Mott transition

About: Mott transition is a research topic. Over the lifetime, 2444 publications have been published within this topic receiving 78401 citations.

Impurity-induced Mott transitions in partially filled antiferromagnetic states

Abstract: In view of cuprate superconductors, effects of point-type repulsive impurity potential (V) on partially filled antiferromagnetic (AF) states are studied for a strongly correlated square-lattice Hubbard model (U/t = 12) with a diagonal transfer (t' = −0.3t), using a variational Monte Carlo method. To simplify interpretation, here we focus on the case of δ imp = δ, where δ imp and δ are densities of impurity sites and doped holes, respectively, with δ = 0.04 − 0.20. As a result, a filling-control-type Mott transition occurs at V = V M (~ 2t) irrespective of δ; a partially filled AF state becomes Mott insulating for V > V M. Such impurity-induced Mott transitions extensively appear beyond the above parameter settings.

Bandwidth Control and Symmetry Breaking in a Mott‐Hubbard Correlated Metal

Abstract: In Mott materials strong electron correlation yields a spectrum of complex electronic structures. Recent synthesis advancements open realistic opportunities for harnessing Mott physics to design transformative devices. However, a major bottleneck in realizing such devices remains the lack of control over the electron correlation strength. This stems from the complexity of the electronic structure, which often veils the basic mechanisms underlying the correlation strength. Here, we present control of the correlation strength by tuning the degree of orbital overlap using picometer-scale lattice engineering. We illustrate how bandwidth control and concurrent symmetry breaking can govern the electronic structure of a correlated $SrVO_3$ model system. We show how tensile and compressive biaxial strain oppositely affect the $SrVO_3$ in-plane and out-of-plane orbital occupancy, resulting in the partial alleviation of the orbital degeneracy. We derive and explain the spectral weight redistribution under strain and illustrate how high tensile strain drives the system towards a Mott insulating state. Implementation of such concepts will drive correlated electron phenomena closer towards new solid state devices and circuits. These findings therefore pave the way for understanding and controlling electron correlation in a broad range of functional materials, driving this powerful resource for novel electronics closer towards practical realization.

Mott Insulator to Superconductor VIA Pressure RVB Theory & Prediction of New Systems

Abstract: This paper summarizes my new work, on the nature of Mott transition in orbitally non degenerate spin-1/2 system, motivated by observation of Mott insulator superconductor transition in real systems. The structure of superexchange perturbation theory for a repulsive Hubbard model at half filling is analyzed and it suggests, under some conditions, a resonating valence bond (RVB) mechanism of Mott insulator to superconductor transition; charge ‘deconfinement’ is accompanied by electron pair derealization aided by a preexisting spin singlet correlations in the insulator. An RVB mean field theory at half filling illustrating our mechanism of Mott insulator-Superconductor transition is sketched. We identify some family of compounds as potential candidates for Mott insulator to superconductor transition under pressure: CuO, BaBiO 3 , thin films of La 2 CuO 4 or CaCuO 2 (infinite layer compound) under pressure or an effective ab-plane pressure/epitaxial compressive stress; synthesizing new compounds such as La 2 CuS 2 O 2 , La 2 CuS 4 or CaCuS 2 or compounds containing CuS 2 or CuSe 2 planes to mimic large ab-plane chemical pressure.

Electronic Transitions in Metals and Insulator-Metal Transitions

Abstract: In this chapter we take up transitions which change the electrical properties of metals or compounds by establishing a new ground state for the system. Changes in physical rather than chemical properties are involved in these transitions, in contrast to the events discussed in later chapters.