題目 | The unrestricted Gutzwiller+RPA
approach and its application to stripes in cuprates |
講師 | Professor Goetz
Seibold (Physik komplexer Systeme BTU Cottbus Germany, 東北大金研) |
日時 | 平成17年4月13日(水)
16:00- |
場所 | コラボレーションセンター 3階 コラボレーション室 (岡山大学津島キャン パス内 ) |
要旨 |
Many of the unconventional
properties of high-Tc superconductors in the underdoped regime of the
phase diagram can be understood from the assumption that the charge
carriers are susceptible towards charge and spin ordering. The
substantiation of this hypthesis requires a technique which is able to
deal with the excitations of an inhomogeneous, strongly correlated
system. In this talk I will present results from the time-dependent
Gutzwiller approximation for the Hubbard model which allows for the
computation of random-phase approximation (RPA) –like fluctuations on
top of the Gutzwiller approximation (GA). Within this formalism static
and dynamical properties of stripe textures in cuprates are
investigated. Besides a brief presentation of the technique and results
for the optical conductivity the main emphasis of the talk will be on
the discussion of magnetic excitations of stripes in connection with
recent neutron scattering experiments. It is shown that the GA+RPA
approach can account for the main features present in these spectra,
namely a low-energy incommensurate acoustic branch which merges into
a ``resonance peak'' at the antiferromagnetic (AF) wave vector
and high-energy AF-like optical branches.
|
世話人 | 理学部物理学科 町田一成(TEL:
086-251-7814) |