of fermions and bosons in 3D quantum electrodynamics QED and a series of self-consistent solutions for the fermion propagator in the Nambu and Wigner phases are obtained. These numerical solutions show that the propagator behaves very differently in the Landau gauge domain and in the infrared energy region outside it.By using the propagators in the Nambu and Wigner phases under various gauges it is further investigated how the fermion equivalent pressure difference and fermion condensation change with the gauge parameters.These results indicate that the phase transition described by the CJT equivalent potential and the chiral phase transition described by the chiral condensation are not completely identical.展开更多
Based on the study of the linear response of the fermion propagator to the presence of an external scalar field, a new method for calculating the staggered spin susceptibility in QED3 is presented, in which the influe...Based on the study of the linear response of the fermion propagator to the presence of an external scalar field, a new method for calculating the staggered spin susceptibility in QED3 is presented, in which the influence of the full vertex function is included. The numerical values of the staggered spin susceptibility are calculated within the framework of the rainbow-ladder approximation of the Dyson-Schwinger approach. A comparison between the result calculated using the full vertex and that using the bare vertex is given.展开更多
Adopting the approximation to the first order of chemical potential μ, we resolve rigidly the influence on fermion condensate from μ in QED3. We show that this condensate does not respond linear expression to μ. Mo...Adopting the approximation to the first order of chemical potential μ, we resolve rigidly the influence on fermion condensate from μ in QED3. We show that this condensate does not respond linear expression to μ. Moreover, the influence on fermion chiral condensate from chemieal potential is investigated.展开更多
In the case of nonzero fermion mass, within a range of Ansatze for the full fermion-boson vertex, we show that Dyson-Schwinger equation for the fermion propagator in QED3 has two qualitatively distinct dynamical chira...In the case of nonzero fermion mass, within a range of Ansatze for the full fermion-boson vertex, we show that Dyson-Schwinger equation for the fermion propagator in QED3 has two qualitatively distinct dynamical chiral symmetry breaking solutions. As the fermion mass increases and reaches to a critical value mc, one solution disappears, and the dependence of mc on the number of fermion flavors is also given.展开更多
In this paper, we investigate dynamical mass generation in（2＋1）-dimensional quantum electrodynamics at finite temperature. Many studies are carried out within the instantaneous-exchange approximation, which ignores...In this paper, we investigate dynamical mass generation in（2＋1）-dimensional quantum electrodynamics at finite temperature. Many studies are carried out within the instantaneous-exchange approximation, which ignores all but the zero-frequency component of the boson propagator and fermion self-energy function. We extend these studies by taking the retardation effects into consideration. In this paper, we get the explicit frequency n and momentum p dependence of the fermion self-energy function and identify the critical temperature for different fermion flavors in the chiral limit. Also, the phase diagram for spontaneous symmetry breaking in the theory is presented in Tc-Nf space. The results show that the chiral condensate is just one-tenth of the scale of previous results, and the chiral symmetry is restored at a smaller critical temperature.展开更多
In this letter,we propose to introduce a new Abelian gauge field Bμcorresponding to the so-called β symmetry into the normal Quantum Electrodynamics in 2+1 dimensions(QED3)of γ representation.The resulting theory i...In this letter,we propose to introduce a new Abelian gauge field Bμcorresponding to the so-called β symmetry into the normal Quantum Electrodynamics in 2+1 dimensions(QED3)of γ representation.The resulting theory is shown to be equivalent to QED3 containing two flavors of two-component fermions with mass of an opposite sign.We also show that Bμfield can generate a Chern-Simons term in perturbation theory.A comparison is made between the induced Chern-Simons term in theγrepresentation and that in Pauli representation.展开更多
In this paper,we investigate the behaviors of dual fermion condensate in QED 3 under variation of temperature.By means of Dyson-Schwinger equation for the fermion propagator,we extract the dual fermion condensate and ...In this paper,we investigate the behaviors of dual fermion condensate in QED 3 under variation of temperature.By means of Dyson-Schwinger equation for the fermion propagator,we extract the dual fermion condensate and compare its behavior with the ordinary chiral fermion condensate and the chiral susceptibility.It is found that the dual fermion condensate cannot be regarded as the order parameter for the confinement-deconfinement phase transition in QED 3.Furthermore,the change of the dual fermion condensate around the chiral phase transition point observed in the present work must therefore be interpreted as solely induced by the chiral transition.展开更多
基金Supported in part by the National Natural Science Foundation of China under Grant Nos 10575050 and 10775069, and the Research Fund for the Doctoral Programme of Higher Education under Grant No 20060284020.
文摘Based on the external field approach and the differential form of Ward identity, we derive a more compact formula for the particle-number susceptibility in QED3 at finite temperature. Using the zero frequency approximation the numerical value of the particle-number susceptibility is calculated in the Dyson-Schwinger approach for the case that the number of fermion flavours equals one and two, respectively. An enhanced fluctuation of the particlenumber density is observed across the transition temperature, which should be an essential characteristic of chiral phase transition in QED3.
基金Supported by the Natural Science Foundation of Jiangsu Province under Grant No BK20130387the Fundamental Research Funds for the Central Universities under Grant No 2242014R30011
文摘Since the massless quantum electrodynamics in 2＋1 dimensions （QEDa） with nonzero gauge boson mass ζ can be used to explain some important traits of high-Tc superconductivity in planar cuprates, it is worthwhile to apply this model to analyze the nature of chiral phase transition at the critical value ζ. Based on the feature of chiral susceptibility, we show that the system at ζ exhibits a second-order phase transition which accords with the nature of appearance of the high-To superconductivity, and the estimated critical exponents around ζ are illustrated.
基金We would like to thank Prof. Jia-Lun PING for helpful discussions.
文摘Using the coupled Dyson-Schwinger equation for the fermion propagator at finite chemical potential μ, we investigate the fermion chiral condensate when the gauge boson mass is nonzero in QED3. We show that the chiral symmetry restores when the boson mass is large enough, and the critical boson mass depends little on μ.
基金the National Natural Science Foundation of China under，高等学校博士学科点专项科研项目
文摘We propose a new method for calculating the dressed fermion propagator at finite chemical potential in QED3 under the rainbow approximation of Dyson-Schwinger equation. In the above approximation, we show that the dressed fermion propagator at finite chemical potential # has the form S（p） = iγ.p^-A（p^-2） ＋ B（ p^-2） with p^-μ= （p^-1p3 ＋ iμ）. Using this form of fermion propagator at nonzero chemical potential, we investigate the Dyson-Schwinger equation for the dressed fermion propagator at finite chemical potential and study the effects of the chemical potential on the critical number of the fermion flavors.
基金Supported in part by the National Natural Science Foundation of China(11475085,11535005,11690030)the National Major state Basic Research and Development(2016YFE0129300)the Anhui Provincial Natural Science Foundation(1908085MA15)。
文摘We derive the transverse Ward-Takahashi identities(WTI)of N-dimensional quantum electrodynamics by means of the canonical quantization method and the path integration method,and subsequently attempt to prove that QED3 is solvable based on the transverse and longitudinal WTI,indicating that the full vector and tensor vertices functions can be expressed in terms of the fermion propagators in QED3.Further,we discuss the effect of differentγmatrix representations on the full vertex function.
基金The Science Foundation of Southeast University,the National Natural Science Foundation of China (No. 11047005)
文摘Based on three-dimensional quantum electrodynamics theory,a set of truncated Dyson-Schwinger（D-S） equations are solved to study photon and fermion propagators with the effect of vacuum polarization.Numerical studies show that condensation and the value of fermion mass depends heavily on how the D-S equations are truncated.By solving a set of coupled D-S equations,it is also found that the fermion propagator shows a clear dependence on the order parameter.The truncated D-S equations under unquenched approximation are used to study the mass-function and chiral condensation of the fermions.The results under the unquenched approximation are clearly different from the ones under quenched approximation.With the increase in the order parameter,the fermion condensation in the unquenched approximation decreases when 0≤ξ5,while it increases when ξ5.However,nothing like this is observed in the quenched approximation,which indicates that there may be flaws in the quenched approximations.
基金The National Natural Science Foundation of China(No.10947127)the Science Foundation of Southeast University(No.11047005)
文摘In order to examine how a propagator behaves in non-perturbative theories and how its behavior is influenced by the choice of a covariant gauge a truncated Dyson-Schwinger equation is used to numerically investigate the properties of fermions and bosons in 3D quantum electrodynamics QED and a series of self-consistent solutions for the fermion propagator in the Nambu and Wigner phases are obtained. These numerical solutions show that the propagator behaves very differently in the Landau gauge domain and in the infrared energy region outside it.By using the propagators in the Nambu and Wigner phases under various gauges it is further investigated how the fermion equivalent pressure difference and fermion condensation change with the gauge parameters.These results indicate that the phase transition described by the CJT equivalent potential and the chiral phase transition described by the chiral condensation are not completely identical.
基金supported by National Natural Science Foundation of China under Grant No.10575050the Research Fund for the Doctoral Program of Higher Education under Grant No.20060284020
文摘Based on the study of the linear response of the fermion propagator to the presence of an external scalar field, a new method for calculating the staggered spin susceptibility in QED3 is presented, in which the influence of the full vertex function is included. The numerical values of the staggered spin susceptibility are calculated within the framework of the rainbow-ladder approximation of the Dyson-Schwinger approach. A comparison between the result calculated using the full vertex and that using the bare vertex is given.
基金Supported in Part by the Science Foundation of Southeast UniversityChina Postdoctoral Science Foundation Funded Project under Grant No.20070420192
文摘Adopting the approximation to the first order of chemical potential μ, we resolve rigidly the influence on fermion condensate from μ in QED3. We show that this condensate does not respond linear expression to μ. Moreover, the influence on fermion chiral condensate from chemieal potential is investigated.
文摘In the case of nonzero fermion mass, within a range of Ansatze for the full fermion-boson vertex, we show that Dyson-Schwinger equation for the fermion propagator in QED3 has two qualitatively distinct dynamical chiral symmetry breaking solutions. As the fermion mass increases and reaches to a critical value mc, one solution disappears, and the dependence of mc on the number of fermion flavors is also given.
基金Supported by National Natural Science Foundation of China(11475085,11535005,11690030)Natural Science Foundation of Jiangsu Province(BK20130387)Jiangsu Planned Projects for Postdoctoral Research Funds(1501035B)
文摘In this paper, we investigate dynamical mass generation in（2＋1）-dimensional quantum electrodynamics at finite temperature. Many studies are carried out within the instantaneous-exchange approximation, which ignores all but the zero-frequency component of the boson propagator and fermion self-energy function. We extend these studies by taking the retardation effects into consideration. In this paper, we get the explicit frequency n and momentum p dependence of the fermion self-energy function and identify the critical temperature for different fermion flavors in the chiral limit. Also, the phase diagram for spontaneous symmetry breaking in the theory is presented in Tc-Nf space. The results show that the chiral condensate is just one-tenth of the scale of previous results, and the chiral symmetry is restored at a smaller critical temperature.
基金supported in part by the National Natural Science Foundation of China(10935001 and 11075075)the Research Fund for the Doctoral Program of Higher Education(2012009111002)
文摘In this letter,we propose to introduce a new Abelian gauge field Bμcorresponding to the so-called β symmetry into the normal Quantum Electrodynamics in 2+1 dimensions(QED3)of γ representation.The resulting theory is shown to be equivalent to QED3 containing two flavors of two-component fermions with mass of an opposite sign.We also show that Bμfield can generate a Chern-Simons term in perturbation theory.A comparison is made between the induced Chern-Simons term in theγrepresentation and that in Pauli representation.
基金supported by the National Natural Science Foundation of China (Grant Nos.11047005,11105029,10935001 and 11075075)
文摘In this paper,we investigate the behaviors of dual fermion condensate in QED 3 under variation of temperature.By means of Dyson-Schwinger equation for the fermion propagator,we extract the dual fermion condensate and compare its behavior with the ordinary chiral fermion condensate and the chiral susceptibility.It is found that the dual fermion condensate cannot be regarded as the order parameter for the confinement-deconfinement phase transition in QED 3.Furthermore,the change of the dual fermion condensate around the chiral phase transition point observed in the present work must therefore be interpreted as solely induced by the chiral transition.
