博 士( 理 学 )氏名 横田 猛 論文題目 Functional-renormalization-group aided density-functional theory -ab-inito description of ground and excited states of quantum many-body systems -
We demonstrate for the first time that a density-functional-theory-aided
functional-renormalization-group (DFT-RG) method describes well the
characteristic features of the ground and excited states of an interacting
many-body system in a unified manner. The DFT-RG method is applied to a
(1+1)-dimensional spinless nuclear matter. For the ground state, the equation
of state (EOS) is calculated, and it is shown that the resultant saturation
energy, which is derived from the minimum point of the EOS with respect to the
density, is found to be close to the result of the Monte Carlo simulation. For
the excited states, the density--density spectral function is calculated, and
it is found that our result reproduces a notable feature of the
density--density spectral function of the non-linear Tomonaga-Luttinger liquid:
The spectral function has a singularity at the edge of its support of the
lower-energy side. These findings suggest that the DFT-RG method is a promising
first-principle scheme to analyze the excited states as well as the ground
states of quantum many-body systems starting from the inter-particle
interaction.
We demonstrate for the first time that a functional-renormalization-group aided density-functional theory (FRG-DFT) describes well the characteristic features of the excited states as well as the ground state of an interacting many-body system with an infinite number of particles in a unified manner. The FRG-DFT is applied to (1+1) D spinless nuclear matter. For the excited states, the density–density spectral function is calculated at the saturation point obtained in the framework of FRG-DFT, and it is found that our result reproduces a notable feature of the density–density spectral function of the nonlinear Tomonaga–Luttinger liquid: The spectral function has a singularity at the edge of its support on the lower-energy side. These findings suggest that the FRG-DFT is a promising first-principles scheme to analyze the excited states as well as the ground states of quantum many-body systems starting from the inter-particle interaction.
We demonstrate for the first time that a functional-renormalization-group aided density-functional theory (FRG-DFT) describes well the characteristic features of the excited states as well as the ground state of an interacting many-body system with an infinite number of particles in a unified manner. The FRG-DFT is applied to (1+1) D spinless nuclear matter. For the excited states, the density–density spectral function is calculated at the saturation point obtained in the framework of FRG-DFT, and it is found that our result reproduces a notable feature of the density–density spectral function of the nonlinear Tomonaga–Luttinger liquid: The spectral function has a singularity at the edge of its support on the lower-energy side. These findings suggest that the FRG-DFT is a promising first-principles scheme to analyze the excited states as well as the ground states of quantum many-body systems starting from the inter-particle interaction.