What is a Mott insulator transition?

What is a Mott insulator transition?

Mott transition is a transition from a metal to an insulator, driven by the strong interactions between electrons. One of the simplest models that can capture Mott transition is Hubbard model.

Are transition metals insulators?

It distinguished between conducting metals (with partially filled bands) and nonconducting insulators. However, in 1937 de Boer and Evert Verwey reported that many transition-metal oxides (such as NiO) with a partially filled d-band were poor conductors, often insulating.

Is NiO Mott insulator?

The physics of NiO is determined by the strong interactions occurring between the Ni 3d electrons. In the ground state NiO is an antiferromagnetic Mott insulator.

Why is MnO an insulator?

TiO and VO are metallic, because the 3d orbitals have significant overlap in the structure. However, CrO, MnO, FeO, CoO, and NiO are all insulators, because the 3d orbitals contract (and therefore Δ < U) going across the transition metal series.

What type of metal is an insulator?

Insulators oppose electrical current and make poor conductors. Some common conductors are copper, aluminum, gold, and silver. Some common insulators are glass, air, plastic, rubber, and wood. Insulators that can be polarized by an electric field are called dielectrics.

Why is NiO an insulator?

In the ground state NiO is an antiferromagnetic Mott insulator. In a Bloch insulator or in a semiconductor there is a gap because there are as many bands as electrons in the outer atomic shells. The electrons then fill all the bands without reaching the Fermi level.

What is a band insulator?

An insulator has a large gap between the valence band and the conduction band. The valence band is full as no electrons can move up to the conduction band.

Is MnO an insulator?

Is NiO an insulator?

NiO has previously been described as a large-gap, charge-transfer insulator, while our data show the valence and conduction states at the Fermi energy to be primarily of Ni d–character hybridized with a small amount of O p–character states, suggesting a mixture of charge-transfer and Mott-Hubbard character as described …

What is the metal-insulator transition?

Metal-insulator transitions are accompanied by huge resistivity changes, even over tens of orders of magnitude, and are widely observed in condensed-matter systems. This article presents the observations and current understanding of the metal-insulator transition with a pedagogical introduction to the subject.

What is Mott insulation upon heating?

Upon heating, however, the system undergoes a transition into a Mott insulating state, which only exists in a narrow temperature window.

What happens at the transition point of a metal?

Near the transition point the metallic state shows fluctuations and orderings in the spin, charge, and orbital degrees of freedom. The properties of these metals are frequently quite different from those of ordinary metals, as measured by transport, optical, and magnetic probes.

Where to study metal-insulator transitions in Japan?

Metal-insulator transitions Masatoshi Imada Institute for Solid State Physics, University of Tokyo, Roppongi, Minato-ku, Tokyo, 106, Japan Atsushi Fujimori Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113, Japan Yoshinori Tokura Department of Applied Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113, Japan