We measured the infrared reflectivity of BaFe1.904Ni0.096As2 single crystal from room temperature down to 20 K. Two Drude terms and a Lorentz term well describe the real part of the optical conductivity σ1 （ω）. We...We measured the infrared reflectivity of BaFe1.904Ni0.096As2 single crystal from room temperature down to 20 K. Two Drude terms and a Lorentz term well describe the real part of the optical conductivity σ1 （ω）. We fit the reciprocal of static optical conductivity 1/σ1（0） by the power law ρ （T）=ρo＋ATn with n= 1.6. The ＂broad＂ Drude component exhibits an incoherent background with a T-independent scattering rate 1/τb, while the other ＂narrow＂ one reveals a T-quadratic scattering rate 1/τn, indicating a hidden Fermi-liquid behavior in BaFe1.904Nio.096As2 compound.展开更多
The emission of high-energy particles in 16O + 197Au collisions at energy 20 MeV / nucleon is considered within the framework of the time evolution of a hot spot taking into account the hydrodynamic compression and ex...The emission of high-energy particles in 16O + 197Au collisions at energy 20 MeV / nucleon is considered within the framework of the time evolution of a hot spot taking into account the hydrodynamic compression and expansion stages. In addition, the evaporation of the particles that are formed in the early (hot) stage of the evolution of the hot spot is included in the calculation of the spectrum. This leads to a hardening of the particle spectrum in its high-energy part, which is in agreement with experimental data.展开更多
Two series of Cdl-xInxNNi3 （0 〈 x 〈 0.2） and Cd1_yCuyNNi3 （0 〈 y 〈 0.2） samples were prepared from CdO, In203, CuO, and nickel powders under NH3 atmosphere at 773 K. The structural and physical properties were...Two series of Cdl-xInxNNi3 （0 〈 x 〈 0.2） and Cd1_yCuyNNi3 （0 〈 y 〈 0.2） samples were prepared from CdO, In203, CuO, and nickel powders under NH3 atmosphere at 773 K. The structural and physical properties were investigated by means of X-ray powder diffraction temperature-dependent resistivity and magnetic measurements. X-ray powder diffraction results showed that the Cd1-xInxNNi3 and Cd1_yCuyNNi3 compounds have a typical antiperovskite structure, and the CdNNi3, Cd0.9In0.1NNi3, and Cd0.9Cu0.1NNia compounds show metallic temperature-dependent resistivity and exhibit a Fermi liquid behavior at low temperature. In contrast to the paramagnetism previously reported, the CdNNi3 sample exhibits very soft and weak ferromagnetism, and no superconductivity was found in the Cd1-xInxNNi3 and Cdl-yCuyNNi3 samples down to 2 K. Each sample exhibited very soft and weak ferromagnetism, and the temperature dependence of the magnetization of the Cd1-xInxNNi3 and Cd1_yCuyNNi3 samples can be well fitted to the combination of a Bloch term and a Curie-Weiss term.展开更多
The effects of interchannel scattering of conduction electrons by the impu rity and repulsion of conduction electrons at the impurity site on the two-channel Kondo model are simultaneously considered in this paper.It ...The effects of interchannel scattering of conduction electrons by the impu rity and repulsion of conduction electrons at the impurity site on the two-channel Kondo model are simultaneously considered in this paper.It is shown that these two perturbations will substantially modify the usual local non-Fermi liquid behavior of the two-channel Kondo model.With bosonization and unitary transformations we find that the system can be transformed into a single channel Kondo model with anisotropy between longitudinal and transverse exchange couplings.Whatever for originally antiferromagnetic or ferromagnetic isotropic coupling,the system always flows to strong-coupling limit,which exhibits local Fermi liquid behavior at low temperatures.展开更多
We present an infrared spectroscopy study of charge dynamics in CaCo_2As_2 single crystal. In this material, the optical conductivity can be described by two Drude components with different scattering rates（1/τ）： ...We present an infrared spectroscopy study of charge dynamics in CaCo_2As_2 single crystal. In this material, the optical conductivity can be described by two Drude components with different scattering rates（1/τ）： a broad incoherent background and a narrow Drude component. By monitoring the temperature dependence, we find that only the narrow Drude component is temperature-dependent and determines the transport properties. Especially a Fermi liquid behavior of carriers is revealed by the T^2 behavior in the dc resistivity ρ_n and scattering rate 1/τ_n, indicating a coherent nature of quasiparticles in the narrow Drude subsystem.展开更多
We have studied the effect of hole-doping on the established scenerio of the first-order Mott metal-insulatortransition (MIT) at half-filling using dynamical mean-Seld theory and exact diagonalization technique. The M...We have studied the effect of hole-doping on the established scenerio of the first-order Mott metal-insulatortransition (MIT) at half-filling using dynamical mean-Seld theory and exact diagonalization technique. The Mott insu-lator state is changed into metallic state immediately as holes are doped into the system. The latter is expected to beFermi liquid. The previously found unanalytical structure of MIT no longer exists for doping as small as 2 percent. Wecompare our results with that obtained from Gutzwiller approximation.展开更多
Studying liquid water in a frame of band theory shows that varying a reduction-oxidation (RedOx) potential of aqueous solution can be identified as shifting Fermi level in its band gap. This medium becomes the reducti...Studying liquid water in a frame of band theory shows that varying a reduction-oxidation (RedOx) potential of aqueous solution can be identified as shifting Fermi level in its band gap. This medium becomes the reductive one when Fermi level is shifting to the conduction band due to populating hydroxonium level (H3O+/ H3O) by electrons and transforming water in a hypo-stoichiometric state, H2O1-│X│. Opposite in the hyper-stoichiometric one H2O1+│X│ Fermi level is shifting to the valence band due to populating hydroxide level OH/OH- by holes and the aqueous solution becomes the oxidative one. The energy difference between these electronic levels is estimated of 1.75 eV. It is shown that the standard half-reactions and the typical aqueous electrodes fix their RedOx potential only by the electrons and holes populations ([H3O],[OH]) of these local electronic levels in the band gap of non-stoichiometric water in the corresponding solutions.展开更多
We reveal and explain the scaling behavior of the thermopower S/T exhibited by the archetypal heavy-fermion （HF） metal YbRh2Si2 under the application of magnetic field B at temperature T. We show that the same scali...We reveal and explain the scaling behavior of the thermopower S/T exhibited by the archetypal heavy-fermion （HF） metal YbRh2Si2 under the application of magnetic field B at temperature T. We show that the same scaling is demonstrated by different HF compounds such as/3-YbA1B4 and the strongly correlated layered cobalt oxide [BiBa0.66K0.3602]CoO2. Using YbRh2Si2 as an example, we demonstrate that the scaling behavior of SIT is violated at the antiferromagnetic phase transition, while both the residual resistivity Po and the density of states, N, experience jumps at the phase transition, causing the thermopower to make two jumps and change its sign. Our elucidation is based on flattening of the single-particle spectrum that profoundly affects Po and N. To depict the main features of the SIT behavior, we construct a T-B schematic phase diagram of YbRh2Si2. Our calculated SIT for the HF compounds are in good agreement with experimental facts and support our observations.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11374345,11104335,and 91121004)the National Basic Research Program of China(Grant Nos.2012CB821403,2011CBA00107,and 2012CB921302)
文摘We measured the infrared reflectivity of BaFe1.904Ni0.096As2 single crystal from room temperature down to 20 K. Two Drude terms and a Lorentz term well describe the real part of the optical conductivity σ1 （ω）. We fit the reciprocal of static optical conductivity 1/σ1（0） by the power law ρ （T）=ρo＋ATn with n= 1.6. The ＂broad＂ Drude component exhibits an incoherent background with a T-independent scattering rate 1/τb, while the other ＂narrow＂ one reveals a T-quadratic scattering rate 1/τn, indicating a hidden Fermi-liquid behavior in BaFe1.904Nio.096As2 compound.
文摘The emission of high-energy particles in 16O + 197Au collisions at energy 20 MeV / nucleon is considered within the framework of the time evolution of a hot spot taking into account the hydrodynamic compression and expansion stages. In addition, the evaporation of the particles that are formed in the early (hot) stage of the evolution of the hot spot is included in the calculation of the spectrum. This leads to a hardening of the particle spectrum in its high-energy part, which is in agreement with experimental data.
基金Project supported by the National Natural Science Foundation of China （Grant No. 20871119）, the National Basic Research Program of China （973 Program） （Grant Nos. 2011CBA00112 and 2011CB808202）, and the Natural Science Foundation of Luzhou Medical College.
文摘Two series of Cdl-xInxNNi3 （0 〈 x 〈 0.2） and Cd1_yCuyNNi3 （0 〈 y 〈 0.2） samples were prepared from CdO, In203, CuO, and nickel powders under NH3 atmosphere at 773 K. The structural and physical properties were investigated by means of X-ray powder diffraction temperature-dependent resistivity and magnetic measurements. X-ray powder diffraction results showed that the Cd1-xInxNNi3 and Cd1_yCuyNNi3 compounds have a typical antiperovskite structure, and the CdNNi3, Cd0.9In0.1NNi3, and Cd0.9Cu0.1NNia compounds show metallic temperature-dependent resistivity and exhibit a Fermi liquid behavior at low temperature. In contrast to the paramagnetism previously reported, the CdNNi3 sample exhibits very soft and weak ferromagnetism, and no superconductivity was found in the Cd1-xInxNNi3 and Cdl-yCuyNNi3 samples down to 2 K. Each sample exhibited very soft and weak ferromagnetism, and the temperature dependence of the magnetization of the Cd1-xInxNNi3 and Cd1_yCuyNNi3 samples can be well fitted to the combination of a Bloch term and a Curie-Weiss term.
文摘The effects of interchannel scattering of conduction electrons by the impu rity and repulsion of conduction electrons at the impurity site on the two-channel Kondo model are simultaneously considered in this paper.It is shown that these two perturbations will substantially modify the usual local non-Fermi liquid behavior of the two-channel Kondo model.With bosonization and unitary transformations we find that the system can be transformed into a single channel Kondo model with anisotropy between longitudinal and transverse exchange couplings.Whatever for originally antiferromagnetic or ferromagnetic isotropic coupling,the system always flows to strong-coupling limit,which exhibits local Fermi liquid behavior at low temperatures.
基金Project supported by the National Basic Research Program of China (Grant Nos. 2012CB821400, 2012CB921302, and 2015CB921303)the National Natural Science Foundation of China (Grants Nos. 11274237, 91121004, 51228201, and 11004238)the support of the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘We present an infrared spectroscopy study of charge dynamics in CaCo_2As_2 single crystal. In this material, the optical conductivity can be described by two Drude components with different scattering rates（1/τ）： a broad incoherent background and a narrow Drude component. By monitoring the temperature dependence, we find that only the narrow Drude component is temperature-dependent and determines the transport properties. Especially a Fermi liquid behavior of carriers is revealed by the T^2 behavior in the dc resistivity ρ_n and scattering rate 1/τ_n, indicating a coherent nature of quasiparticles in the narrow Drude subsystem.
文摘We have studied the effect of hole-doping on the established scenerio of the first-order Mott metal-insulatortransition (MIT) at half-filling using dynamical mean-Seld theory and exact diagonalization technique. The Mott insu-lator state is changed into metallic state immediately as holes are doped into the system. The latter is expected to beFermi liquid. The previously found unanalytical structure of MIT no longer exists for doping as small as 2 percent. Wecompare our results with that obtained from Gutzwiller approximation.
文摘Studying liquid water in a frame of band theory shows that varying a reduction-oxidation (RedOx) potential of aqueous solution can be identified as shifting Fermi level in its band gap. This medium becomes the reductive one when Fermi level is shifting to the conduction band due to populating hydroxonium level (H3O+/ H3O) by electrons and transforming water in a hypo-stoichiometric state, H2O1-│X│. Opposite in the hyper-stoichiometric one H2O1+│X│ Fermi level is shifting to the valence band due to populating hydroxide level OH/OH- by holes and the aqueous solution becomes the oxidative one. The energy difference between these electronic levels is estimated of 1.75 eV. It is shown that the standard half-reactions and the typical aqueous electrodes fix their RedOx potential only by the electrons and holes populations ([H3O],[OH]) of these local electronic levels in the band gap of non-stoichiometric water in the corresponding solutions.
文摘We reveal and explain the scaling behavior of the thermopower S/T exhibited by the archetypal heavy-fermion （HF） metal YbRh2Si2 under the application of magnetic field B at temperature T. We show that the same scaling is demonstrated by different HF compounds such as/3-YbA1B4 and the strongly correlated layered cobalt oxide [BiBa0.66K0.3602]CoO2. Using YbRh2Si2 as an example, we demonstrate that the scaling behavior of SIT is violated at the antiferromagnetic phase transition, while both the residual resistivity Po and the density of states, N, experience jumps at the phase transition, causing the thermopower to make two jumps and change its sign. Our elucidation is based on flattening of the single-particle spectrum that profoundly affects Po and N. To depict the main features of the SIT behavior, we construct a T-B schematic phase diagram of YbRh2Si2. Our calculated SIT for the HF compounds are in good agreement with experimental facts and support our observations.
