Geometrical-frustration-induced (Semi)metal-to-insulator transition.
نویسنده
چکیده
We study the low-energy properties of the geometrically frustrated Hubbard model on a three-dimensional pyrochlore lattice and a two-dimensional checkerboard lattice on the basis of the renormalization group method and mean field analysis. It is found that, in the half-filling case, a (semi)metal to insulator transition (MIT) occurs. Also, in the insulating phase, which has a spin gap, the spin rotational symmetry is not broken, while charge ordering exists. The results are applied to the description of the MIT observed in the pyrochlore system Tl2Ru2O7.
منابع مشابه
Antiferromagnetic Metal and Mott Transition on Shastry-Sutherland Lattice
The Shastry-Sutherland lattice, one of the simplest systems with geometrical frustration, which has an exact eigenstate by putting singlets on diagonal bonds, can be realized in a group of layered compounds and raises both theoretical and experimental interest. Most of the previous studies on the Shastry-Sutherland lattice are focusing on the Heisenberg model. Here we opt for the Hubbard model ...
متن کاملDynamical Mean Field Theory of the Antiferromagnetic Metal to Antiferromagnetic Insulator Transition
We study the zero temperature antiferromagnetic metal to antiferromagnetic insulator transition using dynamical mean field theory and exact diagonalization methods. We find two qualitatively different behaviors depending on the degree of magnetic correlations. For strong correlations combined with magnetic frustration, the transition can be described in terms of a renormalized Slater theory, wi...
متن کاملImpact of magnetic frustration on the Mott transition within a slave-boson mean-field theory
We investigate the paramagnetic-metal-to-antiferromagnetic-metal and antiferromagnetic-metal-toantiferromagnetic-insulator transitions using a slave-boson mean-field theory. To this effect, we discuss the ground state of the half-filled Hubbard model as a function of t8/t and correlation strength U, where t and t8 are the hopping amplitudes between nearest and next-nearest neighbors, respective...
متن کاملCarbon kagome lattice and orbital-frustration-induced metal-insulator transition for optoelectronics.
A three-dimensional elemental carbon kagome lattice, made of only fourfold-coordinated carbon atoms, is proposed based on first-principles calculations. Despite the existence of 60° bond angles in the triangle rings, widely perceived to be energetically unfavorable, the carbon kagome lattice is found to display exceptional stability comparable to that of C(60). The system allows us to study the...
متن کاملخواص ساختاری، الکتریکی و مغناطیسی منگنایتLa1-xCaxMnO3
Manganites are considered as subbranches of condensed matter physics with a great wealth of physical mechanisms. In this investigation we have studied the structural, electrical and magnetic properties of a series of La1-xCaxMnO3 manganite with x=0.1, 0.2, …,0.5. We observed that the crystal structure of this manganite, with small dopping, at room temperature is orthorhombic and by increasi...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Physical review letters
دوره 89 22 شماره
صفحات -
تاریخ انتشار 2002